3 * Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
4 * 2000, 2001, 2002, 2003, 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 of all that I have seen." --Bilbo
16 =head1 Hash Manipulation Functions
21 #define PERL_HASH_INTERNAL_ACCESS
24 #define HV_MAX_LENGTH_BEFORE_SPLIT 14
34 PL_he_root = HeNEXT(he);
43 HeNEXT(p) = (HE*)PL_he_root;
54 New(54, ptr, 1008/sizeof(XPV), XPV);
55 ptr->xpv_pv = (char*)PL_he_arenaroot;
56 PL_he_arenaroot = ptr;
59 heend = &he[1008 / sizeof(HE) - 1];
62 HeNEXT(he) = (HE*)(he + 1);
70 #define new_HE() (HE*)safemalloc(sizeof(HE))
71 #define del_HE(p) safefree((char*)p)
75 #define new_HE() new_he()
76 #define del_HE(p) del_he(p)
81 S_save_hek_flags(pTHX_ const char *str, I32 len, U32 hash, int flags)
86 New(54, k, HEK_BASESIZE + len + 2, char);
88 Copy(str, HEK_KEY(hek), len, char);
89 HEK_KEY(hek)[len] = 0;
92 HEK_FLAGS(hek) = (unsigned char)flags;
96 /* free the pool of temporary HE/HEK pairs retunrned by hv_fetch_ent
100 Perl_free_tied_hv_pool(pTHX)
103 HE *he = PL_hv_fetch_ent_mh;
105 Safefree(HeKEY_hek(he));
110 PL_hv_fetch_ent_mh = Nullhe;
113 #if defined(USE_ITHREADS)
115 Perl_he_dup(pTHX_ HE *e, bool shared, CLONE_PARAMS* param)
121 /* look for it in the table first */
122 ret = (HE*)ptr_table_fetch(PL_ptr_table, e);
126 /* create anew and remember what it is */
128 ptr_table_store(PL_ptr_table, e, ret);
130 HeNEXT(ret) = he_dup(HeNEXT(e),shared, param);
131 if (HeKLEN(e) == HEf_SVKEY) {
133 New(54, k, HEK_BASESIZE + sizeof(SV*), char);
134 HeKEY_hek(ret) = (HEK*)k;
135 HeKEY_sv(ret) = SvREFCNT_inc(sv_dup(HeKEY_sv(e), param));
138 HeKEY_hek(ret) = share_hek_flags(HeKEY(e), HeKLEN(e), HeHASH(e),
141 HeKEY_hek(ret) = save_hek_flags(HeKEY(e), HeKLEN(e), HeHASH(e),
143 HeVAL(ret) = SvREFCNT_inc(sv_dup(HeVAL(e), param));
146 #endif /* USE_ITHREADS */
149 S_hv_notallowed(pTHX_ int flags, const char *key, I32 klen,
152 SV *sv = sv_newmortal(), *esv = sv_newmortal();
153 if (!(flags & HVhek_FREEKEY)) {
154 sv_setpvn(sv, key, klen);
157 /* Need to free saved eventually assign to mortal SV */
158 /* XXX is this line an error ???: SV *sv = sv_newmortal(); */
159 sv_usepvn(sv, (char *) key, klen);
161 if (flags & HVhek_UTF8) {
164 Perl_sv_setpvf(aTHX_ esv, "Attempt to %s a restricted hash", msg);
165 Perl_croak(aTHX_ SvPVX(esv), sv);
168 /* (klen == HEf_SVKEY) is special for MAGICAL hv entries, meaning key slot
174 Returns the SV which corresponds to the specified key in the hash. The
175 C<klen> is the length of the key. If C<lval> is set then the fetch will be
176 part of a store. Check that the return value is non-null before
177 dereferencing it to an C<SV*>.
179 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
180 information on how to use this function on tied hashes.
187 Perl_hv_fetch(pTHX_ HV *hv, const char *key, I32 klen, I32 lval)
189 bool is_utf8 = FALSE;
190 const char *keysave = key;
199 STRLEN tmplen = klen;
200 /* Just casting the &klen to (STRLEN) won't work well
201 * if STRLEN and I32 are of different widths. --jhi */
202 key = (char*)bytes_from_utf8((U8*)key, &tmplen, &is_utf8);
204 /* If we were able to downgrade here, then than means that we were
205 passed in a key which only had chars 0-255, but was utf8 encoded. */
208 /* If we found we were able to downgrade the string to bytes, then
209 we should flag that it needs upgrading on keys or each. */
211 flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
214 return hv_fetch_flags (hv, key, klen, lval, flags);
218 S_hv_fetch_flags(pTHX_ HV *hv, const char *key, I32 klen, I32 lval, int flags)
228 if (SvRMAGICAL(hv)) {
229 if (mg_find((SV*)hv, PERL_MAGIC_tied) || SvGMAGICAL((SV*)hv)) {
231 sv_upgrade(sv, SVt_PVLV);
232 if (flags & HVhek_UTF8) {
233 /* This hack based on the code in hv_exists_ent seems to be
234 the easiest way to pass the utf8 flag through and fix
235 the bug in hv_exists for tied hashes with utf8 keys. */
236 SV *keysv = sv_2mortal(newSVpvn(key, klen));
238 mg_copy((SV*)hv, sv, (char *)keysv, HEf_SVKEY);
240 mg_copy((SV*)hv, sv, key, klen);
242 if (flags & HVhek_FREEKEY)
245 LvTARG(sv) = sv; /* fake (SV**) */
246 return &(LvTARG(sv));
248 #ifdef ENV_IS_CASELESS
249 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
251 for (i = 0; i < klen; ++i)
252 if (isLOWER(key[i])) {
253 char *nkey = strupr(SvPVX(sv_2mortal(newSVpvn(key,klen))));
254 SV **ret = hv_fetch(hv, nkey, klen, 0);
256 ret = hv_store_flags(hv, key, klen, NEWSV(61,0), 0,
258 } else if (flags & HVhek_FREEKEY)
266 /* We use xhv->xhv_foo fields directly instead of HvFOO(hv) to
267 avoid unnecessary pointer dereferencing. */
268 xhv = (XPVHV*)SvANY(hv);
269 if (!xhv->xhv_array /* !HvARRAY(hv) */) {
271 #ifdef DYNAMIC_ENV_FETCH /* if it's an %ENV lookup, we may get it on the fly */
272 || (SvRMAGICAL((SV*)hv) && mg_find((SV*)hv, PERL_MAGIC_env))
275 Newz(503, xhv->xhv_array /* HvARRAY(hv) */,
276 PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */),
279 if (flags & HVhek_FREEKEY)
286 PERL_HASH_INTERNAL(hash, key, klen);
287 /* Yes, you do need this even though you are not "storing" because
288 you can flip the flags below if doing an lval lookup. (And that
289 was put in to give the semantics Andreas was expecting.) */
290 flags |= HVhek_REHASH;
292 PERL_HASH(hash, key, klen);
295 /* entry = (HvARRAY(hv))[hash & (I32) HvMAX(hv)]; */
296 entry = ((HE**)xhv->xhv_array)[hash & (I32) xhv->xhv_max];
297 for (; entry; entry = HeNEXT(entry)) {
298 if (!HeKEY_hek(entry))
300 if (HeHASH(entry) != hash) /* strings can't be equal */
302 if (HeKLEN(entry) != (I32)klen)
304 if (HeKEY(entry) != key && memNE(HeKEY(entry),key,klen)) /* is this it? */
306 /* flags is 0 if not utf8. need HeKFLAGS(entry) also 0.
307 flags is 1 if utf8. need HeKFLAGS(entry) also 1.
308 xor is true if bits differ, in which case this isn't a match. */
309 if ((HeKFLAGS(entry) ^ flags) & HVhek_UTF8)
311 if (lval && HeKFLAGS(entry) != flags) {
312 /* We match if HVhek_UTF8 bit in our flags and hash key's match.
313 But if entry was set previously with HVhek_WASUTF8 and key now
314 doesn't (or vice versa) then we should change the key's flag,
315 as this is assignment. */
316 if (HvSHAREKEYS(hv)) {
317 /* Need to swap the key we have for a key with the flags we
318 need. As keys are shared we can't just write to the flag,
319 so we share the new one, unshare the old one. */
320 int flags_nofree = flags & ~HVhek_FREEKEY;
321 HEK *new_hek = share_hek_flags(key, klen, hash, flags_nofree);
322 unshare_hek (HeKEY_hek(entry));
323 HeKEY_hek(entry) = new_hek;
326 HeKFLAGS(entry) = flags;
327 if (flags & HVhek_ENABLEHVKFLAGS)
330 if (flags & HVhek_FREEKEY)
332 /* if we find a placeholder, we pretend we haven't found anything */
333 if (HeVAL(entry) == &PL_sv_placeholder)
335 return &HeVAL(entry);
338 #ifdef DYNAMIC_ENV_FETCH /* %ENV lookup? If so, try to fetch the value now */
339 if (SvRMAGICAL((SV*)hv) && mg_find((SV*)hv, PERL_MAGIC_env)) {
341 char *env = PerlEnv_ENVgetenv_len(key,&len);
343 sv = newSVpvn(env,len);
345 if (flags & HVhek_FREEKEY)
347 return hv_store(hv,key,klen,sv,hash);
351 if (!entry && SvREADONLY(hv)) {
352 S_hv_notallowed(aTHX_ flags, key, klen,
353 "access disallowed key '%"SVf"' in"
356 if (lval) { /* gonna assign to this, so it better be there */
358 return hv_store_flags(hv,key,klen,sv,hash,flags);
360 if (flags & HVhek_FREEKEY)
365 /* returns an HE * structure with the all fields set */
366 /* note that hent_val will be a mortal sv for MAGICAL hashes */
368 =for apidoc hv_fetch_ent
370 Returns the hash entry which corresponds to the specified key in the hash.
371 C<hash> must be a valid precomputed hash number for the given C<key>, or 0
372 if you want the function to compute it. IF C<lval> is set then the fetch
373 will be part of a store. Make sure the return value is non-null before
374 accessing it. The return value when C<tb> is a tied hash is a pointer to a
375 static location, so be sure to make a copy of the structure if you need to
378 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
379 information on how to use this function on tied hashes.
385 Perl_hv_fetch_ent(pTHX_ HV *hv, SV *keysv, I32 lval, register U32 hash)
399 if (SvRMAGICAL(hv)) {
400 if (mg_find((SV*)hv, PERL_MAGIC_tied) || SvGMAGICAL((SV*)hv)) {
402 keysv = newSVsv(keysv);
403 mg_copy((SV*)hv, sv, (char*)keysv, HEf_SVKEY);
404 /* grab a fake HE/HEK pair from the pool or make a new one */
405 entry = PL_hv_fetch_ent_mh;
407 PL_hv_fetch_ent_mh = HeNEXT(entry);
411 New(54, k, HEK_BASESIZE + sizeof(SV*), char);
412 HeKEY_hek(entry) = (HEK*)k;
414 HeNEXT(entry) = Nullhe;
415 HeSVKEY_set(entry, keysv);
417 sv_upgrade(sv, SVt_PVLV);
419 LvTARG(sv) = (SV*)entry; /* so we can free entry when freeing sv */
422 #ifdef ENV_IS_CASELESS
423 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
425 key = SvPV(keysv, klen);
426 for (i = 0; i < klen; ++i)
427 if (isLOWER(key[i])) {
428 SV *nkeysv = sv_2mortal(newSVpvn(key,klen));
429 (void)strupr(SvPVX(nkeysv));
430 entry = hv_fetch_ent(hv, nkeysv, 0, 0);
432 entry = hv_store_ent(hv, keysv, NEWSV(61,0), hash);
439 keysave = key = SvPV(keysv, klen);
440 xhv = (XPVHV*)SvANY(hv);
441 if (!xhv->xhv_array /* !HvARRAY(hv) */) {
443 #ifdef DYNAMIC_ENV_FETCH /* if it's an %ENV lookup, we may get it on the fly */
444 || (SvRMAGICAL((SV*)hv) && mg_find((SV*)hv, PERL_MAGIC_env))
447 Newz(503, xhv->xhv_array /* HvARRAY(hv) */,
448 PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */),
454 is_utf8 = (SvUTF8(keysv)!=0);
457 key = (char*)bytes_from_utf8((U8*)key, &klen, &is_utf8);
461 flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
465 PERL_HASH_INTERNAL(hash, key, klen);
466 /* Yes, you do need this even though you are not "storing" because
467 you can flip the flags below if doing an lval lookup. (And that
468 was put in to give the semantics Andreas was expecting.) */
469 flags |= HVhek_REHASH;
471 if SvIsCOW_shared_hash(keysv) {
474 PERL_HASH(hash, key, klen);
478 /* entry = (HvARRAY(hv))[hash & (I32) HvMAX(hv)]; */
479 entry = ((HE**)xhv->xhv_array)[hash & (I32) xhv->xhv_max];
480 for (; entry; entry = HeNEXT(entry)) {
481 if (HeHASH(entry) != hash) /* strings can't be equal */
483 if (HeKLEN(entry) != (I32)klen)
485 if (HeKEY(entry) != key && memNE(HeKEY(entry),key,klen)) /* is this it? */
487 if ((HeKFLAGS(entry) ^ flags) & HVhek_UTF8)
489 if (lval && HeKFLAGS(entry) != flags) {
490 /* We match if HVhek_UTF8 bit in our flags and hash key's match.
491 But if entry was set previously with HVhek_WASUTF8 and key now
492 doesn't (or vice versa) then we should change the key's flag,
493 as this is assignment. */
494 if (HvSHAREKEYS(hv)) {
495 /* Need to swap the key we have for a key with the flags we
496 need. As keys are shared we can't just write to the flag,
497 so we share the new one, unshare the old one. */
498 int flags_nofree = flags & ~HVhek_FREEKEY;
499 HEK *new_hek = share_hek_flags(key, klen, hash, flags_nofree);
500 unshare_hek (HeKEY_hek(entry));
501 HeKEY_hek(entry) = new_hek;
504 HeKFLAGS(entry) = flags;
505 if (flags & HVhek_ENABLEHVKFLAGS)
510 /* if we find a placeholder, we pretend we haven't found anything */
511 if (HeVAL(entry) == &PL_sv_placeholder)
515 #ifdef DYNAMIC_ENV_FETCH /* %ENV lookup? If so, try to fetch the value now */
516 if (SvRMAGICAL((SV*)hv) && mg_find((SV*)hv, PERL_MAGIC_env)) {
518 char *env = PerlEnv_ENVgetenv_len(key,&len);
520 sv = newSVpvn(env,len);
522 return hv_store_ent(hv,keysv,sv,hash);
526 if (!entry && SvREADONLY(hv)) {
527 S_hv_notallowed(aTHX_ flags, key, klen,
528 "access disallowed key '%"SVf"' in"
531 if (flags & HVhek_FREEKEY)
533 if (lval) { /* gonna assign to this, so it better be there */
535 return hv_store_ent(hv,keysv,sv,hash);
541 S_hv_magic_check(pTHX_ HV *hv, bool *needs_copy, bool *needs_store)
543 MAGIC *mg = SvMAGIC(hv);
547 if (isUPPER(mg->mg_type)) {
549 switch (mg->mg_type) {
550 case PERL_MAGIC_tied:
552 *needs_store = FALSE;
555 mg = mg->mg_moremagic;
562 Stores an SV in a hash. The hash key is specified as C<key> and C<klen> is
563 the length of the key. The C<hash> parameter is the precomputed hash
564 value; if it is zero then Perl will compute it. The return value will be
565 NULL if the operation failed or if the value did not need to be actually
566 stored within the hash (as in the case of tied hashes). Otherwise it can
567 be dereferenced to get the original C<SV*>. Note that the caller is
568 responsible for suitably incrementing the reference count of C<val> before
569 the call, and decrementing it if the function returned NULL. Effectively
570 a successful hv_store takes ownership of one reference to C<val>. This is
571 usually what you want; a newly created SV has a reference count of one, so
572 if all your code does is create SVs then store them in a hash, hv_store
573 will own the only reference to the new SV, and your code doesn't need to do
574 anything further to tidy up. hv_store is not implemented as a call to
575 hv_store_ent, and does not create a temporary SV for the key, so if your
576 key data is not already in SV form then use hv_store in preference to
579 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
580 information on how to use this function on tied hashes.
586 Perl_hv_store(pTHX_ HV *hv, const char *key, I32 klen, SV *val, U32 hash)
588 bool is_utf8 = FALSE;
589 const char *keysave = key;
598 STRLEN tmplen = klen;
599 /* Just casting the &klen to (STRLEN) won't work well
600 * if STRLEN and I32 are of different widths. --jhi */
601 key = (char*)bytes_from_utf8((U8*)key, &tmplen, &is_utf8);
603 /* If we were able to downgrade here, then than means that we were
604 passed in a key which only had chars 0-255, but was utf8 encoded. */
607 /* If we found we were able to downgrade the string to bytes, then
608 we should flag that it needs upgrading on keys or each. */
610 flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
613 return hv_store_flags (hv, key, klen, val, hash, flags);
617 Perl_hv_store_flags(pTHX_ HV *hv, const char *key, I32 klen, SV *val,
618 register U32 hash, int flags)
621 register U32 n_links;
623 register HE **oentry;
628 xhv = (XPVHV*)SvANY(hv);
632 hv_magic_check (hv, &needs_copy, &needs_store);
634 if (flags & HVhek_UTF8) {
635 /* This hack based on the code in hv_exists_ent seems to be
636 the easiest way to pass the utf8 flag through and fix
637 the bug in hv_exists for tied hashes with utf8 keys. */
638 SV *keysv = sv_2mortal(newSVpvn(key, klen));
640 mg_copy((SV*)hv, val, (char *)keysv, HEf_SVKEY);
642 mg_copy((SV*)hv, val, key, klen);
644 if (!xhv->xhv_array /* !HvARRAY */ && !needs_store) {
645 if (flags & HVhek_FREEKEY)
649 #ifdef ENV_IS_CASELESS
650 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
651 key = savepvn(key,klen);
652 key = (const char*)strupr((char*)key);
660 HvHASKFLAGS_on((SV*)hv);
663 /* We don't have a pointer to the hv, so we have to replicate the
664 flag into every HEK, so that hv_iterkeysv can see it. */
665 flags |= HVhek_REHASH;
666 PERL_HASH_INTERNAL(hash, key, klen);
668 PERL_HASH(hash, key, klen);
670 if (!xhv->xhv_array /* !HvARRAY(hv) */)
671 Newz(505, xhv->xhv_array /* HvARRAY(hv) */,
672 PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */),
675 /* oentry = &(HvARRAY(hv))[hash & (I32) HvMAX(hv)]; */
676 oentry = &((HE**)xhv->xhv_array)[hash & (I32) xhv->xhv_max];
680 for (entry = *oentry; entry; ++n_links, entry = HeNEXT(entry)) {
681 if (HeHASH(entry) != hash) /* strings can't be equal */
683 if (HeKLEN(entry) != (I32)klen)
685 if (HeKEY(entry) != key && memNE(HeKEY(entry),key,klen)) /* is this it? */
687 if ((HeKFLAGS(entry) ^ flags) & HVhek_UTF8)
689 if (HeVAL(entry) == &PL_sv_placeholder)
690 xhv->xhv_placeholders--; /* yes, can store into placeholder slot */
692 SvREFCNT_dec(HeVAL(entry));
693 if (flags & HVhek_PLACEHOLD) {
694 /* We have been requested to insert a placeholder. Currently
695 only Storable is allowed to do this. */
696 xhv->xhv_placeholders++;
697 HeVAL(entry) = &PL_sv_placeholder;
701 if (HeKFLAGS(entry) != flags) {
702 /* We match if HVhek_UTF8 bit in our flags and hash key's match.
703 But if entry was set previously with HVhek_WASUTF8 and key now
704 doesn't (or vice versa) then we should change the key's flag,
705 as this is assignment. */
706 if (HvSHAREKEYS(hv)) {
707 /* Need to swap the key we have for a key with the flags we
708 need. As keys are shared we can't just write to the flag,
709 so we share the new one, unshare the old one. */
710 int flags_nofree = flags & ~HVhek_FREEKEY;
711 HEK *new_hek = share_hek_flags(key, klen, hash, flags_nofree);
712 unshare_hek (HeKEY_hek(entry));
713 HeKEY_hek(entry) = new_hek;
716 HeKFLAGS(entry) = flags;
718 if (flags & HVhek_FREEKEY)
720 return &HeVAL(entry);
723 if (SvREADONLY(hv)) {
724 S_hv_notallowed(aTHX_ flags, key, klen,
725 "access disallowed key '%"SVf"' to"
730 /* share_hek_flags will do the free for us. This might be considered
733 HeKEY_hek(entry) = share_hek_flags(key, klen, hash, flags);
734 else /* gotta do the real thing */
735 HeKEY_hek(entry) = save_hek_flags(key, klen, hash, flags);
736 if (flags & HVhek_PLACEHOLD) {
737 /* We have been requested to insert a placeholder. Currently
738 only Storable is allowed to do this. */
739 xhv->xhv_placeholders++;
740 HeVAL(entry) = &PL_sv_placeholder;
743 HeNEXT(entry) = *oentry;
746 xhv->xhv_keys++; /* HvKEYS(hv)++ */
747 if (!n_links) { /* initial entry? */
748 xhv->xhv_fill++; /* HvFILL(hv)++ */
749 } else if ((xhv->xhv_keys > (IV)xhv->xhv_max)
750 || ((n_links > HV_MAX_LENGTH_BEFORE_SPLIT) && !HvREHASH(hv))) {
751 /* Use the old HvKEYS(hv) > HvMAX(hv) condition to limit bucket
752 splits on a rehashed hash, as we're not going to split it again,
753 and if someone is lucky (evil) enough to get all the keys in one
754 list they could exhaust our memory as we repeatedly double the
755 number of buckets on every entry. Linear search feels a less worse
760 return &HeVAL(entry);
764 =for apidoc hv_store_ent
766 Stores C<val> in a hash. The hash key is specified as C<key>. The C<hash>
767 parameter is the precomputed hash value; if it is zero then Perl will
768 compute it. The return value is the new hash entry so created. It will be
769 NULL if the operation failed or if the value did not need to be actually
770 stored within the hash (as in the case of tied hashes). Otherwise the
771 contents of the return value can be accessed using the C<He?> macros
772 described here. Note that the caller is responsible for suitably
773 incrementing the reference count of C<val> before the call, and
774 decrementing it if the function returned NULL. Effectively a successful
775 hv_store_ent takes ownership of one reference to C<val>. This is
776 usually what you want; a newly created SV has a reference count of one, so
777 if all your code does is create SVs then store them in a hash, hv_store
778 will own the only reference to the new SV, and your code doesn't need to do
779 anything further to tidy up. Note that hv_store_ent only reads the C<key>;
780 unlike C<val> it does not take ownership of it, so maintaining the correct
781 reference count on C<key> is entirely the caller's responsibility. hv_store
782 is not implemented as a call to hv_store_ent, and does not create a temporary
783 SV for the key, so if your key data is not already in SV form then use
784 hv_store in preference to hv_store_ent.
786 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
787 information on how to use this function on tied hashes.
793 Perl_hv_store_ent(pTHX_ HV *hv, SV *keysv, SV *val, U32 hash)
808 xhv = (XPVHV*)SvANY(hv);
812 hv_magic_check (hv, &needs_copy, &needs_store);
814 bool save_taint = PL_tainted;
816 PL_tainted = SvTAINTED(keysv);
817 keysv = sv_2mortal(newSVsv(keysv));
818 mg_copy((SV*)hv, val, (char*)keysv, HEf_SVKEY);
819 TAINT_IF(save_taint);
820 if (!xhv->xhv_array /* !HvARRAY(hv) */ && !needs_store)
822 #ifdef ENV_IS_CASELESS
823 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
824 key = SvPV(keysv, klen);
825 keysv = sv_2mortal(newSVpvn(key,klen));
826 (void)strupr(SvPVX(keysv));
833 keysave = key = SvPV(keysv, klen);
834 is_utf8 = (SvUTF8(keysv) != 0);
837 key = (char*)bytes_from_utf8((U8*)key, &klen, &is_utf8);
841 flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
842 HvHASKFLAGS_on((SV*)hv);
846 /* We don't have a pointer to the hv, so we have to replicate the
847 flag into every HEK, so that hv_iterkeysv can see it. */
848 flags |= HVhek_REHASH;
849 PERL_HASH_INTERNAL(hash, key, klen);
851 if SvIsCOW_shared_hash(keysv) {
854 PERL_HASH(hash, key, klen);
858 if (!xhv->xhv_array /* !HvARRAY(hv) */)
859 Newz(505, xhv->xhv_array /* HvARRAY(hv) */,
860 PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */),
863 /* oentry = &(HvARRAY(hv))[hash & (I32) HvMAX(hv)]; */
864 oentry = &((HE**)xhv->xhv_array)[hash & (I32) xhv->xhv_max];
867 for (; entry; ++n_links, entry = HeNEXT(entry)) {
868 if (HeHASH(entry) != hash) /* strings can't be equal */
870 if (HeKLEN(entry) != (I32)klen)
872 if (HeKEY(entry) != key && memNE(HeKEY(entry),key,klen)) /* is this it? */
874 if ((HeKFLAGS(entry) ^ flags) & HVhek_UTF8)
876 if (HeVAL(entry) == &PL_sv_placeholder)
877 xhv->xhv_placeholders--; /* yes, can store into placeholder slot */
879 SvREFCNT_dec(HeVAL(entry));
881 if (HeKFLAGS(entry) != flags) {
882 /* We match if HVhek_UTF8 bit in our flags and hash key's match.
883 But if entry was set previously with HVhek_WASUTF8 and key now
884 doesn't (or vice versa) then we should change the key's flag,
885 as this is assignment. */
886 if (HvSHAREKEYS(hv)) {
887 /* Need to swap the key we have for a key with the flags we
888 need. As keys are shared we can't just write to the flag,
889 so we share the new one, unshare the old one. */
890 int flags_nofree = flags & ~HVhek_FREEKEY;
891 HEK *new_hek = share_hek_flags(key, klen, hash, flags_nofree);
892 unshare_hek (HeKEY_hek(entry));
893 HeKEY_hek(entry) = new_hek;
896 HeKFLAGS(entry) = flags;
898 if (flags & HVhek_FREEKEY)
903 if (SvREADONLY(hv)) {
904 S_hv_notallowed(aTHX_ flags, key, klen,
905 "access disallowed key '%"SVf"' to"
910 /* share_hek_flags will do the free for us. This might be considered
913 HeKEY_hek(entry) = share_hek_flags(key, klen, hash, flags);
914 else /* gotta do the real thing */
915 HeKEY_hek(entry) = save_hek_flags(key, klen, hash, flags);
917 HeNEXT(entry) = *oentry;
920 xhv->xhv_keys++; /* HvKEYS(hv)++ */
921 if (!n_links) { /* initial entry? */
922 xhv->xhv_fill++; /* HvFILL(hv)++ */
923 } else if ((xhv->xhv_keys > (IV)xhv->xhv_max)
924 || ((n_links > HV_MAX_LENGTH_BEFORE_SPLIT) && !HvREHASH(hv))) {
925 /* Use only the old HvKEYS(hv) > HvMAX(hv) condition to limit bucket
926 splits on a rehashed hash, as we're not going to split it again,
927 and if someone is lucky (evil) enough to get all the keys in one
928 list they could exhaust our memory as we repeatedly double the
929 number of buckets on every entry. Linear search feels a less worse
938 =for apidoc hv_delete
940 Deletes a key/value pair in the hash. The value SV is removed from the
941 hash and returned to the caller. The C<klen> is the length of the key.
942 The C<flags> value will normally be zero; if set to G_DISCARD then NULL
949 Perl_hv_delete(pTHX_ HV *hv, const char *key, I32 klen, I32 flags)
955 register HE **oentry;
958 bool is_utf8 = FALSE;
960 const char *keysave = key;
968 if (SvRMAGICAL(hv)) {
971 hv_magic_check (hv, &needs_copy, &needs_store);
974 && (svp = hv_fetch(hv, key, is_utf8 ? -klen : klen, TRUE))) {
980 if (mg_find(sv, PERL_MAGIC_tiedelem)) {
981 /* No longer an element */
982 sv_unmagic(sv, PERL_MAGIC_tiedelem);
985 return Nullsv; /* element cannot be deleted */
987 #ifdef ENV_IS_CASELESS
988 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
989 sv = sv_2mortal(newSVpvn(key,klen));
990 key = strupr(SvPVX(sv));
995 xhv = (XPVHV*)SvANY(hv);
996 if (!xhv->xhv_array /* !HvARRAY(hv) */)
1000 STRLEN tmplen = klen;
1001 /* See the note in hv_fetch(). --jhi */
1002 key = (char*)bytes_from_utf8((U8*)key, &tmplen, &is_utf8);
1005 k_flags = HVhek_UTF8;
1007 k_flags |= HVhek_FREEKEY;
1011 PERL_HASH_INTERNAL(hash, key, klen);
1013 PERL_HASH(hash, key, klen);
1016 /* oentry = &(HvARRAY(hv))[hash & (I32) HvMAX(hv)]; */
1017 oentry = &((HE**)xhv->xhv_array)[hash & (I32) xhv->xhv_max];
1020 for (; entry; i=0, oentry = &HeNEXT(entry), entry = *oentry) {
1021 if (HeHASH(entry) != hash) /* strings can't be equal */
1023 if (HeKLEN(entry) != (I32)klen)
1025 if (HeKEY(entry) != key && memNE(HeKEY(entry),key,klen)) /* is this it? */
1027 if ((HeKFLAGS(entry) ^ k_flags) & HVhek_UTF8)
1029 if (k_flags & HVhek_FREEKEY)
1031 /* if placeholder is here, it's already been deleted.... */
1032 if (HeVAL(entry) == &PL_sv_placeholder)
1035 return Nullsv; /* if still SvREADONLY, leave it deleted. */
1037 /* okay, really delete the placeholder... */
1038 *oentry = HeNEXT(entry);
1040 xhv->xhv_fill--; /* HvFILL(hv)-- */
1041 if (entry == xhv->xhv_eiter /* HvEITER(hv) */)
1044 hv_free_ent(hv, entry);
1045 xhv->xhv_keys--; /* HvKEYS(hv)-- */
1046 if (xhv->xhv_keys == 0)
1047 HvHASKFLAGS_off(hv);
1048 xhv->xhv_placeholders--;
1052 else if (SvREADONLY(hv) && HeVAL(entry) && SvREADONLY(HeVAL(entry))) {
1053 S_hv_notallowed(aTHX_ k_flags, key, klen,
1054 "delete readonly key '%"SVf"' from"
1058 if (flags & G_DISCARD)
1061 sv = sv_2mortal(HeVAL(entry));
1062 HeVAL(entry) = &PL_sv_placeholder;
1066 * If a restricted hash, rather than really deleting the entry, put
1067 * a placeholder there. This marks the key as being "approved", so
1068 * we can still access via not-really-existing key without raising
1071 if (SvREADONLY(hv)) {
1072 HeVAL(entry) = &PL_sv_placeholder;
1073 /* We'll be saving this slot, so the number of allocated keys
1074 * doesn't go down, but the number placeholders goes up */
1075 xhv->xhv_placeholders++; /* HvPLACEHOLDERS(hv)++ */
1077 *oentry = HeNEXT(entry);
1079 xhv->xhv_fill--; /* HvFILL(hv)-- */
1080 if (entry == xhv->xhv_eiter /* HvEITER(hv) */)
1083 hv_free_ent(hv, entry);
1084 xhv->xhv_keys--; /* HvKEYS(hv)-- */
1085 if (xhv->xhv_keys == 0)
1086 HvHASKFLAGS_off(hv);
1090 if (SvREADONLY(hv)) {
1091 S_hv_notallowed(aTHX_ k_flags, key, klen,
1092 "access disallowed key '%"SVf"' from"
1096 if (k_flags & HVhek_FREEKEY)
1102 =for apidoc hv_delete_ent
1104 Deletes a key/value pair in the hash. The value SV is removed from the
1105 hash and returned to the caller. The C<flags> value will normally be zero;
1106 if set to G_DISCARD then NULL will be returned. C<hash> can be a valid
1107 precomputed hash value, or 0 to ask for it to be computed.
1113 Perl_hv_delete_ent(pTHX_ HV *hv, SV *keysv, I32 flags, U32 hash)
1115 register XPVHV* xhv;
1120 register HE **oentry;
1128 if (SvRMAGICAL(hv)) {
1131 hv_magic_check (hv, &needs_copy, &needs_store);
1133 if (needs_copy && (entry = hv_fetch_ent(hv, keysv, TRUE, hash))) {
1135 if (SvMAGICAL(sv)) {
1139 if (mg_find(sv, PERL_MAGIC_tiedelem)) {
1140 /* No longer an element */
1141 sv_unmagic(sv, PERL_MAGIC_tiedelem);
1144 return Nullsv; /* element cannot be deleted */
1146 #ifdef ENV_IS_CASELESS
1147 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
1148 key = SvPV(keysv, klen);
1149 keysv = sv_2mortal(newSVpvn(key,klen));
1150 (void)strupr(SvPVX(keysv));
1156 xhv = (XPVHV*)SvANY(hv);
1157 if (!xhv->xhv_array /* !HvARRAY(hv) */)
1160 keysave = key = SvPV(keysv, klen);
1161 is_utf8 = (SvUTF8(keysv) != 0);
1164 key = (char*)bytes_from_utf8((U8*)key, &klen, &is_utf8);
1166 k_flags = HVhek_UTF8;
1168 k_flags |= HVhek_FREEKEY;
1172 PERL_HASH_INTERNAL(hash, key, klen);
1174 PERL_HASH(hash, key, klen);
1177 /* oentry = &(HvARRAY(hv))[hash & (I32) HvMAX(hv)]; */
1178 oentry = &((HE**)xhv->xhv_array)[hash & (I32) xhv->xhv_max];
1181 for (; entry; i=0, oentry = &HeNEXT(entry), entry = *oentry) {
1182 if (HeHASH(entry) != hash) /* strings can't be equal */
1184 if (HeKLEN(entry) != (I32)klen)
1186 if (HeKEY(entry) != key && memNE(HeKEY(entry),key,klen)) /* is this it? */
1188 if ((HeKFLAGS(entry) ^ k_flags) & HVhek_UTF8)
1190 if (k_flags & HVhek_FREEKEY)
1193 /* if placeholder is here, it's already been deleted.... */
1194 if (HeVAL(entry) == &PL_sv_placeholder)
1197 return Nullsv; /* if still SvREADONLY, leave it deleted. */
1199 /* okay, really delete the placeholder. */
1200 *oentry = HeNEXT(entry);
1202 xhv->xhv_fill--; /* HvFILL(hv)-- */
1203 if (entry == xhv->xhv_eiter /* HvEITER(hv) */)
1206 hv_free_ent(hv, entry);
1207 xhv->xhv_keys--; /* HvKEYS(hv)-- */
1208 if (xhv->xhv_keys == 0)
1209 HvHASKFLAGS_off(hv);
1210 xhv->xhv_placeholders--;
1213 else if (SvREADONLY(hv) && HeVAL(entry) && SvREADONLY(HeVAL(entry))) {
1214 S_hv_notallowed(aTHX_ k_flags, key, klen,
1215 "delete readonly key '%"SVf"' from"
1219 if (flags & G_DISCARD)
1222 sv = sv_2mortal(HeVAL(entry));
1223 HeVAL(entry) = &PL_sv_placeholder;
1227 * If a restricted hash, rather than really deleting the entry, put
1228 * a placeholder there. This marks the key as being "approved", so
1229 * we can still access via not-really-existing key without raising
1232 if (SvREADONLY(hv)) {
1233 HeVAL(entry) = &PL_sv_placeholder;
1234 /* We'll be saving this slot, so the number of allocated keys
1235 * doesn't go down, but the number placeholders goes up */
1236 xhv->xhv_placeholders++; /* HvPLACEHOLDERS(hv)++ */
1238 *oentry = HeNEXT(entry);
1240 xhv->xhv_fill--; /* HvFILL(hv)-- */
1241 if (entry == xhv->xhv_eiter /* HvEITER(hv) */)
1244 hv_free_ent(hv, entry);
1245 xhv->xhv_keys--; /* HvKEYS(hv)-- */
1246 if (xhv->xhv_keys == 0)
1247 HvHASKFLAGS_off(hv);
1251 if (SvREADONLY(hv)) {
1252 S_hv_notallowed(aTHX_ k_flags, key, klen,
1253 "delete disallowed key '%"SVf"' from"
1257 if (k_flags & HVhek_FREEKEY)
1263 =for apidoc hv_exists
1265 Returns a boolean indicating whether the specified hash key exists. The
1266 C<klen> is the length of the key.
1272 Perl_hv_exists(pTHX_ HV *hv, const char *key, I32 klen)
1274 return hv_exists_common(hv, NULL, key, klen, 0);
1278 =for apidoc hv_exists_ent
1280 Returns a boolean indicating whether the specified hash key exists. C<hash>
1281 can be a valid precomputed hash value, or 0 to ask for it to be
1288 Perl_hv_exists_ent(pTHX_ HV *hv, SV *keysv, U32 hash)
1290 return hv_exists_common(hv, keysv, NULL, 0, hash);
1294 S_hv_exists_common(pTHX_ HV *hv, SV *keysv, const char *key, I32 klen_i32,
1297 register XPVHV* xhv;
1302 const char *keysave;
1309 key = SvPV(keysv, klen);
1310 is_utf8 = (SvUTF8(keysv) != 0);
1322 if (SvRMAGICAL(hv)) {
1323 if (mg_find((SV*)hv, PERL_MAGIC_tied) || SvGMAGICAL((SV*)hv)) {
1326 if (keysv || is_utf8) {
1328 keysv = newSVpvn(key, klen);
1331 keysv = newSVsv(keysv);
1333 key = (char *)sv_2mortal(keysv);
1337 /* I don't understand why hv_exists_ent has svret and sv,
1338 whereas hv_exists only had one. */
1339 svret = sv_newmortal();
1340 sv = sv_newmortal();
1341 mg_copy((SV*)hv, sv, key, klen);
1342 magic_existspack(svret, mg_find(sv, PERL_MAGIC_tiedelem));
1343 return (bool)SvTRUE(svret);
1345 #ifdef ENV_IS_CASELESS
1346 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
1347 /* XXX This code isn't UTF8 clean. */
1348 keysv = sv_2mortal(newSVpvn(key,klen));
1349 keysave = key = strupr(SvPVX(keysv));
1356 xhv = (XPVHV*)SvANY(hv);
1357 #ifndef DYNAMIC_ENV_FETCH
1358 if (!xhv->xhv_array /* !HvARRAY(hv) */)
1363 key = (char*)bytes_from_utf8((U8*)key, &klen, &is_utf8);
1365 k_flags = HVhek_UTF8;
1367 k_flags |= HVhek_FREEKEY;
1370 PERL_HASH_INTERNAL(hash, key, klen);
1372 PERL_HASH(hash, key, klen);
1374 #ifdef DYNAMIC_ENV_FETCH
1375 if (!xhv->xhv_array /* !HvARRAY(hv) */) entry = Null(HE*);
1378 /* entry = (HvARRAY(hv))[hash & (I32) HvMAX(hv)]; */
1379 entry = ((HE**)xhv->xhv_array)[hash & (I32) xhv->xhv_max];
1380 for (; entry; entry = HeNEXT(entry)) {
1381 if (HeHASH(entry) != hash) /* strings can't be equal */
1383 if (HeKLEN(entry) != (I32)klen)
1385 if (HeKEY(entry) != key && memNE(HeKEY(entry),key,klen)) /* is this it? */
1387 if ((HeKFLAGS(entry) ^ k_flags) & HVhek_UTF8)
1389 if (k_flags & HVhek_FREEKEY)
1391 /* If we find the key, but the value is a placeholder, return false. */
1392 if (HeVAL(entry) == &PL_sv_placeholder)
1396 #ifdef DYNAMIC_ENV_FETCH /* is it out there? */
1397 if (SvRMAGICAL((SV*)hv) && mg_find((SV*)hv, PERL_MAGIC_env)) {
1399 char *env = PerlEnv_ENVgetenv_len(key,&len);
1401 sv = newSVpvn(env,len);
1403 (void)hv_store_ent(hv,keysv,sv,hash);
1404 if (k_flags & HVhek_FREEKEY)
1410 if (k_flags & HVhek_FREEKEY)
1417 S_hsplit(pTHX_ HV *hv)
1419 register XPVHV* xhv = (XPVHV*)SvANY(hv);
1420 I32 oldsize = (I32) xhv->xhv_max+1; /* HvMAX(hv)+1 (sick) */
1421 register I32 newsize = oldsize * 2;
1423 register char *a = xhv->xhv_array; /* HvARRAY(hv) */
1427 register HE **oentry;
1428 int longest_chain = 0;
1432 #if defined(STRANGE_MALLOC) || defined(MYMALLOC)
1433 Renew(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize), char);
1439 New(2, a, PERL_HV_ARRAY_ALLOC_BYTES(newsize), char);
1444 Copy(xhv->xhv_array /* HvARRAY(hv) */, a, oldsize * sizeof(HE*), char);
1445 if (oldsize >= 64) {
1446 offer_nice_chunk(xhv->xhv_array /* HvARRAY(hv) */,
1447 PERL_HV_ARRAY_ALLOC_BYTES(oldsize));
1450 Safefree(xhv->xhv_array /* HvARRAY(hv) */);
1454 Zero(&a[oldsize * sizeof(HE*)], (newsize-oldsize) * sizeof(HE*), char); /* zero 2nd half*/
1455 xhv->xhv_max = --newsize; /* HvMAX(hv) = --newsize */
1456 xhv->xhv_array = a; /* HvARRAY(hv) = a */
1459 for (i=0; i<oldsize; i++,aep++) {
1460 int left_length = 0;
1461 int right_length = 0;
1463 if (!*aep) /* non-existent */
1466 for (oentry = aep, entry = *aep; entry; entry = *oentry) {
1467 if ((HeHASH(entry) & newsize) != (U32)i) {
1468 *oentry = HeNEXT(entry);
1469 HeNEXT(entry) = *bep;
1471 xhv->xhv_fill++; /* HvFILL(hv)++ */
1477 oentry = &HeNEXT(entry);
1481 if (!*aep) /* everything moved */
1482 xhv->xhv_fill--; /* HvFILL(hv)-- */
1483 /* I think we don't actually need to keep track of the longest length,
1484 merely flag if anything is too long. But for the moment while
1485 developing this code I'll track it. */
1486 if (left_length > longest_chain)
1487 longest_chain = left_length;
1488 if (right_length > longest_chain)
1489 longest_chain = right_length;
1493 /* Pick your policy for "hashing isn't working" here: */
1494 if (longest_chain <= HV_MAX_LENGTH_BEFORE_SPLIT /* split worked? */
1499 if (hv == PL_strtab) {
1500 /* Urg. Someone is doing something nasty to the string table.
1505 /* Awooga. Awooga. Pathological data. */
1506 /*PerlIO_printf(PerlIO_stderr(), "%p %d of %d with %d/%d buckets\n", hv,
1507 longest_chain, HvTOTALKEYS(hv), HvFILL(hv), 1+HvMAX(hv));*/
1510 Newz(2, a, PERL_HV_ARRAY_ALLOC_BYTES(newsize), char);
1511 was_shared = HvSHAREKEYS(hv);
1514 HvSHAREKEYS_off(hv);
1517 aep = (HE **) xhv->xhv_array;
1519 for (i=0; i<newsize; i++,aep++) {
1522 /* We're going to trash this HE's next pointer when we chain it
1523 into the new hash below, so store where we go next. */
1524 HE *next = HeNEXT(entry);
1528 PERL_HASH_INTERNAL(hash, HeKEY(entry), HeKLEN(entry));
1533 = save_hek_flags(HeKEY(entry), HeKLEN(entry),
1534 hash, HeKFLAGS(entry));
1535 unshare_hek (HeKEY_hek(entry));
1536 HeKEY_hek(entry) = new_hek;
1538 /* Not shared, so simply write the new hash in. */
1539 HeHASH(entry) = hash;
1541 /*PerlIO_printf(PerlIO_stderr(), "%d ", HeKFLAGS(entry));*/
1542 HEK_REHASH_on(HeKEY_hek(entry));
1543 /*PerlIO_printf(PerlIO_stderr(), "%d\n", HeKFLAGS(entry));*/
1545 /* Copy oentry to the correct new chain. */
1546 bep = ((HE**)a) + (hash & (I32) xhv->xhv_max);
1548 xhv->xhv_fill++; /* HvFILL(hv)++ */
1549 HeNEXT(entry) = *bep;
1555 Safefree (xhv->xhv_array);
1556 xhv->xhv_array = a; /* HvARRAY(hv) = a */
1560 Perl_hv_ksplit(pTHX_ HV *hv, IV newmax)
1562 register XPVHV* xhv = (XPVHV*)SvANY(hv);
1563 I32 oldsize = (I32) xhv->xhv_max+1; /* HvMAX(hv)+1 (sick) */
1564 register I32 newsize;
1570 register HE **oentry;
1572 newsize = (I32) newmax; /* possible truncation here */
1573 if (newsize != newmax || newmax <= oldsize)
1575 while ((newsize & (1 + ~newsize)) != newsize) {
1576 newsize &= ~(newsize & (1 + ~newsize)); /* get proper power of 2 */
1578 if (newsize < newmax)
1580 if (newsize < newmax)
1581 return; /* overflow detection */
1583 a = xhv->xhv_array; /* HvARRAY(hv) */
1586 #if defined(STRANGE_MALLOC) || defined(MYMALLOC)
1587 Renew(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize), char);
1593 New(2, a, PERL_HV_ARRAY_ALLOC_BYTES(newsize), char);
1598 Copy(xhv->xhv_array /* HvARRAY(hv) */, a, oldsize * sizeof(HE*), char);
1599 if (oldsize >= 64) {
1600 offer_nice_chunk(xhv->xhv_array /* HvARRAY(hv) */,
1601 PERL_HV_ARRAY_ALLOC_BYTES(oldsize));
1604 Safefree(xhv->xhv_array /* HvARRAY(hv) */);
1607 Zero(&a[oldsize * sizeof(HE*)], (newsize-oldsize) * sizeof(HE*), char); /* zero 2nd half*/
1610 Newz(0, a, PERL_HV_ARRAY_ALLOC_BYTES(newsize), char);
1612 xhv->xhv_max = --newsize; /* HvMAX(hv) = --newsize */
1613 xhv->xhv_array = a; /* HvARRAY(hv) = a */
1614 if (!xhv->xhv_fill /* !HvFILL(hv) */) /* skip rest if no entries */
1618 for (i=0; i<oldsize; i++,aep++) {
1619 if (!*aep) /* non-existent */
1621 for (oentry = aep, entry = *aep; entry; entry = *oentry) {
1622 if ((j = (HeHASH(entry) & newsize)) != i) {
1624 *oentry = HeNEXT(entry);
1625 if (!(HeNEXT(entry) = aep[j]))
1626 xhv->xhv_fill++; /* HvFILL(hv)++ */
1631 oentry = &HeNEXT(entry);
1633 if (!*aep) /* everything moved */
1634 xhv->xhv_fill--; /* HvFILL(hv)-- */
1641 Creates a new HV. The reference count is set to 1.
1650 register XPVHV* xhv;
1652 hv = (HV*)NEWSV(502,0);
1653 sv_upgrade((SV *)hv, SVt_PVHV);
1654 xhv = (XPVHV*)SvANY(hv);
1657 #ifndef NODEFAULT_SHAREKEYS
1658 HvSHAREKEYS_on(hv); /* key-sharing on by default */
1661 xhv->xhv_max = 7; /* HvMAX(hv) = 7 (start with 8 buckets) */
1662 xhv->xhv_fill = 0; /* HvFILL(hv) = 0 */
1663 xhv->xhv_pmroot = 0; /* HvPMROOT(hv) = 0 */
1664 (void)hv_iterinit(hv); /* so each() will start off right */
1669 Perl_newHVhv(pTHX_ HV *ohv)
1672 STRLEN hv_max, hv_fill;
1674 if (!ohv || (hv_fill = HvFILL(ohv)) == 0)
1676 hv_max = HvMAX(ohv);
1678 if (!SvMAGICAL((SV *)ohv)) {
1679 /* It's an ordinary hash, so copy it fast. AMS 20010804 */
1681 bool shared = !!HvSHAREKEYS(ohv);
1682 HE **ents, **oents = (HE **)HvARRAY(ohv);
1684 New(0, a, PERL_HV_ARRAY_ALLOC_BYTES(hv_max+1), char);
1687 /* In each bucket... */
1688 for (i = 0; i <= hv_max; i++) {
1689 HE *prev = NULL, *ent = NULL, *oent = oents[i];
1696 /* Copy the linked list of entries. */
1697 for (oent = oents[i]; oent; oent = HeNEXT(oent)) {
1698 U32 hash = HeHASH(oent);
1699 char *key = HeKEY(oent);
1700 STRLEN len = HeKLEN(oent);
1701 int flags = HeKFLAGS(oent);
1704 HeVAL(ent) = newSVsv(HeVAL(oent));
1706 = shared ? share_hek_flags(key, len, hash, flags)
1707 : save_hek_flags(key, len, hash, flags);
1718 HvFILL(hv) = hv_fill;
1719 HvTOTALKEYS(hv) = HvTOTALKEYS(ohv);
1723 /* Iterate over ohv, copying keys and values one at a time. */
1725 I32 riter = HvRITER(ohv);
1726 HE *eiter = HvEITER(ohv);
1728 /* Can we use fewer buckets? (hv_max is always 2^n-1) */
1729 while (hv_max && hv_max + 1 >= hv_fill * 2)
1730 hv_max = hv_max / 2;
1734 while ((entry = hv_iternext_flags(ohv, 0))) {
1735 hv_store_flags(hv, HeKEY(entry), HeKLEN(entry),
1736 newSVsv(HeVAL(entry)), HeHASH(entry),
1739 HvRITER(ohv) = riter;
1740 HvEITER(ohv) = eiter;
1747 Perl_hv_free_ent(pTHX_ HV *hv, register HE *entry)
1754 if (val && isGV(val) && GvCVu(val) && HvNAME(hv))
1755 PL_sub_generation++; /* may be deletion of method from stash */
1757 if (HeKLEN(entry) == HEf_SVKEY) {
1758 SvREFCNT_dec(HeKEY_sv(entry));
1759 Safefree(HeKEY_hek(entry));
1761 else if (HvSHAREKEYS(hv))
1762 unshare_hek(HeKEY_hek(entry));
1764 Safefree(HeKEY_hek(entry));
1769 Perl_hv_delayfree_ent(pTHX_ HV *hv, register HE *entry)
1773 if (isGV(HeVAL(entry)) && GvCVu(HeVAL(entry)) && HvNAME(hv))
1774 PL_sub_generation++; /* may be deletion of method from stash */
1775 sv_2mortal(HeVAL(entry)); /* free between statements */
1776 if (HeKLEN(entry) == HEf_SVKEY) {
1777 sv_2mortal(HeKEY_sv(entry));
1778 Safefree(HeKEY_hek(entry));
1780 else if (HvSHAREKEYS(hv))
1781 unshare_hek(HeKEY_hek(entry));
1783 Safefree(HeKEY_hek(entry));
1788 =for apidoc hv_clear
1790 Clears a hash, making it empty.
1796 Perl_hv_clear(pTHX_ HV *hv)
1798 register XPVHV* xhv;
1802 DEBUG_A(Perl_hv_assert(aTHX_ hv));
1804 xhv = (XPVHV*)SvANY(hv);
1806 if (SvREADONLY(hv) && xhv->xhv_array != NULL) {
1807 /* restricted hash: convert all keys to placeholders */
1810 for (i = 0; i <= (I32) xhv->xhv_max; i++) {
1811 entry = ((HE**)xhv->xhv_array)[i];
1812 for (; entry; entry = HeNEXT(entry)) {
1813 /* not already placeholder */
1814 if (HeVAL(entry) != &PL_sv_placeholder) {
1815 if (HeVAL(entry) && SvREADONLY(HeVAL(entry))) {
1816 SV* keysv = hv_iterkeysv(entry);
1818 "Attempt to delete readonly key '%"SVf"' from a restricted hash",
1821 SvREFCNT_dec(HeVAL(entry));
1822 HeVAL(entry) = &PL_sv_placeholder;
1823 xhv->xhv_placeholders++; /* HvPLACEHOLDERS(hv)++ */
1831 xhv->xhv_placeholders = 0; /* HvPLACEHOLDERS(hv) = 0 */
1832 if (xhv->xhv_array /* HvARRAY(hv) */)
1833 (void)memzero(xhv->xhv_array /* HvARRAY(hv) */,
1834 (xhv->xhv_max+1 /* HvMAX(hv)+1 */) * sizeof(HE*));
1839 HvHASKFLAGS_off(hv);
1844 S_hfreeentries(pTHX_ HV *hv)
1846 register HE **array;
1848 register HE *oentry = Null(HE*);
1859 array = HvARRAY(hv);
1860 /* make everyone else think the array is empty, so that the destructors
1861 * called for freed entries can't recusively mess with us */
1862 HvARRAY(hv) = Null(HE**);
1864 ((XPVHV*) SvANY(hv))->xhv_keys = 0;
1870 entry = HeNEXT(entry);
1871 hv_free_ent(hv, oentry);
1876 entry = array[riter];
1879 HvARRAY(hv) = array;
1880 (void)hv_iterinit(hv);
1884 =for apidoc hv_undef
1892 Perl_hv_undef(pTHX_ HV *hv)
1894 register XPVHV* xhv;
1897 DEBUG_A(Perl_hv_assert(aTHX_ hv));
1898 xhv = (XPVHV*)SvANY(hv);
1900 Safefree(xhv->xhv_array /* HvARRAY(hv) */);
1903 hv_delete(PL_stashcache, HvNAME(hv), strlen(HvNAME(hv)), G_DISCARD);
1904 Safefree(HvNAME(hv));
1907 xhv->xhv_max = 7; /* HvMAX(hv) = 7 (it's a normal hash) */
1908 xhv->xhv_array = 0; /* HvARRAY(hv) = 0 */
1909 xhv->xhv_placeholders = 0; /* HvPLACEHOLDERS(hv) = 0 */
1916 =for apidoc hv_iterinit
1918 Prepares a starting point to traverse a hash table. Returns the number of
1919 keys in the hash (i.e. the same as C<HvKEYS(tb)>). The return value is
1920 currently only meaningful for hashes without tie magic.
1922 NOTE: Before version 5.004_65, C<hv_iterinit> used to return the number of
1923 hash buckets that happen to be in use. If you still need that esoteric
1924 value, you can get it through the macro C<HvFILL(tb)>.
1931 Perl_hv_iterinit(pTHX_ HV *hv)
1933 register XPVHV* xhv;
1937 Perl_croak(aTHX_ "Bad hash");
1938 xhv = (XPVHV*)SvANY(hv);
1939 entry = xhv->xhv_eiter; /* HvEITER(hv) */
1940 if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */
1942 hv_free_ent(hv, entry);
1944 xhv->xhv_riter = -1; /* HvRITER(hv) = -1 */
1945 xhv->xhv_eiter = Null(HE*); /* HvEITER(hv) = Null(HE*) */
1946 /* used to be xhv->xhv_fill before 5.004_65 */
1947 return XHvTOTALKEYS(xhv);
1950 =for apidoc hv_iternext
1952 Returns entries from a hash iterator. See C<hv_iterinit>.
1954 You may call C<hv_delete> or C<hv_delete_ent> on the hash entry that the
1955 iterator currently points to, without losing your place or invalidating your
1956 iterator. Note that in this case the current entry is deleted from the hash
1957 with your iterator holding the last reference to it. Your iterator is flagged
1958 to free the entry on the next call to C<hv_iternext>, so you must not discard
1959 your iterator immediately else the entry will leak - call C<hv_iternext> to
1960 trigger the resource deallocation.
1966 Perl_hv_iternext(pTHX_ HV *hv)
1968 return hv_iternext_flags(hv, 0);
1972 =for apidoc hv_iternext_flags
1974 Returns entries from a hash iterator. See C<hv_iterinit> and C<hv_iternext>.
1975 The C<flags> value will normally be zero; if HV_ITERNEXT_WANTPLACEHOLDERS is
1976 set the placeholders keys (for restricted hashes) will be returned in addition
1977 to normal keys. By default placeholders are automatically skipped over.
1978 Currently a placeholder is implemented with a value that is
1979 C<&Perl_sv_placeholder>. Note that the implementation of placeholders and
1980 restricted hashes may change, and the implementation currently is
1981 insufficiently abstracted for any change to be tidy.
1987 Perl_hv_iternext_flags(pTHX_ HV *hv, I32 flags)
1989 register XPVHV* xhv;
1995 Perl_croak(aTHX_ "Bad hash");
1996 xhv = (XPVHV*)SvANY(hv);
1997 oldentry = entry = xhv->xhv_eiter; /* HvEITER(hv) */
1999 if ((mg = SvTIED_mg((SV*)hv, PERL_MAGIC_tied))) {
2000 SV *key = sv_newmortal();
2002 sv_setsv(key, HeSVKEY_force(entry));
2003 SvREFCNT_dec(HeSVKEY(entry)); /* get rid of previous key */
2009 /* one HE per MAGICAL hash */
2010 xhv->xhv_eiter = entry = new_HE(); /* HvEITER(hv) = new_HE() */
2012 Newz(54, k, HEK_BASESIZE + sizeof(SV*), char);
2014 HeKEY_hek(entry) = hek;
2015 HeKLEN(entry) = HEf_SVKEY;
2017 magic_nextpack((SV*) hv,mg,key);
2019 /* force key to stay around until next time */
2020 HeSVKEY_set(entry, SvREFCNT_inc(key));
2021 return entry; /* beware, hent_val is not set */
2024 SvREFCNT_dec(HeVAL(entry));
2025 Safefree(HeKEY_hek(entry));
2027 xhv->xhv_eiter = Null(HE*); /* HvEITER(hv) = Null(HE*) */
2030 #ifdef DYNAMIC_ENV_FETCH /* set up %ENV for iteration */
2031 if (!entry && SvRMAGICAL((SV*)hv) && mg_find((SV*)hv, PERL_MAGIC_env))
2035 if (!xhv->xhv_array /* !HvARRAY(hv) */)
2036 Newz(506, xhv->xhv_array /* HvARRAY(hv) */,
2037 PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */),
2039 /* At start of hash, entry is NULL. */
2042 entry = HeNEXT(entry);
2043 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
2045 * Skip past any placeholders -- don't want to include them in
2048 while (entry && HeVAL(entry) == &PL_sv_placeholder) {
2049 entry = HeNEXT(entry);
2054 /* OK. Come to the end of the current list. Grab the next one. */
2056 xhv->xhv_riter++; /* HvRITER(hv)++ */
2057 if (xhv->xhv_riter > (I32)xhv->xhv_max /* HvRITER(hv) > HvMAX(hv) */) {
2058 /* There is no next one. End of the hash. */
2059 xhv->xhv_riter = -1; /* HvRITER(hv) = -1 */
2062 /* entry = (HvARRAY(hv))[HvRITER(hv)]; */
2063 entry = ((HE**)xhv->xhv_array)[xhv->xhv_riter];
2065 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
2066 /* If we have an entry, but it's a placeholder, don't count it.
2068 while (entry && HeVAL(entry) == &PL_sv_placeholder)
2069 entry = HeNEXT(entry);
2071 /* Will loop again if this linked list starts NULL
2072 (for HV_ITERNEXT_WANTPLACEHOLDERS)
2073 or if we run through it and find only placeholders. */
2076 if (oldentry && HvLAZYDEL(hv)) { /* was deleted earlier? */
2078 hv_free_ent(hv, oldentry);
2081 /*if (HvREHASH(hv) && entry && !HeKREHASH(entry))
2082 PerlIO_printf(PerlIO_stderr(), "Awooga %p %p\n", hv, entry);*/
2084 xhv->xhv_eiter = entry; /* HvEITER(hv) = entry */
2089 =for apidoc hv_iterkey
2091 Returns the key from the current position of the hash iterator. See
2098 Perl_hv_iterkey(pTHX_ register HE *entry, I32 *retlen)
2100 if (HeKLEN(entry) == HEf_SVKEY) {
2102 char *p = SvPV(HeKEY_sv(entry), len);
2107 *retlen = HeKLEN(entry);
2108 return HeKEY(entry);
2112 /* unlike hv_iterval(), this always returns a mortal copy of the key */
2114 =for apidoc hv_iterkeysv
2116 Returns the key as an C<SV*> from the current position of the hash
2117 iterator. The return value will always be a mortal copy of the key. Also
2124 Perl_hv_iterkeysv(pTHX_ register HE *entry)
2126 if (HeKLEN(entry) != HEf_SVKEY) {
2127 HEK *hek = HeKEY_hek(entry);
2128 int flags = HEK_FLAGS(hek);
2131 if (flags & HVhek_WASUTF8) {
2133 Andreas would like keys he put in as utf8 to come back as utf8
2135 STRLEN utf8_len = HEK_LEN(hek);
2136 U8 *as_utf8 = bytes_to_utf8 ((U8*)HEK_KEY(hek), &utf8_len);
2138 sv = newSVpvn ((char*)as_utf8, utf8_len);
2140 Safefree (as_utf8); /* bytes_to_utf8() allocates a new string */
2141 } else if (flags & HVhek_REHASH) {
2142 /* We don't have a pointer to the hv, so we have to replicate the
2143 flag into every HEK. This hv is using custom a hasing
2144 algorithm. Hence we can't return a shared string scalar, as
2145 that would contain the (wrong) hash value, and might get passed
2146 into an hv routine with a regular hash */
2148 sv = newSVpvn (HEK_KEY(hek), HEK_LEN(hek));
2152 sv = newSVpvn_share(HEK_KEY(hek),
2153 (HEK_UTF8(hek) ? -HEK_LEN(hek) : HEK_LEN(hek)),
2156 return sv_2mortal(sv);
2158 return sv_mortalcopy(HeKEY_sv(entry));
2162 =for apidoc hv_iterval
2164 Returns the value from the current position of the hash iterator. See
2171 Perl_hv_iterval(pTHX_ HV *hv, register HE *entry)
2173 if (SvRMAGICAL(hv)) {
2174 if (mg_find((SV*)hv, PERL_MAGIC_tied)) {
2175 SV* sv = sv_newmortal();
2176 if (HeKLEN(entry) == HEf_SVKEY)
2177 mg_copy((SV*)hv, sv, (char*)HeKEY_sv(entry), HEf_SVKEY);
2178 else mg_copy((SV*)hv, sv, HeKEY(entry), HeKLEN(entry));
2182 return HeVAL(entry);
2186 =for apidoc hv_iternextsv
2188 Performs an C<hv_iternext>, C<hv_iterkey>, and C<hv_iterval> in one
2195 Perl_hv_iternextsv(pTHX_ HV *hv, char **key, I32 *retlen)
2198 if ( (he = hv_iternext_flags(hv, 0)) == NULL)
2200 *key = hv_iterkey(he, retlen);
2201 return hv_iterval(hv, he);
2205 =for apidoc hv_magic
2207 Adds magic to a hash. See C<sv_magic>.
2213 Perl_hv_magic(pTHX_ HV *hv, GV *gv, int how)
2215 sv_magic((SV*)hv, (SV*)gv, how, Nullch, 0);
2218 #if 0 /* use the macro from hv.h instead */
2221 Perl_sharepvn(pTHX_ const char *sv, I32 len, U32 hash)
2223 return HEK_KEY(share_hek(sv, len, hash));
2228 /* possibly free a shared string if no one has access to it
2229 * len and hash must both be valid for str.
2232 Perl_unsharepvn(pTHX_ const char *str, I32 len, U32 hash)
2234 unshare_hek_or_pvn (NULL, str, len, hash);
2239 Perl_unshare_hek(pTHX_ HEK *hek)
2241 unshare_hek_or_pvn(hek, NULL, 0, 0);
2244 /* possibly free a shared string if no one has access to it
2245 hek if non-NULL takes priority over the other 3, else str, len and hash
2246 are used. If so, len and hash must both be valid for str.
2249 S_unshare_hek_or_pvn(pTHX_ HEK *hek, const char *str, I32 len, U32 hash)
2251 register XPVHV* xhv;
2253 register HE **oentry;
2256 bool is_utf8 = FALSE;
2258 const char *save = str;
2261 hash = HEK_HASH(hek);
2262 } else if (len < 0) {
2263 STRLEN tmplen = -len;
2265 /* See the note in hv_fetch(). --jhi */
2266 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
2269 k_flags = HVhek_UTF8;
2271 k_flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
2274 /* what follows is the moral equivalent of:
2275 if ((Svp = hv_fetch(PL_strtab, tmpsv, FALSE, hash))) {
2276 if (--*Svp == Nullsv)
2277 hv_delete(PL_strtab, str, len, G_DISCARD, hash);
2279 xhv = (XPVHV*)SvANY(PL_strtab);
2280 /* assert(xhv_array != 0) */
2282 /* oentry = &(HvARRAY(hv))[hash & (I32) HvMAX(hv)]; */
2283 oentry = &((HE**)xhv->xhv_array)[hash & (I32) xhv->xhv_max];
2285 for (entry = *oentry; entry; i=0, oentry = &HeNEXT(entry), entry = *oentry) {
2286 if (HeKEY_hek(entry) != hek)
2292 int flags_masked = k_flags & HVhek_MASK;
2293 for (entry = *oentry; entry; i=0, oentry = &HeNEXT(entry), entry = *oentry) {
2294 if (HeHASH(entry) != hash) /* strings can't be equal */
2296 if (HeKLEN(entry) != len)
2298 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
2300 if (HeKFLAGS(entry) != flags_masked)
2308 if (--HeVAL(entry) == Nullsv) {
2309 *oentry = HeNEXT(entry);
2311 xhv->xhv_fill--; /* HvFILL(hv)-- */
2312 Safefree(HeKEY_hek(entry));
2314 xhv->xhv_keys--; /* HvKEYS(hv)-- */
2318 UNLOCK_STRTAB_MUTEX;
2319 if (!found && ckWARN_d(WARN_INTERNAL))
2320 Perl_warner(aTHX_ packWARN(WARN_INTERNAL),
2321 "Attempt to free non-existent shared string '%s'%s",
2322 hek ? HEK_KEY(hek) : str,
2323 (k_flags & HVhek_UTF8) ? " (utf8)" : "");
2324 if (k_flags & HVhek_FREEKEY)
2328 /* get a (constant) string ptr from the global string table
2329 * string will get added if it is not already there.
2330 * len and hash must both be valid for str.
2333 Perl_share_hek(pTHX_ const char *str, I32 len, register U32 hash)
2335 bool is_utf8 = FALSE;
2337 const char *save = str;
2340 STRLEN tmplen = -len;
2342 /* See the note in hv_fetch(). --jhi */
2343 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
2345 /* If we were able to downgrade here, then than means that we were passed
2346 in a key which only had chars 0-255, but was utf8 encoded. */
2349 /* If we found we were able to downgrade the string to bytes, then
2350 we should flag that it needs upgrading on keys or each. Also flag
2351 that we need share_hek_flags to free the string. */
2353 flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
2356 return share_hek_flags (str, len, hash, flags);
2360 S_share_hek_flags(pTHX_ const char *str, I32 len, register U32 hash, int flags)
2362 register XPVHV* xhv;
2364 register HE **oentry;
2367 int flags_masked = flags & HVhek_MASK;
2369 /* what follows is the moral equivalent of:
2371 if (!(Svp = hv_fetch(PL_strtab, str, len, FALSE)))
2372 hv_store(PL_strtab, str, len, Nullsv, hash);
2374 Can't rehash the shared string table, so not sure if it's worth
2375 counting the number of entries in the linked list
2377 xhv = (XPVHV*)SvANY(PL_strtab);
2378 /* assert(xhv_array != 0) */
2380 /* oentry = &(HvARRAY(hv))[hash & (I32) HvMAX(hv)]; */
2381 oentry = &((HE**)xhv->xhv_array)[hash & (I32) xhv->xhv_max];
2382 for (entry = *oentry; entry; i=0, entry = HeNEXT(entry)) {
2383 if (HeHASH(entry) != hash) /* strings can't be equal */
2385 if (HeKLEN(entry) != len)
2387 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
2389 if (HeKFLAGS(entry) != flags_masked)
2396 HeKEY_hek(entry) = save_hek_flags(str, len, hash, flags);
2397 HeVAL(entry) = Nullsv;
2398 HeNEXT(entry) = *oentry;
2400 xhv->xhv_keys++; /* HvKEYS(hv)++ */
2401 if (i) { /* initial entry? */
2402 xhv->xhv_fill++; /* HvFILL(hv)++ */
2403 } else if (xhv->xhv_keys > (IV)xhv->xhv_max /* HvKEYS(hv) > HvMAX(hv) */) {
2408 ++HeVAL(entry); /* use value slot as REFCNT */
2409 UNLOCK_STRTAB_MUTEX;
2411 if (flags & HVhek_FREEKEY)
2414 return HeKEY_hek(entry);
2419 =for apidoc hv_assert
2421 Check that a hash is in an internally consistent state.
2427 Perl_hv_assert(pTHX_ HV *hv)
2431 int placeholders = 0;
2434 I32 riter = HvRITER(hv);
2435 HE *eiter = HvEITER(hv);
2437 (void)hv_iterinit(hv);
2439 while ((entry = hv_iternext_flags(hv, HV_ITERNEXT_WANTPLACEHOLDERS))) {
2440 /* sanity check the values */
2441 if (HeVAL(entry) == &PL_sv_placeholder) {
2446 /* sanity check the keys */
2447 if (HeSVKEY(entry)) {
2448 /* Don't know what to check on SV keys. */
2449 } else if (HeKUTF8(entry)) {
2451 if (HeKWASUTF8(entry)) {
2452 PerlIO_printf(Perl_debug_log,
2453 "hash key has both WASUFT8 and UTF8: '%.*s'\n",
2454 (int) HeKLEN(entry), HeKEY(entry));
2457 } else if (HeKWASUTF8(entry)) {
2461 if (!SvTIED_mg((SV*)hv, PERL_MAGIC_tied)) {
2462 if (HvUSEDKEYS(hv) != real) {
2463 PerlIO_printf(Perl_debug_log, "Count %d key(s), but hash reports %d\n",
2464 (int) real, (int) HvUSEDKEYS(hv));
2467 if (HvPLACEHOLDERS(hv) != placeholders) {
2468 PerlIO_printf(Perl_debug_log,
2469 "Count %d placeholder(s), but hash reports %d\n",
2470 (int) placeholders, (int) HvPLACEHOLDERS(hv));
2474 if (withflags && ! HvHASKFLAGS(hv)) {
2475 PerlIO_printf(Perl_debug_log,
2476 "Hash has HASKFLAGS off but I count %d key(s) with flags\n",
2483 HvRITER(hv) = riter; /* Restore hash iterator state */
2484 HvEITER(hv) = eiter;