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) {
697 } else if (HeVAL(entry) == &PL_sv_placeholder) {
698 /* if we find a placeholder, we pretend we haven't found
702 if (flags & HVhek_FREEKEY)
705 return entry ? (void *) &HeVAL(entry) : NULL;
709 #ifdef DYNAMIC_ENV_FETCH /* %ENV lookup? If so, try to fetch the value now */
710 if (!(action & HV_FETCH_ISSTORE)
711 && SvRMAGICAL((const SV *)hv)
712 && mg_find((const SV *)hv, PERL_MAGIC_env)) {
714 const char * const env = PerlEnv_ENVgetenv_len(key,&len);
716 sv = newSVpvn(env,len);
718 return hv_common(hv, keysv, key, klen, flags,
719 HV_FETCH_ISSTORE|HV_DISABLE_UVAR_XKEY|return_svp,
725 if (!entry && SvREADONLY(hv) && !(action & HV_FETCH_ISEXISTS)) {
726 hv_notallowed(flags, key, klen,
727 "Attempt to access disallowed key '%"SVf"' in"
728 " a restricted hash");
730 if (!(action & (HV_FETCH_LVALUE|HV_FETCH_ISSTORE))) {
731 /* Not doing some form of store, so return failure. */
732 if (flags & HVhek_FREEKEY)
736 if (action & HV_FETCH_LVALUE) {
739 /* At this point the old hv_fetch code would call to hv_store,
740 which in turn might do some tied magic. So we need to make that
741 magic check happen. */
742 /* gonna assign to this, so it better be there */
743 /* If a fetch-as-store fails on the fetch, then the action is to
744 recurse once into "hv_store". If we didn't do this, then that
745 recursive call would call the key conversion routine again.
746 However, as we replace the original key with the converted
747 key, this would result in a double conversion, which would show
748 up as a bug if the conversion routine is not idempotent. */
749 return hv_common(hv, keysv, key, klen, flags,
750 HV_FETCH_ISSTORE|HV_DISABLE_UVAR_XKEY|return_svp,
752 /* XXX Surely that could leak if the fetch-was-store fails?
753 Just like the hv_fetch. */
757 /* Welcome to hv_store... */
760 /* Not sure if we can get here. I think the only case of oentry being
761 NULL is for %ENV with dynamic env fetch. But that should disappear
762 with magic in the previous code. */
765 PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */),
767 HvARRAY(hv) = (HE**)array;
770 oentry = &(HvARRAY(hv))[hash & (I32) xhv->xhv_max];
773 /* share_hek_flags will do the free for us. This might be considered
776 HeKEY_hek(entry) = share_hek_flags(key, klen, hash, flags);
777 else if (hv == PL_strtab) {
778 /* PL_strtab is usually the only hash without HvSHAREKEYS, so putting
779 this test here is cheap */
780 if (flags & HVhek_FREEKEY)
782 Perl_croak(aTHX_ S_strtab_error,
783 action & HV_FETCH_LVALUE ? "fetch" : "store");
785 else /* gotta do the real thing */
786 HeKEY_hek(entry) = save_hek_flags(key, klen, hash, flags);
788 HeNEXT(entry) = *oentry;
791 if (val == &PL_sv_placeholder)
792 HvPLACEHOLDERS(hv)++;
793 if (masked_flags & HVhek_ENABLEHVKFLAGS)
797 const HE *counter = HeNEXT(entry);
799 xhv->xhv_keys++; /* HvTOTALKEYS(hv)++ */
800 if (!counter) { /* initial entry? */
801 } else if (xhv->xhv_keys > xhv->xhv_max) {
803 } else if(!HvREHASH(hv)) {
806 while ((counter = HeNEXT(counter)))
809 if (n_links > HV_MAX_LENGTH_BEFORE_SPLIT) {
810 /* Use only the old HvKEYS(hv) > HvMAX(hv) condition to limit
811 bucket splits on a rehashed hash, as we're not going to
812 split it again, and if someone is lucky (evil) enough to
813 get all the keys in one list they could exhaust our memory
814 as we repeatedly double the number of buckets on every
815 entry. Linear search feels a less worse thing to do. */
822 return entry ? (void *) &HeVAL(entry) : NULL;
824 return (void *) entry;
828 S_hv_magic_check(HV *hv, bool *needs_copy, bool *needs_store)
830 const MAGIC *mg = SvMAGIC(hv);
832 PERL_ARGS_ASSERT_HV_MAGIC_CHECK;
837 if (isUPPER(mg->mg_type)) {
839 if (mg->mg_type == PERL_MAGIC_tied) {
840 *needs_store = FALSE;
841 return; /* We've set all there is to set. */
844 mg = mg->mg_moremagic;
849 =for apidoc hv_scalar
851 Evaluates the hash in scalar context and returns the result. Handles magic when the hash is tied.
857 Perl_hv_scalar(pTHX_ HV *hv)
861 PERL_ARGS_ASSERT_HV_SCALAR;
863 if (SvRMAGICAL(hv)) {
864 MAGIC * const mg = mg_find((const SV *)hv, PERL_MAGIC_tied);
866 return magic_scalarpack(hv, mg);
870 if (HvTOTALKEYS((const HV *)hv))
871 Perl_sv_setpvf(aTHX_ sv, "%ld/%ld",
872 (long)HvFILL(hv), (long)HvMAX(hv) + 1);
880 =for apidoc hv_delete
882 Deletes a key/value pair in the hash. The value's SV is removed from the
883 hash, made mortal, and returned to the caller. The C<klen> is the length of
884 the key. The C<flags> value will normally be zero; if set to G_DISCARD then
885 NULL will be returned. NULL will also be returned if the key is not found.
887 =for apidoc hv_delete_ent
889 Deletes a key/value pair in the hash. The value SV is removed from the hash,
890 made mortal, and returned to the caller. The C<flags> value will normally be
891 zero; if set to G_DISCARD then NULL will be returned. NULL will also be
892 returned if the key is not found. C<hash> can be a valid precomputed hash
893 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);
1040 /* If this is a stash and the key ends with ::, then someone is
1041 deleting a package. */
1042 if (sv && HvNAME(hv)) {
1043 if (keysv) key = SvPV(keysv, klen);
1044 if (klen > 1 && key[klen-2] == ':' && key[klen-1] == ':'
1045 && SvTYPE(sv) == SVt_PVGV) {
1046 const HV * const stash = GvHV((GV *)sv);
1047 if (stash && HvNAME(stash))
1048 mro_package_moved(NULL, stash, NULL, NULL, 0);
1052 if (SvOOK(hv) && entry == HvAUX(hv)->xhv_eiter /* HvEITER(hv) */)
1055 hv_free_ent(hv, entry);
1056 xhv->xhv_keys--; /* HvTOTALKEYS(hv)-- */
1057 if (xhv->xhv_keys == 0)
1058 HvHASKFLAGS_off(hv);
1062 if (SvREADONLY(hv)) {
1063 hv_notallowed(k_flags, key, klen,
1064 "Attempt to delete disallowed key '%"SVf"' from"
1065 " a restricted hash");
1068 if (k_flags & HVhek_FREEKEY)
1074 S_hsplit(pTHX_ HV *hv)
1077 register XPVHV* const xhv = (XPVHV*)SvANY(hv);
1078 const I32 oldsize = (I32) xhv->xhv_max+1; /* HvMAX(hv)+1 (sick) */
1079 register I32 newsize = oldsize * 2;
1081 char *a = (char*) HvARRAY(hv);
1083 int longest_chain = 0;
1086 PERL_ARGS_ASSERT_HSPLIT;
1088 /*PerlIO_printf(PerlIO_stderr(), "hsplit called for %p which had %d\n",
1089 (void*)hv, (int) oldsize);*/
1091 if (HvPLACEHOLDERS_get(hv) && !SvREADONLY(hv)) {
1092 /* Can make this clear any placeholders first for non-restricted hashes,
1093 even though Storable rebuilds restricted hashes by putting in all the
1094 placeholders (first) before turning on the readonly flag, because
1095 Storable always pre-splits the hash. */
1096 hv_clear_placeholders(hv);
1100 #if defined(STRANGE_MALLOC) || defined(MYMALLOC)
1101 Renew(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1102 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1108 Move(&a[oldsize * sizeof(HE*)], &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1111 Newx(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1112 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1117 Copy(HvARRAY(hv), a, oldsize * sizeof(HE*), char);
1119 Copy(HvAUX(hv), &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1121 Safefree(HvARRAY(hv));
1125 Zero(&a[oldsize * sizeof(HE*)], (newsize-oldsize) * sizeof(HE*), char); /* zero 2nd half*/
1126 xhv->xhv_max = --newsize; /* HvMAX(hv) = --newsize */
1127 HvARRAY(hv) = (HE**) a;
1130 for (i=0; i<oldsize; i++,aep++) {
1131 int left_length = 0;
1132 int right_length = 0;
1137 if (!entry) /* non-existent */
1141 if ((HeHASH(entry) & newsize) != (U32)i) {
1142 *oentry = HeNEXT(entry);
1143 HeNEXT(entry) = *bep;
1148 oentry = &HeNEXT(entry);
1153 /* I think we don't actually need to keep track of the longest length,
1154 merely flag if anything is too long. But for the moment while
1155 developing this code I'll track it. */
1156 if (left_length > longest_chain)
1157 longest_chain = left_length;
1158 if (right_length > longest_chain)
1159 longest_chain = right_length;
1163 /* Pick your policy for "hashing isn't working" here: */
1164 if (longest_chain <= HV_MAX_LENGTH_BEFORE_SPLIT /* split worked? */
1169 if (hv == PL_strtab) {
1170 /* Urg. Someone is doing something nasty to the string table.
1175 /* Awooga. Awooga. Pathological data. */
1176 /*PerlIO_printf(PerlIO_stderr(), "%p %d of %d with %d/%d buckets\n", (void*)hv,
1177 longest_chain, HvTOTALKEYS(hv), HvFILL(hv), 1+HvMAX(hv));*/
1180 Newxz(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1181 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1183 Copy(HvAUX(hv), &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1186 was_shared = HvSHAREKEYS(hv);
1188 HvSHAREKEYS_off(hv);
1193 for (i=0; i<newsize; i++,aep++) {
1194 register HE *entry = *aep;
1196 /* We're going to trash this HE's next pointer when we chain it
1197 into the new hash below, so store where we go next. */
1198 HE * const next = HeNEXT(entry);
1203 PERL_HASH_INTERNAL(hash, HeKEY(entry), HeKLEN(entry));
1208 = save_hek_flags(HeKEY(entry), HeKLEN(entry),
1209 hash, HeKFLAGS(entry));
1210 unshare_hek (HeKEY_hek(entry));
1211 HeKEY_hek(entry) = new_hek;
1213 /* Not shared, so simply write the new hash in. */
1214 HeHASH(entry) = hash;
1216 /*PerlIO_printf(PerlIO_stderr(), "%d ", HeKFLAGS(entry));*/
1217 HEK_REHASH_on(HeKEY_hek(entry));
1218 /*PerlIO_printf(PerlIO_stderr(), "%d\n", HeKFLAGS(entry));*/
1220 /* Copy oentry to the correct new chain. */
1221 bep = ((HE**)a) + (hash & (I32) xhv->xhv_max);
1222 HeNEXT(entry) = *bep;
1228 Safefree (HvARRAY(hv));
1229 HvARRAY(hv) = (HE **)a;
1233 Perl_hv_ksplit(pTHX_ HV *hv, IV newmax)
1236 register XPVHV* xhv = (XPVHV*)SvANY(hv);
1237 const I32 oldsize = (I32) xhv->xhv_max+1; /* HvMAX(hv)+1 (sick) */
1238 register I32 newsize;
1243 PERL_ARGS_ASSERT_HV_KSPLIT;
1245 newsize = (I32) newmax; /* possible truncation here */
1246 if (newsize != newmax || newmax <= oldsize)
1248 while ((newsize & (1 + ~newsize)) != newsize) {
1249 newsize &= ~(newsize & (1 + ~newsize)); /* get proper power of 2 */
1251 if (newsize < newmax)
1253 if (newsize < newmax)
1254 return; /* overflow detection */
1256 a = (char *) HvARRAY(hv);
1259 #if defined(STRANGE_MALLOC) || defined(MYMALLOC)
1260 Renew(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1261 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1267 Copy(&a[oldsize * sizeof(HE*)], &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1270 Newx(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1271 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1276 Copy(HvARRAY(hv), a, oldsize * sizeof(HE*), char);
1278 Copy(HvAUX(hv), &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1280 Safefree(HvARRAY(hv));
1283 Zero(&a[oldsize * sizeof(HE*)], (newsize-oldsize) * sizeof(HE*), char); /* zero 2nd half*/
1286 Newxz(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize), char);
1288 xhv->xhv_max = --newsize; /* HvMAX(hv) = --newsize */
1289 HvARRAY(hv) = (HE **) a;
1290 if (!xhv->xhv_keys /* !HvTOTALKEYS(hv) */) /* skip rest if no entries */
1294 for (i=0; i<oldsize; i++,aep++) {
1298 if (!entry) /* non-existent */
1301 register I32 j = (HeHASH(entry) & newsize);
1305 *oentry = HeNEXT(entry);
1306 HeNEXT(entry) = aep[j];
1310 oentry = &HeNEXT(entry);
1317 Perl_newHVhv(pTHX_ HV *ohv)
1320 HV * const hv = newHV();
1323 if (!ohv || !HvTOTALKEYS(ohv))
1325 hv_max = HvMAX(ohv);
1327 if (!SvMAGICAL((const SV *)ohv)) {
1328 /* It's an ordinary hash, so copy it fast. AMS 20010804 */
1330 const bool shared = !!HvSHAREKEYS(ohv);
1331 HE **ents, ** const oents = (HE **)HvARRAY(ohv);
1333 Newx(a, PERL_HV_ARRAY_ALLOC_BYTES(hv_max+1), char);
1336 /* In each bucket... */
1337 for (i = 0; i <= hv_max; i++) {
1339 HE *oent = oents[i];
1346 /* Copy the linked list of entries. */
1347 for (; oent; oent = HeNEXT(oent)) {
1348 const U32 hash = HeHASH(oent);
1349 const char * const key = HeKEY(oent);
1350 const STRLEN len = HeKLEN(oent);
1351 const int flags = HeKFLAGS(oent);
1352 HE * const ent = new_HE();
1353 SV *const val = HeVAL(oent);
1355 HeVAL(ent) = SvIMMORTAL(val) ? val : newSVsv(val);
1357 = shared ? share_hek_flags(key, len, hash, flags)
1358 : save_hek_flags(key, len, hash, flags);
1369 HvTOTALKEYS(hv) = HvTOTALKEYS(ohv);
1373 /* Iterate over ohv, copying keys and values one at a time. */
1375 const I32 riter = HvRITER_get(ohv);
1376 HE * const eiter = HvEITER_get(ohv);
1377 STRLEN hv_fill = HvFILL(ohv);
1379 /* Can we use fewer buckets? (hv_max is always 2^n-1) */
1380 while (hv_max && hv_max + 1 >= hv_fill * 2)
1381 hv_max = hv_max / 2;
1385 while ((entry = hv_iternext_flags(ohv, 0))) {
1386 SV *const val = HeVAL(entry);
1387 (void)hv_store_flags(hv, HeKEY(entry), HeKLEN(entry),
1388 SvIMMORTAL(val) ? val : newSVsv(val),
1389 HeHASH(entry), HeKFLAGS(entry));
1391 HvRITER_set(ohv, riter);
1392 HvEITER_set(ohv, eiter);
1399 =for apidoc Am|HV *|hv_copy_hints_hv|HV *ohv
1401 A specialised version of L</newHVhv> for copying C<%^H>. I<ohv> must be
1402 a pointer to a hash (which may have C<%^H> magic, but should be generally
1403 non-magical), or C<NULL> (interpreted as an empty hash). The content
1404 of I<ohv> is copied to a new hash, which has the C<%^H>-specific magic
1405 added to it. A pointer to the new hash is returned.
1411 Perl_hv_copy_hints_hv(pTHX_ HV *const ohv)
1413 HV * const hv = newHV();
1415 if (ohv && HvTOTALKEYS(ohv)) {
1416 STRLEN hv_max = HvMAX(ohv);
1417 STRLEN hv_fill = HvFILL(ohv);
1419 const I32 riter = HvRITER_get(ohv);
1420 HE * const eiter = HvEITER_get(ohv);
1422 while (hv_max && hv_max + 1 >= hv_fill * 2)
1423 hv_max = hv_max / 2;
1427 while ((entry = hv_iternext_flags(ohv, 0))) {
1428 SV *const sv = newSVsv(HeVAL(entry));
1429 SV *heksv = newSVhek(HeKEY_hek(entry));
1430 sv_magic(sv, NULL, PERL_MAGIC_hintselem,
1431 (char *)heksv, HEf_SVKEY);
1432 SvREFCNT_dec(heksv);
1433 (void)hv_store_flags(hv, HeKEY(entry), HeKLEN(entry),
1434 sv, HeHASH(entry), HeKFLAGS(entry));
1436 HvRITER_set(ohv, riter);
1437 HvEITER_set(ohv, eiter);
1439 hv_magic(hv, NULL, PERL_MAGIC_hints);
1444 Perl_hv_free_ent(pTHX_ HV *hv, register HE *entry)
1449 PERL_ARGS_ASSERT_HV_FREE_ENT;
1454 if (val && isGV(val) && isGV_with_GP(val) && GvCVu(val) && HvNAME_get(hv))
1455 mro_method_changed_in(hv); /* deletion of method from stash */
1457 if (HeKLEN(entry) == HEf_SVKEY) {
1458 SvREFCNT_dec(HeKEY_sv(entry));
1459 Safefree(HeKEY_hek(entry));
1461 else if (HvSHAREKEYS(hv))
1462 unshare_hek(HeKEY_hek(entry));
1464 Safefree(HeKEY_hek(entry));
1470 Perl_hv_delayfree_ent(pTHX_ HV *hv, register HE *entry)
1474 PERL_ARGS_ASSERT_HV_DELAYFREE_ENT;
1478 /* SvREFCNT_inc to counter the SvREFCNT_dec in hv_free_ent */
1479 sv_2mortal(SvREFCNT_inc(HeVAL(entry))); /* free between statements */
1480 if (HeKLEN(entry) == HEf_SVKEY) {
1481 sv_2mortal(SvREFCNT_inc(HeKEY_sv(entry)));
1483 hv_free_ent(hv, entry);
1487 =for apidoc hv_clear
1489 Clears a hash, making it empty.
1495 Perl_hv_clear(pTHX_ HV *hv)
1498 register XPVHV* xhv;
1502 DEBUG_A(Perl_hv_assert(aTHX_ hv));
1504 xhv = (XPVHV*)SvANY(hv);
1506 if (SvREADONLY(hv) && HvARRAY(hv) != NULL) {
1507 /* restricted hash: convert all keys to placeholders */
1509 for (i = 0; i <= xhv->xhv_max; i++) {
1510 HE *entry = (HvARRAY(hv))[i];
1511 for (; entry; entry = HeNEXT(entry)) {
1512 /* not already placeholder */
1513 if (HeVAL(entry) != &PL_sv_placeholder) {
1514 if (HeVAL(entry) && SvREADONLY(HeVAL(entry))) {
1515 SV* const keysv = hv_iterkeysv(entry);
1517 "Attempt to delete readonly key '%"SVf"' from a restricted hash",
1520 SvREFCNT_dec(HeVAL(entry));
1521 HeVAL(entry) = &PL_sv_placeholder;
1522 HvPLACEHOLDERS(hv)++;
1530 HvPLACEHOLDERS_set(hv, 0);
1532 Zero(HvARRAY(hv), xhv->xhv_max+1 /* HvMAX(hv)+1 */, HE*);
1535 mg_clear(MUTABLE_SV(hv));
1537 HvHASKFLAGS_off(hv);
1542 mro_isa_changed_in(hv);
1543 HvEITER_set(hv, NULL);
1548 =for apidoc hv_clear_placeholders
1550 Clears any placeholders from a hash. If a restricted hash has any of its keys
1551 marked as readonly and the key is subsequently deleted, the key is not actually
1552 deleted but is marked by assigning it a value of &PL_sv_placeholder. This tags
1553 it so it will be ignored by future operations such as iterating over the hash,
1554 but will still allow the hash to have a value reassigned to the key at some
1555 future point. This function clears any such placeholder keys from the hash.
1556 See Hash::Util::lock_keys() for an example of its use.
1562 Perl_hv_clear_placeholders(pTHX_ HV *hv)
1565 const U32 items = (U32)HvPLACEHOLDERS_get(hv);
1567 PERL_ARGS_ASSERT_HV_CLEAR_PLACEHOLDERS;
1570 clear_placeholders(hv, items);
1574 S_clear_placeholders(pTHX_ HV *hv, U32 items)
1579 PERL_ARGS_ASSERT_CLEAR_PLACEHOLDERS;
1586 /* Loop down the linked list heads */
1588 HE **oentry = &(HvARRAY(hv))[i];
1591 while ((entry = *oentry)) {
1592 if (HeVAL(entry) == &PL_sv_placeholder) {
1593 *oentry = HeNEXT(entry);
1594 if (entry == HvEITER_get(hv))
1597 hv_free_ent(hv, entry);
1601 HvTOTALKEYS(hv) -= (IV)HvPLACEHOLDERS_get(hv);
1602 if (HvKEYS(hv) == 0)
1603 HvHASKFLAGS_off(hv);
1604 HvPLACEHOLDERS_set(hv, 0);
1608 oentry = &HeNEXT(entry);
1613 /* You can't get here, hence assertion should always fail. */
1614 assert (items == 0);
1619 S_hfreeentries(pTHX_ HV *hv)
1621 /* This is the array that we're going to restore */
1622 HE **const orig_array = HvARRAY(hv);
1626 PERL_ARGS_ASSERT_HFREEENTRIES;
1632 /* If the hash is actually a symbol table with a name, look after the
1634 struct xpvhv_aux *iter = HvAUX(hv);
1636 name = iter->xhv_name;
1637 iter->xhv_name = NULL;
1642 /* orig_array remains unchanged throughout the loop. If after freeing all
1643 the entries it turns out that one of the little blighters has triggered
1644 an action that has caused HvARRAY to be re-allocated, then we set
1645 array to the new HvARRAY, and try again. */
1648 /* This is the one we're going to try to empty. First time round
1649 it's the original array. (Hopefully there will only be 1 time
1651 HE ** const array = HvARRAY(hv);
1654 /* Because we have taken xhv_name out, the only allocated pointer
1655 in the aux structure that might exist is the backreference array.
1660 struct mro_meta *meta;
1661 struct xpvhv_aux *iter = HvAUX(hv);
1662 /* weak references: if called from sv_clear(), the backrefs
1663 * should already have been killed; if there are any left, its
1664 * because we're doing hv_clear() or hv_undef(), and the HV
1665 * will continue to live.
1666 * Because while freeing the entries we fake up a NULL HvARRAY
1667 * (and hence HvAUX), we need to store the backref array
1668 * somewhere else; but it still needs to be visible in case
1669 * any the things we free happen to call sv_del_backref().
1670 * We do this by storing it in magic instead.
1671 * If, during the entry freeing, a destructor happens to add
1672 * a new weak backref, then sv_add_backref will look in both
1673 * places (magic in HvAUX) for the AV, but will create a new
1674 * AV in HvAUX if it can't find one (if it finds it in magic,
1675 * it moves it back into HvAUX. So at the end of the iteration
1676 * we have to allow for this. */
1679 if (iter->xhv_backreferences) {
1680 if (SvTYPE(iter->xhv_backreferences) == SVt_PVAV) {
1681 /* The sv_magic will increase the reference count of the AV,
1682 so we need to drop it first. */
1683 SvREFCNT_dec(iter->xhv_backreferences);
1684 if (AvFILLp(iter->xhv_backreferences) == -1) {
1685 /* Turns out that the array is empty. Just free it. */
1686 SvREFCNT_dec(iter->xhv_backreferences);
1689 sv_magic(MUTABLE_SV(hv),
1690 MUTABLE_SV(iter->xhv_backreferences),
1691 PERL_MAGIC_backref, NULL, 0);
1696 sv_magic(MUTABLE_SV(hv), NULL, PERL_MAGIC_backref, NULL, 0);
1697 mg = mg_find(MUTABLE_SV(hv), PERL_MAGIC_backref);
1698 mg->mg_obj = (SV*)iter->xhv_backreferences;
1700 iter->xhv_backreferences = NULL;
1703 entry = iter->xhv_eiter; /* HvEITER(hv) */
1704 if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */
1706 hv_free_ent(hv, entry);
1708 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1709 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1711 if((meta = iter->xhv_mro_meta)) {
1712 if (meta->mro_linear_all) {
1713 SvREFCNT_dec(MUTABLE_SV(meta->mro_linear_all));
1714 meta->mro_linear_all = NULL;
1715 /* This is just acting as a shortcut pointer. */
1716 meta->mro_linear_current = NULL;
1717 } else if (meta->mro_linear_current) {
1718 /* Only the current MRO is stored, so this owns the data.
1720 SvREFCNT_dec(meta->mro_linear_current);
1721 meta->mro_linear_current = NULL;
1723 if(meta->mro_nextmethod) SvREFCNT_dec(meta->mro_nextmethod);
1724 SvREFCNT_dec(meta->isa);
1726 iter->xhv_mro_meta = NULL;
1729 /* There are now no allocated pointers in the aux structure. */
1731 SvFLAGS(hv) &= ~SVf_OOK; /* Goodbye, aux structure. */
1732 /* What aux structure? */
1735 /* make everyone else think the array is empty, so that the destructors
1736 * called for freed entries can't recursively mess with us */
1738 ((XPVHV*) SvANY(hv))->xhv_keys = 0;
1742 /* Loop down the linked list heads */
1743 HE *entry = array[i];
1746 register HE * const oentry = entry;
1747 entry = HeNEXT(entry);
1748 hv_free_ent(hv, oentry);
1752 /* As there are no allocated pointers in the aux structure, it's now
1753 safe to free the array we just cleaned up, if it's not the one we're
1754 going to put back. */
1755 if (array != orig_array) {
1760 /* Good. No-one added anything this time round. */
1765 /* Someone attempted to iterate or set the hash name while we had
1766 the array set to 0. We'll catch backferences on the next time
1767 round the while loop. */
1768 assert(HvARRAY(hv));
1770 if (HvAUX(hv)->xhv_name) {
1771 unshare_hek_or_pvn(HvAUX(hv)->xhv_name, 0, 0, 0);
1775 if (--attempts == 0) {
1776 Perl_die(aTHX_ "panic: hfreeentries failed to free hash - something is repeatedly re-creating entries");
1780 HvARRAY(hv) = orig_array;
1782 /* If the hash was actually a symbol table, put the name back. */
1784 /* We have restored the original array. If name is non-NULL, then
1785 the original array had an aux structure at the end. So this is
1787 SvFLAGS(hv) |= SVf_OOK;
1788 HvAUX(hv)->xhv_name = name;
1793 =for apidoc hv_undef
1801 Perl_hv_undef(pTHX_ HV *hv)
1804 register XPVHV* xhv;
1809 DEBUG_A(Perl_hv_assert(aTHX_ hv));
1810 xhv = (XPVHV*)SvANY(hv);
1812 if ((name = HvNAME_get(hv)) && !PL_dirty)
1813 mro_isa_changed_in(hv);
1818 (void)hv_delete(PL_stashcache, name, HvNAMELEN_get(hv), G_DISCARD);
1819 hv_name_set(hv, NULL, 0, 0);
1821 SvFLAGS(hv) &= ~SVf_OOK;
1822 Safefree(HvARRAY(hv));
1823 xhv->xhv_max = 7; /* HvMAX(hv) = 7 (it's a normal hash) */
1825 HvPLACEHOLDERS_set(hv, 0);
1828 mg_clear(MUTABLE_SV(hv));
1834 Returns the number of hash buckets that happen to be in use. This function is
1835 wrapped by the macro C<HvFILL>.
1837 Previously this value was stored in the HV structure, rather than being
1838 calculated on demand.
1844 Perl_hv_fill(pTHX_ HV const *const hv)
1847 HE **ents = HvARRAY(hv);
1849 PERL_ARGS_ASSERT_HV_FILL;
1852 HE *const *const last = ents + HvMAX(hv);
1853 count = last + 1 - ents;
1858 } while (++ents <= last);
1863 static struct xpvhv_aux*
1864 S_hv_auxinit(HV *hv) {
1865 struct xpvhv_aux *iter;
1868 PERL_ARGS_ASSERT_HV_AUXINIT;
1871 Newxz(array, PERL_HV_ARRAY_ALLOC_BYTES(HvMAX(hv) + 1)
1872 + sizeof(struct xpvhv_aux), char);
1874 array = (char *) HvARRAY(hv);
1875 Renew(array, PERL_HV_ARRAY_ALLOC_BYTES(HvMAX(hv) + 1)
1876 + sizeof(struct xpvhv_aux), char);
1878 HvARRAY(hv) = (HE**) array;
1879 /* SvOOK_on(hv) attacks the IV flags. */
1880 SvFLAGS(hv) |= SVf_OOK;
1883 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1884 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1886 iter->xhv_backreferences = 0;
1887 iter->xhv_mro_meta = NULL;
1892 =for apidoc hv_iterinit
1894 Prepares a starting point to traverse a hash table. Returns the number of
1895 keys in the hash (i.e. the same as C<HvKEYS(hv)>). The return value is
1896 currently only meaningful for hashes without tie magic.
1898 NOTE: Before version 5.004_65, C<hv_iterinit> used to return the number of
1899 hash buckets that happen to be in use. If you still need that esoteric
1900 value, you can get it through the macro C<HvFILL(hv)>.
1907 Perl_hv_iterinit(pTHX_ HV *hv)
1909 PERL_ARGS_ASSERT_HV_ITERINIT;
1911 /* FIXME: Are we not NULL, or do we croak? Place bets now! */
1914 Perl_croak(aTHX_ "Bad hash");
1917 struct xpvhv_aux * const iter = HvAUX(hv);
1918 HE * const entry = iter->xhv_eiter; /* HvEITER(hv) */
1919 if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */
1921 hv_free_ent(hv, entry);
1923 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1924 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1929 /* used to be xhv->xhv_fill before 5.004_65 */
1930 return HvTOTALKEYS(hv);
1934 Perl_hv_riter_p(pTHX_ HV *hv) {
1935 struct xpvhv_aux *iter;
1937 PERL_ARGS_ASSERT_HV_RITER_P;
1940 Perl_croak(aTHX_ "Bad hash");
1942 iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
1943 return &(iter->xhv_riter);
1947 Perl_hv_eiter_p(pTHX_ HV *hv) {
1948 struct xpvhv_aux *iter;
1950 PERL_ARGS_ASSERT_HV_EITER_P;
1953 Perl_croak(aTHX_ "Bad hash");
1955 iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
1956 return &(iter->xhv_eiter);
1960 Perl_hv_riter_set(pTHX_ HV *hv, I32 riter) {
1961 struct xpvhv_aux *iter;
1963 PERL_ARGS_ASSERT_HV_RITER_SET;
1966 Perl_croak(aTHX_ "Bad hash");
1974 iter = hv_auxinit(hv);
1976 iter->xhv_riter = riter;
1980 Perl_hv_eiter_set(pTHX_ HV *hv, HE *eiter) {
1981 struct xpvhv_aux *iter;
1983 PERL_ARGS_ASSERT_HV_EITER_SET;
1986 Perl_croak(aTHX_ "Bad hash");
1991 /* 0 is the default so don't go malloc()ing a new structure just to
1996 iter = hv_auxinit(hv);
1998 iter->xhv_eiter = eiter;
2002 Perl_hv_name_set(pTHX_ HV *hv, const char *name, U32 len, U32 flags)
2005 struct xpvhv_aux *iter;
2008 PERL_ARGS_ASSERT_HV_NAME_SET;
2009 PERL_UNUSED_ARG(flags);
2012 Perl_croak(aTHX_ "panic: hv name too long (%"UVuf")", (UV) len);
2016 if (iter->xhv_name) {
2017 unshare_hek_or_pvn(iter->xhv_name, 0, 0, 0);
2023 iter = hv_auxinit(hv);
2025 PERL_HASH(hash, name, len);
2026 iter->xhv_name = name ? share_hek(name, len, hash) : NULL;
2030 Perl_hv_backreferences_p(pTHX_ HV *hv) {
2031 struct xpvhv_aux * const iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
2033 PERL_ARGS_ASSERT_HV_BACKREFERENCES_P;
2034 PERL_UNUSED_CONTEXT;
2036 return &(iter->xhv_backreferences);
2040 Perl_hv_kill_backrefs(pTHX_ HV *hv) {
2043 PERL_ARGS_ASSERT_HV_KILL_BACKREFS;
2048 av = HvAUX(hv)->xhv_backreferences;
2051 HvAUX(hv)->xhv_backreferences = 0;
2052 Perl_sv_kill_backrefs(aTHX_ MUTABLE_SV(hv), av);
2053 if (SvTYPE(av) == SVt_PVAV)
2059 hv_iternext is implemented as a macro in hv.h
2061 =for apidoc hv_iternext
2063 Returns entries from a hash iterator. See C<hv_iterinit>.
2065 You may call C<hv_delete> or C<hv_delete_ent> on the hash entry that the
2066 iterator currently points to, without losing your place or invalidating your
2067 iterator. Note that in this case the current entry is deleted from the hash
2068 with your iterator holding the last reference to it. Your iterator is flagged
2069 to free the entry on the next call to C<hv_iternext>, so you must not discard
2070 your iterator immediately else the entry will leak - call C<hv_iternext> to
2071 trigger the resource deallocation.
2073 =for apidoc hv_iternext_flags
2075 Returns entries from a hash iterator. See C<hv_iterinit> and C<hv_iternext>.
2076 The C<flags> value will normally be zero; if HV_ITERNEXT_WANTPLACEHOLDERS is
2077 set the placeholders keys (for restricted hashes) will be returned in addition
2078 to normal keys. By default placeholders are automatically skipped over.
2079 Currently a placeholder is implemented with a value that is
2080 C<&Perl_sv_placeholder>. Note that the implementation of placeholders and
2081 restricted hashes may change, and the implementation currently is
2082 insufficiently abstracted for any change to be tidy.
2088 Perl_hv_iternext_flags(pTHX_ HV *hv, I32 flags)
2091 register XPVHV* xhv;
2095 struct xpvhv_aux *iter;
2097 PERL_ARGS_ASSERT_HV_ITERNEXT_FLAGS;
2100 Perl_croak(aTHX_ "Bad hash");
2102 xhv = (XPVHV*)SvANY(hv);
2105 /* Too many things (well, pp_each at least) merrily assume that you can
2106 call iv_iternext without calling hv_iterinit, so we'll have to deal
2112 oldentry = entry = iter->xhv_eiter; /* HvEITER(hv) */
2113 if (SvMAGICAL(hv) && SvRMAGICAL(hv)) {
2114 if ( ( mg = mg_find((const SV *)hv, PERL_MAGIC_tied) ) ) {
2115 SV * const key = sv_newmortal();
2117 sv_setsv(key, HeSVKEY_force(entry));
2118 SvREFCNT_dec(HeSVKEY(entry)); /* get rid of previous key */
2124 /* one HE per MAGICAL hash */
2125 iter->xhv_eiter = entry = new_HE(); /* HvEITER(hv) = new_HE() */
2127 Newxz(k, HEK_BASESIZE + sizeof(const SV *), char);
2129 HeKEY_hek(entry) = hek;
2130 HeKLEN(entry) = HEf_SVKEY;
2132 magic_nextpack(MUTABLE_SV(hv),mg,key);
2134 /* force key to stay around until next time */
2135 HeSVKEY_set(entry, SvREFCNT_inc_simple_NN(key));
2136 return entry; /* beware, hent_val is not set */
2138 SvREFCNT_dec(HeVAL(entry));
2139 Safefree(HeKEY_hek(entry));
2141 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
2145 #if defined(DYNAMIC_ENV_FETCH) && !defined(__riscos__) /* set up %ENV for iteration */
2146 if (!entry && SvRMAGICAL((const SV *)hv)
2147 && mg_find((const SV *)hv, PERL_MAGIC_env)) {
2150 /* The prime_env_iter() on VMS just loaded up new hash values
2151 * so the iteration count needs to be reset back to the beginning
2155 oldentry = entry = iter->xhv_eiter; /* HvEITER(hv) */
2160 /* hv_iterint now ensures this. */
2161 assert (HvARRAY(hv));
2163 /* At start of hash, entry is NULL. */
2166 entry = HeNEXT(entry);
2167 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
2169 * Skip past any placeholders -- don't want to include them in
2172 while (entry && HeVAL(entry) == &PL_sv_placeholder) {
2173 entry = HeNEXT(entry);
2178 /* Skip the entire loop if the hash is empty. */
2179 if ((flags & HV_ITERNEXT_WANTPLACEHOLDERS)
2180 ? HvTOTALKEYS(hv) : HvUSEDKEYS(hv)) {
2182 /* OK. Come to the end of the current list. Grab the next one. */
2184 iter->xhv_riter++; /* HvRITER(hv)++ */
2185 if (iter->xhv_riter > (I32)xhv->xhv_max /* HvRITER(hv) > HvMAX(hv) */) {
2186 /* There is no next one. End of the hash. */
2187 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
2190 entry = (HvARRAY(hv))[iter->xhv_riter];
2192 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
2193 /* If we have an entry, but it's a placeholder, don't count it.
2195 while (entry && HeVAL(entry) == &PL_sv_placeholder)
2196 entry = HeNEXT(entry);
2198 /* Will loop again if this linked list starts NULL
2199 (for HV_ITERNEXT_WANTPLACEHOLDERS)
2200 or if we run through it and find only placeholders. */
2204 if (oldentry && HvLAZYDEL(hv)) { /* was deleted earlier? */
2206 hv_free_ent(hv, oldentry);
2209 /*if (HvREHASH(hv) && entry && !HeKREHASH(entry))
2210 PerlIO_printf(PerlIO_stderr(), "Awooga %p %p\n", (void*)hv, (void*)entry);*/
2212 iter->xhv_eiter = entry; /* HvEITER(hv) = entry */
2217 =for apidoc hv_iterkey
2219 Returns the key from the current position of the hash iterator. See
2226 Perl_hv_iterkey(pTHX_ register HE *entry, I32 *retlen)
2228 PERL_ARGS_ASSERT_HV_ITERKEY;
2230 if (HeKLEN(entry) == HEf_SVKEY) {
2232 char * const p = SvPV(HeKEY_sv(entry), len);
2237 *retlen = HeKLEN(entry);
2238 return HeKEY(entry);
2242 /* unlike hv_iterval(), this always returns a mortal copy of the key */
2244 =for apidoc hv_iterkeysv
2246 Returns the key as an C<SV*> from the current position of the hash
2247 iterator. The return value will always be a mortal copy of the key. Also
2254 Perl_hv_iterkeysv(pTHX_ register HE *entry)
2256 PERL_ARGS_ASSERT_HV_ITERKEYSV;
2258 return sv_2mortal(newSVhek(HeKEY_hek(entry)));
2262 =for apidoc hv_iterval
2264 Returns the value from the current position of the hash iterator. See
2271 Perl_hv_iterval(pTHX_ HV *hv, register HE *entry)
2273 PERL_ARGS_ASSERT_HV_ITERVAL;
2275 if (SvRMAGICAL(hv)) {
2276 if (mg_find((const SV *)hv, PERL_MAGIC_tied)) {
2277 SV* const sv = sv_newmortal();
2278 if (HeKLEN(entry) == HEf_SVKEY)
2279 mg_copy(MUTABLE_SV(hv), sv, (char*)HeKEY_sv(entry), HEf_SVKEY);
2281 mg_copy(MUTABLE_SV(hv), sv, HeKEY(entry), HeKLEN(entry));
2285 return HeVAL(entry);
2289 =for apidoc hv_iternextsv
2291 Performs an C<hv_iternext>, C<hv_iterkey>, and C<hv_iterval> in one
2298 Perl_hv_iternextsv(pTHX_ HV *hv, char **key, I32 *retlen)
2300 HE * const he = hv_iternext_flags(hv, 0);
2302 PERL_ARGS_ASSERT_HV_ITERNEXTSV;
2306 *key = hv_iterkey(he, retlen);
2307 return hv_iterval(hv, he);
2314 =for apidoc hv_magic
2316 Adds magic to a hash. See C<sv_magic>.
2321 /* possibly free a shared string if no one has access to it
2322 * len and hash must both be valid for str.
2325 Perl_unsharepvn(pTHX_ const char *str, I32 len, U32 hash)
2327 unshare_hek_or_pvn (NULL, str, len, hash);
2332 Perl_unshare_hek(pTHX_ HEK *hek)
2335 unshare_hek_or_pvn(hek, NULL, 0, 0);
2338 /* possibly free a shared string if no one has access to it
2339 hek if non-NULL takes priority over the other 3, else str, len and hash
2340 are used. If so, len and hash must both be valid for str.
2343 S_unshare_hek_or_pvn(pTHX_ const HEK *hek, const char *str, I32 len, U32 hash)
2346 register XPVHV* xhv;
2348 register HE **oentry;
2350 bool is_utf8 = FALSE;
2352 const char * const save = str;
2353 struct shared_he *he = NULL;
2356 /* Find the shared he which is just before us in memory. */
2357 he = (struct shared_he *)(((char *)hek)
2358 - STRUCT_OFFSET(struct shared_he,
2361 /* Assert that the caller passed us a genuine (or at least consistent)
2363 assert (he->shared_he_he.hent_hek == hek);
2365 if (he->shared_he_he.he_valu.hent_refcount - 1) {
2366 --he->shared_he_he.he_valu.hent_refcount;
2370 hash = HEK_HASH(hek);
2371 } else if (len < 0) {
2372 STRLEN tmplen = -len;
2374 /* See the note in hv_fetch(). --jhi */
2375 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
2378 k_flags = HVhek_UTF8;
2380 k_flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
2383 /* what follows was the moral equivalent of:
2384 if ((Svp = hv_fetch(PL_strtab, tmpsv, FALSE, hash))) {
2386 hv_delete(PL_strtab, str, len, G_DISCARD, hash);
2388 xhv = (XPVHV*)SvANY(PL_strtab);
2389 /* assert(xhv_array != 0) */
2390 first = oentry = &(HvARRAY(PL_strtab))[hash & (I32) HvMAX(PL_strtab)];
2392 const HE *const he_he = &(he->shared_he_he);
2393 for (entry = *oentry; entry; oentry = &HeNEXT(entry), entry = *oentry) {
2398 const int flags_masked = k_flags & HVhek_MASK;
2399 for (entry = *oentry; entry; oentry = &HeNEXT(entry), entry = *oentry) {
2400 if (HeHASH(entry) != hash) /* strings can't be equal */
2402 if (HeKLEN(entry) != len)
2404 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
2406 if (HeKFLAGS(entry) != flags_masked)
2413 if (--entry->he_valu.hent_refcount == 0) {
2414 *oentry = HeNEXT(entry);
2416 xhv->xhv_keys--; /* HvTOTALKEYS(hv)-- */
2421 Perl_ck_warner_d(aTHX_ packWARN(WARN_INTERNAL),
2422 "Attempt to free non-existent shared string '%s'%s"
2424 hek ? HEK_KEY(hek) : str,
2425 ((k_flags & HVhek_UTF8) ? " (utf8)" : "") pTHX__VALUE);
2426 if (k_flags & HVhek_FREEKEY)
2430 /* get a (constant) string ptr from the global string table
2431 * string will get added if it is not already there.
2432 * len and hash must both be valid for str.
2435 Perl_share_hek(pTHX_ const char *str, I32 len, register U32 hash)
2437 bool is_utf8 = FALSE;
2439 const char * const save = str;
2441 PERL_ARGS_ASSERT_SHARE_HEK;
2444 STRLEN tmplen = -len;
2446 /* See the note in hv_fetch(). --jhi */
2447 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
2449 /* If we were able to downgrade here, then than means that we were passed
2450 in a key which only had chars 0-255, but was utf8 encoded. */
2453 /* If we found we were able to downgrade the string to bytes, then
2454 we should flag that it needs upgrading on keys or each. Also flag
2455 that we need share_hek_flags to free the string. */
2457 flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
2460 return share_hek_flags (str, len, hash, flags);
2464 S_share_hek_flags(pTHX_ const char *str, I32 len, register U32 hash, int flags)
2468 const int flags_masked = flags & HVhek_MASK;
2469 const U32 hindex = hash & (I32) HvMAX(PL_strtab);
2470 register XPVHV * const xhv = (XPVHV*)SvANY(PL_strtab);
2472 PERL_ARGS_ASSERT_SHARE_HEK_FLAGS;
2474 /* what follows is the moral equivalent of:
2476 if (!(Svp = hv_fetch(PL_strtab, str, len, FALSE)))
2477 hv_store(PL_strtab, str, len, NULL, hash);
2479 Can't rehash the shared string table, so not sure if it's worth
2480 counting the number of entries in the linked list
2483 /* assert(xhv_array != 0) */
2484 entry = (HvARRAY(PL_strtab))[hindex];
2485 for (;entry; entry = HeNEXT(entry)) {
2486 if (HeHASH(entry) != hash) /* strings can't be equal */
2488 if (HeKLEN(entry) != len)
2490 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
2492 if (HeKFLAGS(entry) != flags_masked)
2498 /* What used to be head of the list.
2499 If this is NULL, then we're the first entry for this slot, which
2500 means we need to increate fill. */
2501 struct shared_he *new_entry;
2504 HE **const head = &HvARRAY(PL_strtab)[hindex];
2505 HE *const next = *head;
2507 /* We don't actually store a HE from the arena and a regular HEK.
2508 Instead we allocate one chunk of memory big enough for both,
2509 and put the HEK straight after the HE. This way we can find the
2510 HEK directly from the HE.
2513 Newx(k, STRUCT_OFFSET(struct shared_he,
2514 shared_he_hek.hek_key[0]) + len + 2, char);
2515 new_entry = (struct shared_he *)k;
2516 entry = &(new_entry->shared_he_he);
2517 hek = &(new_entry->shared_he_hek);
2519 Copy(str, HEK_KEY(hek), len, char);
2520 HEK_KEY(hek)[len] = 0;
2522 HEK_HASH(hek) = hash;
2523 HEK_FLAGS(hek) = (unsigned char)flags_masked;
2525 /* Still "point" to the HEK, so that other code need not know what
2527 HeKEY_hek(entry) = hek;
2528 entry->he_valu.hent_refcount = 0;
2529 HeNEXT(entry) = next;
2532 xhv->xhv_keys++; /* HvTOTALKEYS(hv)++ */
2533 if (!next) { /* initial entry? */
2534 } else if (xhv->xhv_keys > xhv->xhv_max /* HvKEYS(hv) > HvMAX(hv) */) {
2539 ++entry->he_valu.hent_refcount;
2541 if (flags & HVhek_FREEKEY)
2544 return HeKEY_hek(entry);
2548 Perl_hv_placeholders_p(pTHX_ HV *hv)
2551 MAGIC *mg = mg_find((const SV *)hv, PERL_MAGIC_rhash);
2553 PERL_ARGS_ASSERT_HV_PLACEHOLDERS_P;
2556 mg = sv_magicext(MUTABLE_SV(hv), 0, PERL_MAGIC_rhash, 0, 0, 0);
2559 Perl_die(aTHX_ "panic: hv_placeholders_p");
2562 return &(mg->mg_len);
2567 Perl_hv_placeholders_get(pTHX_ const HV *hv)
2570 MAGIC * const mg = mg_find((const SV *)hv, PERL_MAGIC_rhash);
2572 PERL_ARGS_ASSERT_HV_PLACEHOLDERS_GET;
2574 return mg ? mg->mg_len : 0;
2578 Perl_hv_placeholders_set(pTHX_ HV *hv, I32 ph)
2581 MAGIC * const mg = mg_find((const SV *)hv, PERL_MAGIC_rhash);
2583 PERL_ARGS_ASSERT_HV_PLACEHOLDERS_SET;
2588 if (!sv_magicext(MUTABLE_SV(hv), 0, PERL_MAGIC_rhash, 0, 0, ph))
2589 Perl_die(aTHX_ "panic: hv_placeholders_set");
2591 /* else we don't need to add magic to record 0 placeholders. */
2595 S_refcounted_he_value(pTHX_ const struct refcounted_he *he)
2600 PERL_ARGS_ASSERT_REFCOUNTED_HE_VALUE;
2602 switch(he->refcounted_he_data[0] & HVrhek_typemask) {
2607 value = &PL_sv_placeholder;
2610 value = newSViv(he->refcounted_he_val.refcounted_he_u_iv);
2613 value = newSVuv(he->refcounted_he_val.refcounted_he_u_uv);
2616 case HVrhek_PV_UTF8:
2617 /* Create a string SV that directly points to the bytes in our
2619 value = newSV_type(SVt_PV);
2620 SvPV_set(value, (char *) he->refcounted_he_data + 1);
2621 SvCUR_set(value, he->refcounted_he_val.refcounted_he_u_len);
2622 /* This stops anything trying to free it */
2623 SvLEN_set(value, 0);
2625 SvREADONLY_on(value);
2626 if ((he->refcounted_he_data[0] & HVrhek_typemask) == HVrhek_PV_UTF8)
2630 Perl_croak(aTHX_ "panic: refcounted_he_value bad flags %"UVxf,
2631 (UV)he->refcounted_he_data[0]);
2637 =for apidoc m|HV *|refcounted_he_chain_2hv|const struct refcounted_he *c|U32 flags
2639 Generates and returns a C<HV *> representing the content of a
2640 C<refcounted_he> chain.
2641 I<flags> is currently unused and must be zero.
2646 Perl_refcounted_he_chain_2hv(pTHX_ const struct refcounted_he *chain, U32 flags)
2650 U32 placeholders, max;
2653 Perl_croak(aTHX_ "panic: refcounted_he_chain_2hv bad flags %"UVxf,
2656 /* We could chase the chain once to get an idea of the number of keys,
2657 and call ksplit. But for now we'll make a potentially inefficient
2658 hash with only 8 entries in its array. */
2663 Newxz(array, PERL_HV_ARRAY_ALLOC_BYTES(max + 1), char);
2664 HvARRAY(hv) = (HE**)array;
2670 U32 hash = chain->refcounted_he_hash;
2672 U32 hash = HEK_HASH(chain->refcounted_he_hek);
2674 HE **oentry = &((HvARRAY(hv))[hash & max]);
2675 HE *entry = *oentry;
2678 for (; entry; entry = HeNEXT(entry)) {
2679 if (HeHASH(entry) == hash) {
2680 /* We might have a duplicate key here. If so, entry is older
2681 than the key we've already put in the hash, so if they are
2682 the same, skip adding entry. */
2684 const STRLEN klen = HeKLEN(entry);
2685 const char *const key = HeKEY(entry);
2686 if (klen == chain->refcounted_he_keylen
2687 && (!!HeKUTF8(entry)
2688 == !!(chain->refcounted_he_data[0] & HVhek_UTF8))
2689 && memEQ(key, REF_HE_KEY(chain), klen))
2692 if (HeKEY_hek(entry) == chain->refcounted_he_hek)
2694 if (HeKLEN(entry) == HEK_LEN(chain->refcounted_he_hek)
2695 && HeKUTF8(entry) == HEK_UTF8(chain->refcounted_he_hek)
2696 && memEQ(HeKEY(entry), HEK_KEY(chain->refcounted_he_hek),
2707 = share_hek_flags(REF_HE_KEY(chain),
2708 chain->refcounted_he_keylen,
2709 chain->refcounted_he_hash,
2710 (chain->refcounted_he_data[0]
2711 & (HVhek_UTF8|HVhek_WASUTF8)));
2713 HeKEY_hek(entry) = share_hek_hek(chain->refcounted_he_hek);
2715 value = refcounted_he_value(chain);
2716 if (value == &PL_sv_placeholder)
2718 HeVAL(entry) = value;
2720 /* Link it into the chain. */
2721 HeNEXT(entry) = *oentry;
2727 chain = chain->refcounted_he_next;
2731 clear_placeholders(hv, placeholders);
2732 HvTOTALKEYS(hv) -= placeholders;
2735 /* We could check in the loop to see if we encounter any keys with key
2736 flags, but it's probably not worth it, as this per-hash flag is only
2737 really meant as an optimisation for things like Storable. */
2739 DEBUG_A(Perl_hv_assert(aTHX_ hv));
2745 =for apidoc m|SV *|refcounted_he_fetch_pvn|const struct refcounted_he *chain|const char *keypv|STRLEN keylen|U32 hash|U32 flags
2747 Search along a C<refcounted_he> chain for an entry with the key specified
2748 by I<keypv> and I<keylen>. If I<flags> has the C<REFCOUNTED_HE_KEY_UTF8>
2749 bit set, the key octets are interpreted as UTF-8, otherwise they
2750 are interpreted as Latin-1. I<hash> is a precomputed hash of the key
2751 string, or zero if it has not been precomputed. Returns a mortal scalar
2752 representing the value associated with the key, or C<&PL_sv_placeholder>
2753 if there is no value associated with the key.
2759 Perl_refcounted_he_fetch_pvn(pTHX_ const struct refcounted_he *chain,
2760 const char *keypv, STRLEN keylen, U32 hash, U32 flags)
2764 PERL_ARGS_ASSERT_REFCOUNTED_HE_FETCH_PVN;
2766 if (flags & ~REFCOUNTED_HE_KEY_UTF8)
2767 Perl_croak(aTHX_ "panic: refcounted_he_fetch_pvn bad flags %"UVxf,
2770 return &PL_sv_placeholder;
2771 if (flags & REFCOUNTED_HE_KEY_UTF8) {
2772 /* For searching purposes, canonicalise to Latin-1 where possible. */
2773 const char *keyend = keypv + keylen, *p;
2774 STRLEN nonascii_count = 0;
2775 for (p = keypv; p != keyend; p++) {
2778 if (!((c & 0xfe) == 0xc2 && ++p != keyend &&
2779 (((U8)*p) & 0xc0) == 0x80))
2780 goto canonicalised_key;
2784 if (nonascii_count) {
2786 const char *p = keypv, *keyend = keypv + keylen;
2787 keylen -= nonascii_count;
2788 Newx(q, keylen, char);
2791 for (; p != keyend; p++, q++) {
2794 ((c & 0x80) ? ((c & 0x03) << 6) | (((U8)*++p) & 0x3f) : c);
2797 flags &= ~REFCOUNTED_HE_KEY_UTF8;
2798 canonicalised_key: ;
2800 utf8_flag = (flags & REFCOUNTED_HE_KEY_UTF8) ? HVhek_UTF8 : 0;
2802 PERL_HASH(hash, keypv, keylen);
2804 for (; chain; chain = chain->refcounted_he_next) {
2807 hash == chain->refcounted_he_hash &&
2808 keylen == chain->refcounted_he_keylen &&
2809 memEQ(REF_HE_KEY(chain), keypv, keylen) &&
2810 utf8_flag == (chain->refcounted_he_data[0] & HVhek_UTF8)
2812 hash == HEK_HASH(chain->refcounted_he_hek) &&
2813 keylen == (STRLEN)HEK_LEN(chain->refcounted_he_hek) &&
2814 memEQ(HEK_KEY(chain->refcounted_he_hek), keypv, keylen) &&
2815 utf8_flag == (HEK_FLAGS(chain->refcounted_he_hek) & HVhek_UTF8)
2818 return sv_2mortal(refcounted_he_value(chain));
2820 return &PL_sv_placeholder;
2824 =for apidoc m|SV *|refcounted_he_fetch_pv|const struct refcounted_he *chain|const char *key|U32 hash|U32 flags
2826 Like L</refcounted_he_fetch_pvn>, but takes a nul-terminated string
2827 instead of a string/length pair.
2833 Perl_refcounted_he_fetch_pv(pTHX_ const struct refcounted_he *chain,
2834 const char *key, U32 hash, U32 flags)
2836 PERL_ARGS_ASSERT_REFCOUNTED_HE_FETCH_PV;
2837 return refcounted_he_fetch_pvn(chain, key, strlen(key), hash, flags);
2841 =for apidoc m|SV *|refcounted_he_fetch_sv|const struct refcounted_he *chain|SV *key|U32 hash|U32 flags
2843 Like L</refcounted_he_fetch_pvn>, but takes a Perl scalar instead of a
2850 Perl_refcounted_he_fetch_sv(pTHX_ const struct refcounted_he *chain,
2851 SV *key, U32 hash, U32 flags)
2855 PERL_ARGS_ASSERT_REFCOUNTED_HE_FETCH_SV;
2856 if (flags & REFCOUNTED_HE_KEY_UTF8)
2857 Perl_croak(aTHX_ "panic: refcounted_he_fetch_sv bad flags %"UVxf,
2859 keypv = SvPV_const(key, keylen);
2861 flags |= REFCOUNTED_HE_KEY_UTF8;
2862 if (!hash && SvIsCOW_shared_hash(key))
2863 hash = SvSHARED_HASH(key);
2864 return refcounted_he_fetch_pvn(chain, keypv, keylen, hash, flags);
2868 =for apidoc m|struct refcounted_he *|refcounted_he_new_pvn|struct refcounted_he *parent|const char *keypv|STRLEN keylen|U32 hash|SV *value|U32 flags
2870 Creates a new C<refcounted_he>. This consists of a single key/value
2871 pair and a reference to an existing C<refcounted_he> chain (which may
2872 be empty), and thus forms a longer chain. When using the longer chain,
2873 the new key/value pair takes precedence over any entry for the same key
2874 further along the chain.
2876 The new key is specified by I<keypv> and I<keylen>. If I<flags> has
2877 the C<REFCOUNTED_HE_KEY_UTF8> bit set, the key octets are interpreted
2878 as UTF-8, otherwise they are interpreted as Latin-1. I<hash> is
2879 a precomputed hash of the key string, or zero if it has not been
2882 I<value> is the scalar value to store for this key. I<value> is copied
2883 by this function, which thus does not take ownership of any reference
2884 to it, and later changes to the scalar will not be reflected in the
2885 value visible in the C<refcounted_he>. Complex types of scalar will not
2886 be stored with referential integrity, but will be coerced to strings.
2887 I<value> may be either null or C<&PL_sv_placeholder> to indicate that no
2888 value is to be associated with the key; this, as with any non-null value,
2889 takes precedence over the existence of a value for the key further along
2892 I<parent> points to the rest of the C<refcounted_he> chain to be
2893 attached to the new C<refcounted_he>. This function takes ownership
2894 of one reference to I<parent>, and returns one reference to the new
2900 struct refcounted_he *
2901 Perl_refcounted_he_new_pvn(pTHX_ struct refcounted_he *parent,
2902 const char *keypv, STRLEN keylen, U32 hash, SV *value, U32 flags)
2905 STRLEN value_len = 0;
2906 const char *value_p = NULL;
2910 STRLEN key_offset = 1;
2911 struct refcounted_he *he;
2912 PERL_ARGS_ASSERT_REFCOUNTED_HE_NEW_PVN;
2914 if (!value || value == &PL_sv_placeholder) {
2915 value_type = HVrhek_delete;
2916 } else if (SvPOK(value)) {
2917 value_type = HVrhek_PV;
2918 } else if (SvIOK(value)) {
2919 value_type = SvUOK((const SV *)value) ? HVrhek_UV : HVrhek_IV;
2920 } else if (!SvOK(value)) {
2921 value_type = HVrhek_undef;
2923 value_type = HVrhek_PV;
2925 is_pv = value_type == HVrhek_PV;
2927 /* Do it this way so that the SvUTF8() test is after the SvPV, in case
2928 the value is overloaded, and doesn't yet have the UTF-8flag set. */
2929 value_p = SvPV_const(value, value_len);
2931 value_type = HVrhek_PV_UTF8;
2932 key_offset = value_len + 2;
2934 hekflags = value_type;
2936 if (flags & REFCOUNTED_HE_KEY_UTF8) {
2937 /* Canonicalise to Latin-1 where possible. */
2938 const char *keyend = keypv + keylen, *p;
2939 STRLEN nonascii_count = 0;
2940 for (p = keypv; p != keyend; p++) {
2943 if (!((c & 0xfe) == 0xc2 && ++p != keyend &&
2944 (((U8)*p) & 0xc0) == 0x80))
2945 goto canonicalised_key;
2949 if (nonascii_count) {
2951 const char *p = keypv, *keyend = keypv + keylen;
2952 keylen -= nonascii_count;
2953 Newx(q, keylen, char);
2956 for (; p != keyend; p++, q++) {
2959 ((c & 0x80) ? ((c & 0x03) << 6) | (((U8)*++p) & 0x3f) : c);
2962 flags &= ~REFCOUNTED_HE_KEY_UTF8;
2963 canonicalised_key: ;
2965 if (flags & REFCOUNTED_HE_KEY_UTF8)
2966 hekflags |= HVhek_UTF8;
2968 PERL_HASH(hash, keypv, keylen);
2970 he = (struct refcounted_he*)
2971 PerlMemShared_malloc(sizeof(struct refcounted_he) - 1
2977 he->refcounted_he_next = parent;
2980 Copy(value_p, he->refcounted_he_data + 1, value_len + 1, char);
2981 he->refcounted_he_val.refcounted_he_u_len = value_len;
2982 } else if (value_type == HVrhek_IV) {
2983 he->refcounted_he_val.refcounted_he_u_iv = SvIVX(value);
2984 } else if (value_type == HVrhek_UV) {
2985 he->refcounted_he_val.refcounted_he_u_uv = SvUVX(value);
2989 he->refcounted_he_hash = hash;
2990 he->refcounted_he_keylen = keylen;
2991 Copy(keypv, he->refcounted_he_data + key_offset, keylen, char);
2993 he->refcounted_he_hek = share_hek_flags(keypv, keylen, hash, hekflags);
2996 he->refcounted_he_data[0] = hekflags;
2997 he->refcounted_he_refcnt = 1;
3003 =for apidoc m|struct refcounted_he *|refcounted_he_new_pv|struct refcounted_he *parent|const char *key|U32 hash|SV *value|U32 flags
3005 Like L</refcounted_he_new_pvn>, but takes a nul-terminated string instead
3006 of a string/length pair.
3011 struct refcounted_he *
3012 Perl_refcounted_he_new_pv(pTHX_ struct refcounted_he *parent,
3013 const char *key, U32 hash, SV *value, U32 flags)
3015 PERL_ARGS_ASSERT_REFCOUNTED_HE_NEW_PV;
3016 return refcounted_he_new_pvn(parent, key, strlen(key), hash, value, flags);
3020 =for apidoc m|struct refcounted_he *|refcounted_he_new_sv|struct refcounted_he *parent|SV *key|U32 hash|SV *value|U32 flags
3022 Like L</refcounted_he_new_pvn>, but takes a Perl scalar instead of a
3028 struct refcounted_he *
3029 Perl_refcounted_he_new_sv(pTHX_ struct refcounted_he *parent,
3030 SV *key, U32 hash, SV *value, U32 flags)
3034 PERL_ARGS_ASSERT_REFCOUNTED_HE_NEW_SV;
3035 if (flags & REFCOUNTED_HE_KEY_UTF8)
3036 Perl_croak(aTHX_ "panic: refcounted_he_new_sv bad flags %"UVxf,
3038 keypv = SvPV_const(key, keylen);
3040 flags |= REFCOUNTED_HE_KEY_UTF8;
3041 if (!hash && SvIsCOW_shared_hash(key))
3042 hash = SvSHARED_HASH(key);
3043 return refcounted_he_new_pvn(parent, keypv, keylen, hash, value, flags);
3047 =for apidoc m|void|refcounted_he_free|struct refcounted_he *he
3049 Decrements the reference count of a C<refcounted_he> by one. If the
3050 reference count reaches zero the structure's memory is freed, which
3051 (recursively) causes a reduction of its parent C<refcounted_he>'s
3052 reference count. It is safe to pass a null pointer to this function:
3053 no action occurs in this case.
3059 Perl_refcounted_he_free(pTHX_ struct refcounted_he *he) {
3061 PERL_UNUSED_CONTEXT;
3064 struct refcounted_he *copy;
3068 new_count = --he->refcounted_he_refcnt;
3069 HINTS_REFCNT_UNLOCK;
3075 #ifndef USE_ITHREADS
3076 unshare_hek_or_pvn (he->refcounted_he_hek, 0, 0, 0);
3079 he = he->refcounted_he_next;
3080 PerlMemShared_free(copy);
3085 =for apidoc m|struct refcounted_he *|refcounted_he_inc|struct refcounted_he *he
3087 Increment the reference count of a C<refcounted_he>. The pointer to the
3088 C<refcounted_he> is also returned. It is safe to pass a null pointer
3089 to this function: no action occurs and a null pointer is returned.
3094 struct refcounted_he *
3095 Perl_refcounted_he_inc(pTHX_ struct refcounted_he *he)
3099 he->refcounted_he_refcnt++;
3100 HINTS_REFCNT_UNLOCK;
3105 /* pp_entereval is aware that labels are stored with a key ':' at the top of
3108 Perl_fetch_cop_label(pTHX_ COP *const cop, STRLEN *len, U32 *flags) {
3109 struct refcounted_he *const chain = cop->cop_hints_hash;
3111 PERL_ARGS_ASSERT_FETCH_COP_LABEL;
3116 if (chain->refcounted_he_keylen != 1)
3118 if (*REF_HE_KEY(chain) != ':')
3121 if ((STRLEN)HEK_LEN(chain->refcounted_he_hek) != 1)
3123 if (*HEK_KEY(chain->refcounted_he_hek) != ':')
3126 /* Stop anyone trying to really mess us up by adding their own value for
3128 if ((chain->refcounted_he_data[0] & HVrhek_typemask) != HVrhek_PV
3129 && (chain->refcounted_he_data[0] & HVrhek_typemask) != HVrhek_PV_UTF8)
3133 *len = chain->refcounted_he_val.refcounted_he_u_len;
3135 *flags = ((chain->refcounted_he_data[0] & HVrhek_typemask)
3136 == HVrhek_PV_UTF8) ? SVf_UTF8 : 0;
3138 return chain->refcounted_he_data + 1;
3142 Perl_store_cop_label(pTHX_ COP *const cop, const char *label, STRLEN len,
3146 PERL_ARGS_ASSERT_STORE_COP_LABEL;
3148 if (flags & ~(SVf_UTF8))
3149 Perl_croak(aTHX_ "panic: store_cop_label illegal flag bits 0x%" UVxf,
3151 labelsv = sv_2mortal(newSVpvn(label, len));
3152 if (flags & SVf_UTF8)
3155 = refcounted_he_new_pvs(cop->cop_hints_hash, ":", labelsv, 0);
3159 =for apidoc hv_assert
3161 Check that a hash is in an internally consistent state.
3169 Perl_hv_assert(pTHX_ HV *hv)
3174 int placeholders = 0;
3177 const I32 riter = HvRITER_get(hv);
3178 HE *eiter = HvEITER_get(hv);
3180 PERL_ARGS_ASSERT_HV_ASSERT;
3182 (void)hv_iterinit(hv);
3184 while ((entry = hv_iternext_flags(hv, HV_ITERNEXT_WANTPLACEHOLDERS))) {
3185 /* sanity check the values */
3186 if (HeVAL(entry) == &PL_sv_placeholder)
3190 /* sanity check the keys */
3191 if (HeSVKEY(entry)) {
3192 NOOP; /* Don't know what to check on SV keys. */
3193 } else if (HeKUTF8(entry)) {
3195 if (HeKWASUTF8(entry)) {
3196 PerlIO_printf(Perl_debug_log,
3197 "hash key has both WASUTF8 and UTF8: '%.*s'\n",
3198 (int) HeKLEN(entry), HeKEY(entry));
3201 } else if (HeKWASUTF8(entry))
3204 if (!SvTIED_mg((const SV *)hv, PERL_MAGIC_tied)) {
3205 static const char bad_count[] = "Count %d %s(s), but hash reports %d\n";
3206 const int nhashkeys = HvUSEDKEYS(hv);
3207 const int nhashplaceholders = HvPLACEHOLDERS_get(hv);
3209 if (nhashkeys != real) {
3210 PerlIO_printf(Perl_debug_log, bad_count, real, "keys", nhashkeys );
3213 if (nhashplaceholders != placeholders) {
3214 PerlIO_printf(Perl_debug_log, bad_count, placeholders, "placeholder", nhashplaceholders );
3218 if (withflags && ! HvHASKFLAGS(hv)) {
3219 PerlIO_printf(Perl_debug_log,
3220 "Hash has HASKFLAGS off but I count %d key(s) with flags\n",
3225 sv_dump(MUTABLE_SV(hv));
3227 HvRITER_set(hv, riter); /* Restore hash iterator state */
3228 HvEITER_set(hv, eiter);
3235 * c-indentation-style: bsd
3237 * indent-tabs-mode: t
3240 * ex: set ts=8 sts=4 sw=4 noet: