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Adding const qualifiers
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a0d0e21e 1/* hv.c
79072805 2 *
4bb101f2 3 * Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
af3babe4 4 * 2000, 2001, 2002, 2003, 2004, 2005, by Larry Wall and others
79072805
LW
5 *
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.
8 *
a0d0e21e
LW
9 */
10
11/*
12 * "I sit beside the fire and think of all that I have seen." --Bilbo
79072805
LW
13 */
14
d5afce77
RB
15/*
16=head1 Hash Manipulation Functions
166f8a29
DM
17
18A HV structure represents a Perl hash. It consists mainly of an array
19of pointers, each of which points to a linked list of HE structures. The
20array is indexed by the hash function of the key, so each linked list
21represents all the hash entries with the same hash value. Each HE contains
22a pointer to the actual value, plus a pointer to a HEK structure which
23holds the key and hash value.
24
25=cut
26
d5afce77
RB
27*/
28
79072805 29#include "EXTERN.h"
864dbfa3 30#define PERL_IN_HV_C
3d78eb94 31#define PERL_HASH_INTERNAL_ACCESS
79072805
LW
32#include "perl.h"
33
d8012aaf 34#define HV_MAX_LENGTH_BEFORE_SPLIT 14
fdcd69b6 35
76e3520e 36STATIC HE*
cea2e8a9 37S_new_he(pTHX)
4633a7c4
LW
38{
39 HE* he;
333f433b
DG
40 LOCK_SV_MUTEX;
41 if (!PL_he_root)
8aacddc1 42 more_he();
333f433b
DG
43 he = PL_he_root;
44 PL_he_root = HeNEXT(he);
45 UNLOCK_SV_MUTEX;
46 return he;
4633a7c4
LW
47}
48
76e3520e 49STATIC void
cea2e8a9 50S_del_he(pTHX_ HE *p)
4633a7c4 51{
333f433b 52 LOCK_SV_MUTEX;
3280af22
NIS
53 HeNEXT(p) = (HE*)PL_he_root;
54 PL_he_root = p;
333f433b 55 UNLOCK_SV_MUTEX;
4633a7c4
LW
56}
57
333f433b 58STATIC void
cea2e8a9 59S_more_he(pTHX)
4633a7c4
LW
60{
61 register HE* he;
62 register HE* heend;
612f20c3
GS
63 XPV *ptr;
64 New(54, ptr, 1008/sizeof(XPV), XPV);
65 ptr->xpv_pv = (char*)PL_he_arenaroot;
66 PL_he_arenaroot = ptr;
67
68 he = (HE*)ptr;
4633a7c4 69 heend = &he[1008 / sizeof(HE) - 1];
612f20c3 70 PL_he_root = ++he;
4633a7c4 71 while (he < heend) {
8aacddc1
NIS
72 HeNEXT(he) = (HE*)(he + 1);
73 he++;
4633a7c4 74 }
fde52b5c 75 HeNEXT(he) = 0;
4633a7c4
LW
76}
77
d33b2eba
GS
78#ifdef PURIFY
79
80#define new_HE() (HE*)safemalloc(sizeof(HE))
81#define del_HE(p) safefree((char*)p)
82
83#else
84
85#define new_HE() new_he()
86#define del_HE(p) del_he(p)
87
88#endif
89
76e3520e 90STATIC HEK *
19692e8d 91S_save_hek_flags(pTHX_ const char *str, I32 len, U32 hash, int flags)
bbce6d69 92{
35a4481c 93 const int flags_masked = flags & HVhek_MASK;
bbce6d69
PP
94 char *k;
95 register HEK *hek;
1c846c1f 96
e05949c7 97 New(54, k, HEK_BASESIZE + len + 2, char);
bbce6d69 98 hek = (HEK*)k;
ff68c719 99 Copy(str, HEK_KEY(hek), len, char);
e05949c7 100 HEK_KEY(hek)[len] = 0;
ff68c719
PP
101 HEK_LEN(hek) = len;
102 HEK_HASH(hek) = hash;
dcf933a4
NC
103 HEK_FLAGS(hek) = (unsigned char)flags_masked;
104
105 if (flags & HVhek_FREEKEY)
106 Safefree(str);
bbce6d69
PP
107 return hek;
108}
109
dd28f7bb
DM
110/* free the pool of temporary HE/HEK pairs retunrned by hv_fetch_ent
111 * for tied hashes */
112
113void
114Perl_free_tied_hv_pool(pTHX)
115{
116 HE *ohe;
117 HE *he = PL_hv_fetch_ent_mh;
118 while (he) {
119 Safefree(HeKEY_hek(he));
120 ohe = he;
121 he = HeNEXT(he);
122 del_HE(ohe);
123 }
bf9cdc68 124 PL_hv_fetch_ent_mh = Nullhe;
dd28f7bb
DM
125}
126
d18c6117
GS
127#if defined(USE_ITHREADS)
128HE *
a8fc9800 129Perl_he_dup(pTHX_ HE *e, bool shared, CLONE_PARAMS* param)
d18c6117
GS
130{
131 HE *ret;
132
133 if (!e)
134 return Nullhe;
7766f137
GS
135 /* look for it in the table first */
136 ret = (HE*)ptr_table_fetch(PL_ptr_table, e);
137 if (ret)
138 return ret;
139
140 /* create anew and remember what it is */
d33b2eba 141 ret = new_HE();
7766f137
GS
142 ptr_table_store(PL_ptr_table, e, ret);
143
d2d73c3e 144 HeNEXT(ret) = he_dup(HeNEXT(e),shared, param);
dd28f7bb
DM
145 if (HeKLEN(e) == HEf_SVKEY) {
146 char *k;
147 New(54, k, HEK_BASESIZE + sizeof(SV*), char);
148 HeKEY_hek(ret) = (HEK*)k;
d2d73c3e 149 HeKEY_sv(ret) = SvREFCNT_inc(sv_dup(HeKEY_sv(e), param));
dd28f7bb 150 }
d18c6117 151 else if (shared)
19692e8d
NC
152 HeKEY_hek(ret) = share_hek_flags(HeKEY(e), HeKLEN(e), HeHASH(e),
153 HeKFLAGS(e));
d18c6117 154 else
19692e8d
NC
155 HeKEY_hek(ret) = save_hek_flags(HeKEY(e), HeKLEN(e), HeHASH(e),
156 HeKFLAGS(e));
d2d73c3e 157 HeVAL(ret) = SvREFCNT_inc(sv_dup(HeVAL(e), param));
d18c6117
GS
158 return ret;
159}
160#endif /* USE_ITHREADS */
161
1b1f1335 162static void
2393f1b9
JH
163S_hv_notallowed(pTHX_ int flags, const char *key, I32 klen,
164 const char *msg)
1b1f1335 165{
2393f1b9 166 SV *sv = sv_newmortal(), *esv = sv_newmortal();
19692e8d 167 if (!(flags & HVhek_FREEKEY)) {
1b1f1335
NIS
168 sv_setpvn(sv, key, klen);
169 }
170 else {
171 /* Need to free saved eventually assign to mortal SV */
34c3c4e3 172 /* XXX is this line an error ???: SV *sv = sv_newmortal(); */
1b1f1335
NIS
173 sv_usepvn(sv, (char *) key, klen);
174 }
19692e8d 175 if (flags & HVhek_UTF8) {
1b1f1335
NIS
176 SvUTF8_on(sv);
177 }
2393f1b9
JH
178 Perl_sv_setpvf(aTHX_ esv, "Attempt to %s a restricted hash", msg);
179 Perl_croak(aTHX_ SvPVX(esv), sv);
1b1f1335
NIS
180}
181
fde52b5c
PP
182/* (klen == HEf_SVKEY) is special for MAGICAL hv entries, meaning key slot
183 * contains an SV* */
184
34a6f7b4
NC
185#define HV_FETCH_ISSTORE 0x01
186#define HV_FETCH_ISEXISTS 0x02
187#define HV_FETCH_LVALUE 0x04
188#define HV_FETCH_JUST_SV 0x08
189
190/*
191=for apidoc hv_store
192
193Stores an SV in a hash. The hash key is specified as C<key> and C<klen> is
194the length of the key. The C<hash> parameter is the precomputed hash
195value; if it is zero then Perl will compute it. The return value will be
196NULL if the operation failed or if the value did not need to be actually
197stored within the hash (as in the case of tied hashes). Otherwise it can
198be dereferenced to get the original C<SV*>. Note that the caller is
199responsible for suitably incrementing the reference count of C<val> before
200the call, and decrementing it if the function returned NULL. Effectively
201a successful hv_store takes ownership of one reference to C<val>. This is
202usually what you want; a newly created SV has a reference count of one, so
203if all your code does is create SVs then store them in a hash, hv_store
204will own the only reference to the new SV, and your code doesn't need to do
205anything further to tidy up. hv_store is not implemented as a call to
206hv_store_ent, and does not create a temporary SV for the key, so if your
207key data is not already in SV form then use hv_store in preference to
208hv_store_ent.
209
210See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
211information on how to use this function on tied hashes.
212
213=cut
214*/
215
216SV**
217Perl_hv_store(pTHX_ HV *hv, const char *key, I32 klen_i32, SV *val, U32 hash)
218{
219 HE *hek;
220 STRLEN klen;
221 int flags;
222
223 if (klen_i32 < 0) {
224 klen = -klen_i32;
225 flags = HVhek_UTF8;
226 } else {
227 klen = klen_i32;
228 flags = 0;
229 }
230 hek = hv_fetch_common (hv, NULL, key, klen, flags,
52d01cc2 231 (HV_FETCH_ISSTORE|HV_FETCH_JUST_SV), val, hash);
34a6f7b4
NC
232 return hek ? &HeVAL(hek) : NULL;
233}
234
235SV**
236Perl_hv_store_flags(pTHX_ HV *hv, const char *key, I32 klen, SV *val,
237 register U32 hash, int flags)
238{
239 HE *hek = hv_fetch_common (hv, NULL, key, klen, flags,
240 (HV_FETCH_ISSTORE|HV_FETCH_JUST_SV), val, hash);
241 return hek ? &HeVAL(hek) : NULL;
242}
243
244/*
245=for apidoc hv_store_ent
246
247Stores C<val> in a hash. The hash key is specified as C<key>. The C<hash>
248parameter is the precomputed hash value; if it is zero then Perl will
249compute it. The return value is the new hash entry so created. It will be
250NULL if the operation failed or if the value did not need to be actually
251stored within the hash (as in the case of tied hashes). Otherwise the
252contents of the return value can be accessed using the C<He?> macros
253described here. Note that the caller is responsible for suitably
254incrementing the reference count of C<val> before the call, and
255decrementing it if the function returned NULL. Effectively a successful
256hv_store_ent takes ownership of one reference to C<val>. This is
257usually what you want; a newly created SV has a reference count of one, so
258if all your code does is create SVs then store them in a hash, hv_store
259will own the only reference to the new SV, and your code doesn't need to do
260anything further to tidy up. Note that hv_store_ent only reads the C<key>;
261unlike C<val> it does not take ownership of it, so maintaining the correct
262reference count on C<key> is entirely the caller's responsibility. hv_store
263is not implemented as a call to hv_store_ent, and does not create a temporary
264SV for the key, so if your key data is not already in SV form then use
265hv_store in preference to hv_store_ent.
266
267See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
268information on how to use this function on tied hashes.
269
270=cut
271*/
272
273HE *
274Perl_hv_store_ent(pTHX_ HV *hv, SV *keysv, SV *val, U32 hash)
275{
276 return hv_fetch_common(hv, keysv, NULL, 0, 0, HV_FETCH_ISSTORE, val, hash);
277}
278
279/*
280=for apidoc hv_exists
281
282Returns a boolean indicating whether the specified hash key exists. The
283C<klen> is the length of the key.
284
285=cut
286*/
287
288bool
289Perl_hv_exists(pTHX_ HV *hv, const char *key, I32 klen_i32)
290{
291 STRLEN klen;
292 int flags;
293
294 if (klen_i32 < 0) {
295 klen = -klen_i32;
296 flags = HVhek_UTF8;
297 } else {
298 klen = klen_i32;
299 flags = 0;
300 }
301 return hv_fetch_common(hv, NULL, key, klen, flags, HV_FETCH_ISEXISTS, 0, 0)
302 ? TRUE : FALSE;
303}
304
954c1994
GS
305/*
306=for apidoc hv_fetch
307
308Returns the SV which corresponds to the specified key in the hash. The
309C<klen> is the length of the key. If C<lval> is set then the fetch will be
310part of a store. Check that the return value is non-null before
d1be9408 311dereferencing it to an C<SV*>.
954c1994 312
96f1132b 313See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
954c1994
GS
314information on how to use this function on tied hashes.
315
316=cut
317*/
318
79072805 319SV**
c1fe5510 320Perl_hv_fetch(pTHX_ HV *hv, const char *key, I32 klen_i32, I32 lval)
79072805 321{
c1fe5510
NC
322 HE *hek;
323 STRLEN klen;
324 int flags;
325
326 if (klen_i32 < 0) {
327 klen = -klen_i32;
328 flags = HVhek_UTF8;
329 } else {
330 klen = klen_i32;
331 flags = 0;
332 }
333 hek = hv_fetch_common (hv, NULL, key, klen, flags,
b2c64049
NC
334 HV_FETCH_JUST_SV | (lval ? HV_FETCH_LVALUE : 0),
335 Nullsv, 0);
113738bb 336 return hek ? &HeVAL(hek) : NULL;
79072805
LW
337}
338
34a6f7b4
NC
339/*
340=for apidoc hv_exists_ent
341
342Returns a boolean indicating whether the specified hash key exists. C<hash>
343can be a valid precomputed hash value, or 0 to ask for it to be
344computed.
345
346=cut
347*/
348
349bool
350Perl_hv_exists_ent(pTHX_ HV *hv, SV *keysv, U32 hash)
351{
352 return hv_fetch_common(hv, keysv, NULL, 0, 0, HV_FETCH_ISEXISTS, 0, hash)
353 ? TRUE : FALSE;
354}
355
d1be9408 356/* returns an HE * structure with the all fields set */
fde52b5c 357/* note that hent_val will be a mortal sv for MAGICAL hashes */
954c1994
GS
358/*
359=for apidoc hv_fetch_ent
360
361Returns the hash entry which corresponds to the specified key in the hash.
362C<hash> must be a valid precomputed hash number for the given C<key>, or 0
363if you want the function to compute it. IF C<lval> is set then the fetch
364will be part of a store. Make sure the return value is non-null before
365accessing it. The return value when C<tb> is a tied hash is a pointer to a
366static location, so be sure to make a copy of the structure if you need to
1c846c1f 367store it somewhere.
954c1994 368
96f1132b 369See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
954c1994
GS
370information on how to use this function on tied hashes.
371
372=cut
373*/
374
fde52b5c 375HE *
864dbfa3 376Perl_hv_fetch_ent(pTHX_ HV *hv, SV *keysv, I32 lval, register U32 hash)
fde52b5c 377{
7f66fda2 378 return hv_fetch_common(hv, keysv, NULL, 0, 0,
b2c64049 379 (lval ? HV_FETCH_LVALUE : 0), Nullsv, hash);
113738bb
NC
380}
381
8f8d40ab 382STATIC HE *
c1fe5510 383S_hv_fetch_common(pTHX_ HV *hv, SV *keysv, const char *key, STRLEN klen,
b2c64049 384 int flags, int action, SV *val, register U32 hash)
113738bb 385{
b2c64049
NC
386 XPVHV* xhv;
387 U32 n_links;
388 HE *entry;
389 HE **oentry;
fde52b5c 390 SV *sv;
da58a35d 391 bool is_utf8;
113738bb 392 int masked_flags;
fde52b5c
PP
393
394 if (!hv)
395 return 0;
396
113738bb 397 if (keysv) {
e593d2fe
AE
398 if (flags & HVhek_FREEKEY)
399 Safefree(key);
113738bb 400 key = SvPV(keysv, klen);
c1fe5510 401 flags = 0;
113738bb
NC
402 is_utf8 = (SvUTF8(keysv) != 0);
403 } else {
c1fe5510 404 is_utf8 = ((flags & HVhek_UTF8) ? TRUE : FALSE);
113738bb 405 }
113738bb 406
b2c64049 407 xhv = (XPVHV*)SvANY(hv);
7f66fda2
NC
408 if (SvMAGICAL(hv)) {
409 if (SvRMAGICAL(hv) && !(action & (HV_FETCH_ISSTORE|HV_FETCH_ISEXISTS)))
410 {
411 if (mg_find((SV*)hv, PERL_MAGIC_tied) || SvGMAGICAL((SV*)hv)) {
412 sv = sv_newmortal();
113738bb 413
7f66fda2
NC
414 /* XXX should be able to skimp on the HE/HEK here when
415 HV_FETCH_JUST_SV is true. */
113738bb 416
7f66fda2
NC
417 if (!keysv) {
418 keysv = newSVpvn(key, klen);
419 if (is_utf8) {
420 SvUTF8_on(keysv);
421 }
422 } else {
423 keysv = newSVsv(keysv);
113738bb 424 }
7f66fda2
NC
425 mg_copy((SV*)hv, sv, (char *)keysv, HEf_SVKEY);
426
427 /* grab a fake HE/HEK pair from the pool or make a new one */
428 entry = PL_hv_fetch_ent_mh;
429 if (entry)
430 PL_hv_fetch_ent_mh = HeNEXT(entry);
431 else {
432 char *k;
433 entry = new_HE();
434 New(54, k, HEK_BASESIZE + sizeof(SV*), char);
435 HeKEY_hek(entry) = (HEK*)k;
436 }
437 HeNEXT(entry) = Nullhe;
438 HeSVKEY_set(entry, keysv);
439 HeVAL(entry) = sv;
440 sv_upgrade(sv, SVt_PVLV);
441 LvTYPE(sv) = 'T';
442 /* so we can free entry when freeing sv */
443 LvTARG(sv) = (SV*)entry;
444
445 /* XXX remove at some point? */
446 if (flags & HVhek_FREEKEY)
447 Safefree(key);
448
449 return entry;
113738bb 450 }
7f66fda2
NC
451#ifdef ENV_IS_CASELESS
452 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
453 U32 i;
454 for (i = 0; i < klen; ++i)
455 if (isLOWER(key[i])) {
086cb327
NC
456 /* Would be nice if we had a routine to do the
457 copy and upercase in a single pass through. */
458 char *nkey = strupr(savepvn(key,klen));
459 /* Note that this fetch is for nkey (the uppercased
460 key) whereas the store is for key (the original) */
461 entry = hv_fetch_common(hv, Nullsv, nkey, klen,
462 HVhek_FREEKEY, /* free nkey */
463 0 /* non-LVAL fetch */,
464 Nullsv /* no value */,
465 0 /* compute hash */);
466 if (!entry && (action & HV_FETCH_LVALUE)) {
467 /* This call will free key if necessary.
468 Do it this way to encourage compiler to tail
469 call optimise. */
470 entry = hv_fetch_common(hv, keysv, key, klen,
471 flags, HV_FETCH_ISSTORE,
472 NEWSV(61,0), hash);
473 } else {
474 if (flags & HVhek_FREEKEY)
475 Safefree(key);
476 }
477 return entry;
7f66fda2 478 }
902173a3 479 }
7f66fda2
NC
480#endif
481 } /* ISFETCH */
482 else if (SvRMAGICAL(hv) && (action & HV_FETCH_ISEXISTS)) {
483 if (mg_find((SV*)hv, PERL_MAGIC_tied) || SvGMAGICAL((SV*)hv)) {
484 SV* svret;
b2c64049
NC
485 /* I don't understand why hv_exists_ent has svret and sv,
486 whereas hv_exists only had one. */
487 svret = sv_newmortal();
488 sv = sv_newmortal();
7f66fda2
NC
489
490 if (keysv || is_utf8) {
491 if (!keysv) {
492 keysv = newSVpvn(key, klen);
493 SvUTF8_on(keysv);
494 } else {
495 keysv = newSVsv(keysv);
496 }
b2c64049
NC
497 mg_copy((SV*)hv, sv, (char *)sv_2mortal(keysv), HEf_SVKEY);
498 } else {
499 mg_copy((SV*)hv, sv, key, klen);
7f66fda2 500 }
b2c64049
NC
501 if (flags & HVhek_FREEKEY)
502 Safefree(key);
7f66fda2
NC
503 magic_existspack(svret, mg_find(sv, PERL_MAGIC_tiedelem));
504 /* This cast somewhat evil, but I'm merely using NULL/
505 not NULL to return the boolean exists.
506 And I know hv is not NULL. */
507 return SvTRUE(svret) ? (HE *)hv : NULL;
e7152ba2 508 }
7f66fda2
NC
509#ifdef ENV_IS_CASELESS
510 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
511 /* XXX This code isn't UTF8 clean. */
b2c64049
NC
512 const char *keysave = key;
513 /* Will need to free this, so set FREEKEY flag. */
514 key = savepvn(key,klen);
515 key = (const char*)strupr((char*)key);
7f66fda2
NC
516 is_utf8 = 0;
517 hash = 0;
8b4f7dd5 518 keysv = 0;
b2c64049
NC
519
520 if (flags & HVhek_FREEKEY) {
521 Safefree(keysave);
522 }
523 flags |= HVhek_FREEKEY;
7f66fda2 524 }
902173a3 525#endif
7f66fda2 526 } /* ISEXISTS */
b2c64049
NC
527 else if (action & HV_FETCH_ISSTORE) {
528 bool needs_copy;
529 bool needs_store;
530 hv_magic_check (hv, &needs_copy, &needs_store);
531 if (needs_copy) {
532 bool save_taint = PL_tainted;
533 if (keysv || is_utf8) {
534 if (!keysv) {
535 keysv = newSVpvn(key, klen);
536 SvUTF8_on(keysv);
537 }
538 if (PL_tainting)
539 PL_tainted = SvTAINTED(keysv);
540 keysv = sv_2mortal(newSVsv(keysv));
541 mg_copy((SV*)hv, val, (char*)keysv, HEf_SVKEY);
542 } else {
543 mg_copy((SV*)hv, val, key, klen);
544 }
545
546 TAINT_IF(save_taint);
547 if (!xhv->xhv_array /* !HvARRAY(hv) */ && !needs_store) {
548 if (flags & HVhek_FREEKEY)
549 Safefree(key);
550 return Nullhe;
551 }
552#ifdef ENV_IS_CASELESS
553 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
554 /* XXX This code isn't UTF8 clean. */
555 const char *keysave = key;
556 /* Will need to free this, so set FREEKEY flag. */
557 key = savepvn(key,klen);
558 key = (const char*)strupr((char*)key);
559 is_utf8 = 0;
560 hash = 0;
8b4f7dd5 561 keysv = 0;
b2c64049
NC
562
563 if (flags & HVhek_FREEKEY) {
564 Safefree(keysave);
565 }
566 flags |= HVhek_FREEKEY;
567 }
568#endif
569 }
570 } /* ISSTORE */
7f66fda2 571 } /* SvMAGICAL */
fde52b5c 572
cbec9347 573 if (!xhv->xhv_array /* !HvARRAY(hv) */) {
b2c64049 574 if ((action & (HV_FETCH_LVALUE | HV_FETCH_ISSTORE))
fde52b5c 575#ifdef DYNAMIC_ENV_FETCH /* if it's an %ENV lookup, we may get it on the fly */
8aacddc1 576 || (SvRMAGICAL((SV*)hv) && mg_find((SV*)hv, PERL_MAGIC_env))
fde52b5c 577#endif
8aacddc1 578 )
cbec9347
JH
579 Newz(503, xhv->xhv_array /* HvARRAY(hv) */,
580 PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */),
581 char);
7f66fda2
NC
582#ifdef DYNAMIC_ENV_FETCH
583 else if (action & HV_FETCH_ISEXISTS) {
584 /* for an %ENV exists, if we do an insert it's by a recursive
585 store call, so avoid creating HvARRAY(hv) right now. */
586 }
587#endif
113738bb
NC
588 else {
589 /* XXX remove at some point? */
590 if (flags & HVhek_FREEKEY)
591 Safefree(key);
592
fde52b5c 593 return 0;
113738bb 594 }
fde52b5c
PP
595 }
596
19692e8d 597 if (is_utf8) {
7f66fda2 598 const char *keysave = key;
f9a63242 599 key = (char*)bytes_from_utf8((U8*)key, &klen, &is_utf8);
19692e8d 600 if (is_utf8)
c1fe5510
NC
601 flags |= HVhek_UTF8;
602 else
603 flags &= ~HVhek_UTF8;
7f66fda2
NC
604 if (key != keysave) {
605 if (flags & HVhek_FREEKEY)
606 Safefree(keysave);
19692e8d 607 flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
7f66fda2 608 }
19692e8d 609 }
f9a63242 610
4b5190b5
NC
611 if (HvREHASH(hv)) {
612 PERL_HASH_INTERNAL(hash, key, klen);
b2c64049
NC
613 /* We don't have a pointer to the hv, so we have to replicate the
614 flag into every HEK, so that hv_iterkeysv can see it. */
615 /* And yes, you do need this even though you are not "storing" because
fdcd69b6
NC
616 you can flip the flags below if doing an lval lookup. (And that
617 was put in to give the semantics Andreas was expecting.) */
618 flags |= HVhek_REHASH;
4b5190b5 619 } else if (!hash) {
113738bb 620 if (keysv && (SvIsCOW_shared_hash(keysv))) {
46187eeb
NC
621 hash = SvUVX(keysv);
622 } else {
623 PERL_HASH(hash, key, klen);
624 }
625 }
effa1e2d 626
113738bb 627 masked_flags = (flags & HVhek_MASK);
b2c64049 628 n_links = 0;
113738bb 629
7f66fda2
NC
630#ifdef DYNAMIC_ENV_FETCH
631 if (!xhv->xhv_array /* !HvARRAY(hv) */) entry = Null(HE*);
632 else
633#endif
b2c64049 634 {
ab4af705
NC
635 /* entry = (HvARRAY(hv))[hash & (I32) HvMAX(hv)]; */
636 entry = ((HE**)xhv->xhv_array)[hash & (I32) xhv->xhv_max];
b2c64049
NC
637 }
638 for (; entry; ++n_links, entry = HeNEXT(entry)) {
fde52b5c
PP
639 if (HeHASH(entry) != hash) /* strings can't be equal */
640 continue;
eb160463 641 if (HeKLEN(entry) != (I32)klen)
fde52b5c 642 continue;
1c846c1f 643 if (HeKEY(entry) != key && memNE(HeKEY(entry),key,klen)) /* is this it? */
fde52b5c 644 continue;
113738bb 645 if ((HeKFLAGS(entry) ^ masked_flags) & HVhek_UTF8)
c3654f1a 646 continue;
b2c64049
NC
647
648 if (action & (HV_FETCH_LVALUE|HV_FETCH_ISSTORE)) {
649 if (HeKFLAGS(entry) != masked_flags) {
650 /* We match if HVhek_UTF8 bit in our flags and hash key's
651 match. But if entry was set previously with HVhek_WASUTF8
652 and key now doesn't (or vice versa) then we should change
653 the key's flag, as this is assignment. */
654 if (HvSHAREKEYS(hv)) {
655 /* Need to swap the key we have for a key with the flags we
656 need. As keys are shared we can't just write to the
657 flag, so we share the new one, unshare the old one. */
658 HEK *new_hek = share_hek_flags(key, klen, hash,
659 masked_flags);
660 unshare_hek (HeKEY_hek(entry));
661 HeKEY_hek(entry) = new_hek;
662 }
663 else
664 HeKFLAGS(entry) = masked_flags;
665 if (masked_flags & HVhek_ENABLEHVKFLAGS)
666 HvHASKFLAGS_on(hv);
667 }
668 if (HeVAL(entry) == &PL_sv_placeholder) {
669 /* yes, can store into placeholder slot */
670 if (action & HV_FETCH_LVALUE) {
671 if (SvMAGICAL(hv)) {
672 /* This preserves behaviour with the old hv_fetch
673 implementation which at this point would bail out
674 with a break; (at "if we find a placeholder, we
675 pretend we haven't found anything")
676
677 That break mean that if a placeholder were found, it
678 caused a call into hv_store, which in turn would
679 check magic, and if there is no magic end up pretty
680 much back at this point (in hv_store's code). */
681 break;
682 }
683 /* LVAL fetch which actaully needs a store. */
684 val = NEWSV(61,0);
685 xhv->xhv_placeholders--;
686 } else {
687 /* store */
688 if (val != &PL_sv_placeholder)
689 xhv->xhv_placeholders--;
690 }
691 HeVAL(entry) = val;
692 } else if (action & HV_FETCH_ISSTORE) {
693 SvREFCNT_dec(HeVAL(entry));
694 HeVAL(entry) = val;
695 }
27bcc0a7 696 } else if (HeVAL(entry) == &PL_sv_placeholder) {
b2c64049
NC
697 /* if we find a placeholder, we pretend we haven't found
698 anything */
8aacddc1 699 break;
b2c64049 700 }
113738bb
NC
701 if (flags & HVhek_FREEKEY)
702 Safefree(key);
fde52b5c
PP
703 return entry;
704 }
705#ifdef DYNAMIC_ENV_FETCH /* %ENV lookup? If so, try to fetch the value now */
0ed29950
NC
706 if (!(action & HV_FETCH_ISSTORE)
707 && SvRMAGICAL((SV*)hv) && mg_find((SV*)hv, PERL_MAGIC_env)) {
a6c40364
GS
708 unsigned long len;
709 char *env = PerlEnv_ENVgetenv_len(key,&len);
710 if (env) {
711 sv = newSVpvn(env,len);
712 SvTAINTED_on(sv);
7fd3d16e 713 return hv_fetch_common(hv,keysv,key,klen,flags,HV_FETCH_ISSTORE,sv,
b2c64049 714 hash);
a6c40364 715 }
fde52b5c
PP
716 }
717#endif
7f66fda2
NC
718
719 if (!entry && SvREADONLY(hv) && !(action & HV_FETCH_ISEXISTS)) {
2393f1b9
JH
720 S_hv_notallowed(aTHX_ flags, key, klen,
721 "access disallowed key '%"SVf"' in"
722 );
1b1f1335 723 }
b2c64049
NC
724 if (!(action & (HV_FETCH_LVALUE|HV_FETCH_ISSTORE))) {
725 /* Not doing some form of store, so return failure. */
726 if (flags & HVhek_FREEKEY)
727 Safefree(key);
728 return 0;
729 }
113738bb 730 if (action & HV_FETCH_LVALUE) {
b2c64049
NC
731 val = NEWSV(61,0);
732 if (SvMAGICAL(hv)) {
733 /* At this point the old hv_fetch code would call to hv_store,
734 which in turn might do some tied magic. So we need to make that
735 magic check happen. */
736 /* gonna assign to this, so it better be there */
737 return hv_fetch_common(hv, keysv, key, klen, flags,
738 HV_FETCH_ISSTORE, val, hash);
739 /* XXX Surely that could leak if the fetch-was-store fails?
740 Just like the hv_fetch. */
113738bb
NC
741 }
742 }
743
b2c64049
NC
744 /* Welcome to hv_store... */
745
ab4af705 746 if (!xhv->xhv_array) {
b2c64049
NC
747 /* Not sure if we can get here. I think the only case of oentry being
748 NULL is for %ENV with dynamic env fetch. But that should disappear
749 with magic in the previous code. */
750 Newz(503, xhv->xhv_array /* HvARRAY(hv) */,
751 PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */),
752 char);
b2c64049
NC
753 }
754
ab4af705
NC
755 oentry = &((HE**)xhv->xhv_array)[hash & (I32) xhv->xhv_max];
756
b2c64049
NC
757 entry = new_HE();
758 /* share_hek_flags will do the free for us. This might be considered
759 bad API design. */
760 if (HvSHAREKEYS(hv))
761 HeKEY_hek(entry) = share_hek_flags(key, klen, hash, flags);
762 else /* gotta do the real thing */
763 HeKEY_hek(entry) = save_hek_flags(key, klen, hash, flags);
764 HeVAL(entry) = val;
765 HeNEXT(entry) = *oentry;
766 *oentry = entry;
767
768 if (val == &PL_sv_placeholder)
769 xhv->xhv_placeholders++;
770 if (masked_flags & HVhek_ENABLEHVKFLAGS)
771 HvHASKFLAGS_on(hv);
772
773 xhv->xhv_keys++; /* HvKEYS(hv)++ */
774 if (!n_links) { /* initial entry? */
775 xhv->xhv_fill++; /* HvFILL(hv)++ */
776 } else if ((xhv->xhv_keys > (IV)xhv->xhv_max)
777 || ((n_links > HV_MAX_LENGTH_BEFORE_SPLIT) && !HvREHASH(hv))) {
778 /* Use only the old HvKEYS(hv) > HvMAX(hv) condition to limit bucket
779 splits on a rehashed hash, as we're not going to split it again,
780 and if someone is lucky (evil) enough to get all the keys in one
781 list they could exhaust our memory as we repeatedly double the
782 number of buckets on every entry. Linear search feels a less worse
783 thing to do. */
784 hsplit(hv);
fde52b5c 785 }
b2c64049
NC
786
787 return entry;
fde52b5c
PP
788}
789
864dbfa3 790STATIC void
cea2e8a9 791S_hv_magic_check(pTHX_ HV *hv, bool *needs_copy, bool *needs_store)
d0066dc7
OT
792{
793 MAGIC *mg = SvMAGIC(hv);
794 *needs_copy = FALSE;
795 *needs_store = TRUE;
796 while (mg) {
797 if (isUPPER(mg->mg_type)) {
798 *needs_copy = TRUE;
799 switch (mg->mg_type) {
14befaf4
DM
800 case PERL_MAGIC_tied:
801 case PERL_MAGIC_sig:
d0066dc7 802 *needs_store = FALSE;
d0066dc7
OT
803 }
804 }
805 mg = mg->mg_moremagic;
806 }
807}
808
954c1994 809/*
a3bcc51e
TP
810=for apidoc hv_scalar
811
812Evaluates the hash in scalar context and returns the result. Handles magic when the hash is tied.
813
814=cut
815*/
816
817SV *
818Perl_hv_scalar(pTHX_ HV *hv)
819{
820 MAGIC *mg;
821 SV *sv;
822
823 if ((SvRMAGICAL(hv) && (mg = mg_find((SV*)hv, PERL_MAGIC_tied)))) {
824 sv = magic_scalarpack(hv, mg);
825 return sv;
826 }
827
828 sv = sv_newmortal();
829 if (HvFILL((HV*)hv))
830 Perl_sv_setpvf(aTHX_ sv, "%ld/%ld",
831 (long)HvFILL(hv), (long)HvMAX(hv) + 1);
832 else
833 sv_setiv(sv, 0);
834
835 return sv;
836}
837
838/*
954c1994
GS
839=for apidoc hv_delete
840
841Deletes a key/value pair in the hash. The value SV is removed from the
1c846c1f 842hash and returned to the caller. The C<klen> is the length of the key.
954c1994
GS
843The C<flags> value will normally be zero; if set to G_DISCARD then NULL
844will be returned.
845
846=cut
847*/
848
79072805 849SV *
cd6d36ac 850Perl_hv_delete(pTHX_ HV *hv, const char *key, I32 klen_i32, I32 flags)
79072805 851{
cd6d36ac
NC
852 STRLEN klen;
853 int k_flags = 0;
854
855 if (klen_i32 < 0) {
856 klen = -klen_i32;
857 k_flags |= HVhek_UTF8;
858 } else {
859 klen = klen_i32;
860 }
861 return hv_delete_common(hv, NULL, key, klen, k_flags, flags, 0);
fde52b5c
PP
862}
863
954c1994
GS
864/*
865=for apidoc hv_delete_ent
866
867Deletes a key/value pair in the hash. The value SV is removed from the
868hash and returned to the caller. The C<flags> value will normally be zero;
869if set to G_DISCARD then NULL will be returned. C<hash> can be a valid
870precomputed hash value, or 0 to ask for it to be computed.
871
872=cut
873*/
874
fde52b5c 875SV *
864dbfa3 876Perl_hv_delete_ent(pTHX_ HV *hv, SV *keysv, I32 flags, U32 hash)
fde52b5c 877{
cd6d36ac 878 return hv_delete_common(hv, keysv, NULL, 0, 0, flags, hash);
f1317c8d
NC
879}
880
8f8d40ab 881STATIC SV *
cd6d36ac
NC
882S_hv_delete_common(pTHX_ HV *hv, SV *keysv, const char *key, STRLEN klen,
883 int k_flags, I32 d_flags, U32 hash)
f1317c8d 884{
cbec9347 885 register XPVHV* xhv;
fde52b5c 886 register I32 i;
fde52b5c
PP
887 register HE *entry;
888 register HE **oentry;
889 SV *sv;
da58a35d 890 bool is_utf8;
7a9669ca 891 int masked_flags;
1c846c1f 892
fde52b5c
PP
893 if (!hv)
894 return Nullsv;
f1317c8d
NC
895
896 if (keysv) {
e593d2fe
AE
897 if (k_flags & HVhek_FREEKEY)
898 Safefree(key);
f1317c8d 899 key = SvPV(keysv, klen);
cd6d36ac 900 k_flags = 0;
f1317c8d
NC
901 is_utf8 = (SvUTF8(keysv) != 0);
902 } else {
cd6d36ac 903 is_utf8 = ((k_flags & HVhek_UTF8) ? TRUE : FALSE);
f1317c8d 904 }
f1317c8d 905
fde52b5c 906 if (SvRMAGICAL(hv)) {
0a0bb7c7
OT
907 bool needs_copy;
908 bool needs_store;
909 hv_magic_check (hv, &needs_copy, &needs_store);
910
f1317c8d 911 if (needs_copy) {
7a9669ca
NC
912 entry = hv_fetch_common(hv, keysv, key, klen,
913 k_flags & ~HVhek_FREEKEY, HV_FETCH_LVALUE,
b2c64049 914 Nullsv, hash);
7a9669ca 915 sv = entry ? HeVAL(entry) : NULL;
f1317c8d
NC
916 if (sv) {
917 if (SvMAGICAL(sv)) {
918 mg_clear(sv);
919 }
920 if (!needs_store) {
921 if (mg_find(sv, PERL_MAGIC_tiedelem)) {
922 /* No longer an element */
923 sv_unmagic(sv, PERL_MAGIC_tiedelem);
924 return sv;
925 }
926 return Nullsv; /* element cannot be deleted */
927 }
902173a3 928#ifdef ENV_IS_CASELESS
8167a60a
NC
929 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
930 /* XXX This code isn't UTF8 clean. */
931 keysv = sv_2mortal(newSVpvn(key,klen));
932 if (k_flags & HVhek_FREEKEY) {
933 Safefree(key);
934 }
935 key = strupr(SvPVX(keysv));
936 is_utf8 = 0;
937 k_flags = 0;
938 hash = 0;
7f66fda2 939 }
510ac311 940#endif
2fd1c6b8 941 }
2fd1c6b8 942 }
fde52b5c 943 }
cbec9347
JH
944 xhv = (XPVHV*)SvANY(hv);
945 if (!xhv->xhv_array /* !HvARRAY(hv) */)
fde52b5c
PP
946 return Nullsv;
947
19692e8d 948 if (is_utf8) {
7f66fda2
NC
949 const char *keysave = key;
950 key = (char*)bytes_from_utf8((U8*)key, &klen, &is_utf8);
cd6d36ac 951
19692e8d 952 if (is_utf8)
cd6d36ac
NC
953 k_flags |= HVhek_UTF8;
954 else
955 k_flags &= ~HVhek_UTF8;
7f66fda2
NC
956 if (key != keysave) {
957 if (k_flags & HVhek_FREEKEY) {
958 /* This shouldn't happen if our caller does what we expect,
959 but strictly the API allows it. */
960 Safefree(keysave);
961 }
962 k_flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
963 }
cd6d36ac 964 HvHASKFLAGS_on((SV*)hv);
19692e8d 965 }
f9a63242 966
4b5190b5
NC
967 if (HvREHASH(hv)) {
968 PERL_HASH_INTERNAL(hash, key, klen);
969 } else if (!hash) {
7a9669ca
NC
970 if (keysv && (SvIsCOW_shared_hash(keysv))) {
971 hash = SvUVX(keysv);
972 } else {
973 PERL_HASH(hash, key, klen);
974 }
4b5190b5 975 }
fde52b5c 976
7a9669ca
NC
977 masked_flags = (k_flags & HVhek_MASK);
978
cbec9347
JH
979 /* oentry = &(HvARRAY(hv))[hash & (I32) HvMAX(hv)]; */
980 oentry = &((HE**)xhv->xhv_array)[hash & (I32) xhv->xhv_max];
fde52b5c
PP
981 entry = *oentry;
982 i = 1;
983 for (; entry; i=0, oentry = &HeNEXT(entry), entry = *oentry) {
984 if (HeHASH(entry) != hash) /* strings can't be equal */
985 continue;
eb160463 986 if (HeKLEN(entry) != (I32)klen)
fde52b5c 987 continue;
1c846c1f 988 if (HeKEY(entry) != key && memNE(HeKEY(entry),key,klen)) /* is this it? */
fde52b5c 989 continue;
7a9669ca 990 if ((HeKFLAGS(entry) ^ masked_flags) & HVhek_UTF8)
c3654f1a 991 continue;
8aacddc1
NIS
992
993 /* if placeholder is here, it's already been deleted.... */
7996736c 994 if (HeVAL(entry) == &PL_sv_placeholder)
8aacddc1 995 {
b84d0860
NC
996 if (k_flags & HVhek_FREEKEY)
997 Safefree(key);
998 return Nullsv;
8aacddc1
NIS
999 }
1000 else if (SvREADONLY(hv) && HeVAL(entry) && SvREADONLY(HeVAL(entry))) {
2393f1b9
JH
1001 S_hv_notallowed(aTHX_ k_flags, key, klen,
1002 "delete readonly key '%"SVf"' from"
1003 );
8aacddc1 1004 }
b84d0860
NC
1005 if (k_flags & HVhek_FREEKEY)
1006 Safefree(key);
8aacddc1 1007
cd6d36ac 1008 if (d_flags & G_DISCARD)
fde52b5c 1009 sv = Nullsv;
94f7643d 1010 else {
79d01fbf 1011 sv = sv_2mortal(HeVAL(entry));
7996736c 1012 HeVAL(entry) = &PL_sv_placeholder;
94f7643d 1013 }
8aacddc1
NIS
1014
1015 /*
1016 * If a restricted hash, rather than really deleting the entry, put
1017 * a placeholder there. This marks the key as being "approved", so
1018 * we can still access via not-really-existing key without raising
1019 * an error.
1020 */
1021 if (SvREADONLY(hv)) {
754604c4 1022 SvREFCNT_dec(HeVAL(entry));
7996736c 1023 HeVAL(entry) = &PL_sv_placeholder;
8aacddc1
NIS
1024 /* We'll be saving this slot, so the number of allocated keys
1025 * doesn't go down, but the number placeholders goes up */
1026 xhv->xhv_placeholders++; /* HvPLACEHOLDERS(hv)++ */
1027 } else {
a26e96df
NIS
1028 *oentry = HeNEXT(entry);
1029 if (i && !*oentry)
1030 xhv->xhv_fill--; /* HvFILL(hv)-- */
8aacddc1
NIS
1031 if (entry == xhv->xhv_eiter /* HvEITER(hv) */)
1032 HvLAZYDEL_on(hv);
1033 else
1034 hv_free_ent(hv, entry);
1035 xhv->xhv_keys--; /* HvKEYS(hv)-- */
574c8022 1036 if (xhv->xhv_keys == 0)
19692e8d 1037 HvHASKFLAGS_off(hv);
8aacddc1 1038 }
79072805
LW
1039 return sv;
1040 }
8aacddc1 1041 if (SvREADONLY(hv)) {
2393f1b9
JH
1042 S_hv_notallowed(aTHX_ k_flags, key, klen,
1043 "delete disallowed key '%"SVf"' from"
1044 );
8aacddc1
NIS
1045 }
1046
19692e8d 1047 if (k_flags & HVhek_FREEKEY)
f9a63242 1048 Safefree(key);
79072805 1049 return Nullsv;
79072805
LW
1050}
1051
76e3520e 1052STATIC void
cea2e8a9 1053S_hsplit(pTHX_ HV *hv)
79072805 1054{
cbec9347
JH
1055 register XPVHV* xhv = (XPVHV*)SvANY(hv);
1056 I32 oldsize = (I32) xhv->xhv_max+1; /* HvMAX(hv)+1 (sick) */
79072805
LW
1057 register I32 newsize = oldsize * 2;
1058 register I32 i;
cbec9347 1059 register char *a = xhv->xhv_array; /* HvARRAY(hv) */
72311751
GS
1060 register HE **aep;
1061 register HE **bep;
79072805
LW
1062 register HE *entry;
1063 register HE **oentry;
4b5190b5
NC
1064 int longest_chain = 0;
1065 int was_shared;
79072805 1066
18026298
NC
1067 /*PerlIO_printf(PerlIO_stderr(), "hsplit called for %p which had %d\n",
1068 hv, (int) oldsize);*/
1069
1070 if (HvPLACEHOLDERS(hv) && !SvREADONLY(hv)) {
1071 /* Can make this clear any placeholders first for non-restricted hashes,
1072 even though Storable rebuilds restricted hashes by putting in all the
1073 placeholders (first) before turning on the readonly flag, because
1074 Storable always pre-splits the hash. */
1075 hv_clear_placeholders(hv);
1076 }
1077
3280af22 1078 PL_nomemok = TRUE;
8d6dde3e 1079#if defined(STRANGE_MALLOC) || defined(MYMALLOC)
d18c6117 1080 Renew(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize), char);
422a93e5 1081 if (!a) {
4a33f861 1082 PL_nomemok = FALSE;
422a93e5
GA
1083 return;
1084 }
4633a7c4 1085#else
d18c6117 1086 New(2, a, PERL_HV_ARRAY_ALLOC_BYTES(newsize), char);
422a93e5 1087 if (!a) {
3280af22 1088 PL_nomemok = FALSE;
422a93e5
GA
1089 return;
1090 }
cbec9347 1091 Copy(xhv->xhv_array /* HvARRAY(hv) */, a, oldsize * sizeof(HE*), char);
fba3b22e 1092 if (oldsize >= 64) {
cbec9347
JH
1093 offer_nice_chunk(xhv->xhv_array /* HvARRAY(hv) */,
1094 PERL_HV_ARRAY_ALLOC_BYTES(oldsize));
4633a7c4
LW
1095 }
1096 else
cbec9347 1097 Safefree(xhv->xhv_array /* HvARRAY(hv) */);
4633a7c4
LW
1098#endif
1099
3280af22 1100 PL_nomemok = FALSE;
72311751 1101 Zero(&a[oldsize * sizeof(HE*)], (newsize-oldsize) * sizeof(HE*), char); /* zero 2nd half*/
cbec9347
JH
1102 xhv->xhv_max = --newsize; /* HvMAX(hv) = --newsize */
1103 xhv->xhv_array = a; /* HvARRAY(hv) = a */
72311751 1104 aep = (HE**)a;
79072805 1105
72311751 1106 for (i=0; i<oldsize; i++,aep++) {
4b5190b5
NC
1107 int left_length = 0;
1108 int right_length = 0;
1109
72311751 1110 if (!*aep) /* non-existent */
79072805 1111 continue;
72311751
GS
1112 bep = aep+oldsize;
1113 for (oentry = aep, entry = *aep; entry; entry = *oentry) {
eb160463 1114 if ((HeHASH(entry) & newsize) != (U32)i) {
fde52b5c 1115 *oentry = HeNEXT(entry);
72311751
GS
1116 HeNEXT(entry) = *bep;
1117 if (!*bep)
cbec9347 1118 xhv->xhv_fill++; /* HvFILL(hv)++ */
72311751 1119 *bep = entry;
4b5190b5 1120 right_length++;
79072805
LW
1121 continue;
1122 }
4b5190b5 1123 else {
fde52b5c 1124 oentry = &HeNEXT(entry);
4b5190b5
NC
1125 left_length++;
1126 }
79072805 1127 }
72311751 1128 if (!*aep) /* everything moved */
cbec9347 1129 xhv->xhv_fill--; /* HvFILL(hv)-- */
4b5190b5
NC
1130 /* I think we don't actually need to keep track of the longest length,
1131 merely flag if anything is too long. But for the moment while
1132 developing this code I'll track it. */
1133 if (left_length > longest_chain)
1134 longest_chain = left_length;
1135 if (right_length > longest_chain)
1136 longest_chain = right_length;
1137 }
1138
1139
1140 /* Pick your policy for "hashing isn't working" here: */
fdcd69b6 1141 if (longest_chain <= HV_MAX_LENGTH_BEFORE_SPLIT /* split worked? */
4b5190b5
NC
1142 || HvREHASH(hv)) {
1143 return;
79072805 1144 }
4b5190b5
NC
1145
1146 if (hv == PL_strtab) {
1147 /* Urg. Someone is doing something nasty to the string table.
1148 Can't win. */
1149 return;
1150 }
1151
1152 /* Awooga. Awooga. Pathological data. */
fdcd69b6 1153 /*PerlIO_printf(PerlIO_stderr(), "%p %d of %d with %d/%d buckets\n", hv,
4b5190b5
NC
1154 longest_chain, HvTOTALKEYS(hv), HvFILL(hv), 1+HvMAX(hv));*/
1155
1156 ++newsize;
1157 Newz(2, a, PERL_HV_ARRAY_ALLOC_BYTES(newsize), char);
1158 was_shared = HvSHAREKEYS(hv);
1159
1160 xhv->xhv_fill = 0;
1161 HvSHAREKEYS_off(hv);
1162 HvREHASH_on(hv);
1163
1164 aep = (HE **) xhv->xhv_array;
1165
1166 for (i=0; i<newsize; i++,aep++) {
1167 entry = *aep;
1168 while (entry) {
1169 /* We're going to trash this HE's next pointer when we chain it
1170 into the new hash below, so store where we go next. */
1171 HE *next = HeNEXT(entry);
1172 UV hash;
1173
1174 /* Rehash it */
1175 PERL_HASH_INTERNAL(hash, HeKEY(entry), HeKLEN(entry));
1176
1177 if (was_shared) {
1178 /* Unshare it. */
1179 HEK *new_hek
1180 = save_hek_flags(HeKEY(entry), HeKLEN(entry),
1181 hash, HeKFLAGS(entry));
1182 unshare_hek (HeKEY_hek(entry));
1183 HeKEY_hek(entry) = new_hek;
1184 } else {
1185 /* Not shared, so simply write the new hash in. */
1186 HeHASH(entry) = hash;
1187 }
1188 /*PerlIO_printf(PerlIO_stderr(), "%d ", HeKFLAGS(entry));*/
1189 HEK_REHASH_on(HeKEY_hek(entry));
1190 /*PerlIO_printf(PerlIO_stderr(), "%d\n", HeKFLAGS(entry));*/
1191
1192 /* Copy oentry to the correct new chain. */
1193 bep = ((HE**)a) + (hash & (I32) xhv->xhv_max);
1194 if (!*bep)
1195 xhv->xhv_fill++; /* HvFILL(hv)++ */
1196 HeNEXT(entry) = *bep;
1197 *bep = entry;
1198
1199 entry = next;
1200 }
1201 }
1202 Safefree (xhv->xhv_array);
1203 xhv->xhv_array = a; /* HvARRAY(hv) = a */
79072805
LW
1204}
1205
72940dca 1206void
864dbfa3 1207Perl_hv_ksplit(pTHX_ HV *hv, IV newmax)
72940dca 1208{
cbec9347
JH
1209 register XPVHV* xhv = (XPVHV*)SvANY(hv);
1210 I32 oldsize = (I32) xhv->xhv_max+1; /* HvMAX(hv)+1 (sick) */
72940dca
PP
1211 register I32 newsize;
1212 register I32 i;
1213 register I32 j;
72311751
GS
1214 register char *a;
1215 register HE **aep;
72940dca
PP
1216 register HE *entry;
1217 register HE **oentry;
1218
1219 newsize = (I32) newmax; /* possible truncation here */
1220 if (newsize != newmax || newmax <= oldsize)
1221 return;
1222 while ((newsize & (1 + ~newsize)) != newsize) {
1223 newsize &= ~(newsize & (1 + ~newsize)); /* get proper power of 2 */
1224 }
1225 if (newsize < newmax)
1226 newsize *= 2;
1227 if (newsize < newmax)
1228 return; /* overflow detection */
1229
cbec9347 1230 a = xhv->xhv_array; /* HvARRAY(hv) */
72940dca 1231 if (a) {
3280af22 1232 PL_nomemok = TRUE;
8d6dde3e 1233#if defined(STRANGE_MALLOC) || defined(MYMALLOC)
d18c6117 1234 Renew(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize), char);
8aacddc1 1235 if (!a) {
4a33f861 1236 PL_nomemok = FALSE;
422a93e5
GA
1237 return;
1238 }
72940dca 1239#else
d18c6117 1240 New(2, a, PERL_HV_ARRAY_ALLOC_BYTES(newsize), char);
8aacddc1 1241 if (!a) {
3280af22 1242 PL_nomemok = FALSE;
422a93e5
GA
1243 return;
1244 }
cbec9347 1245 Copy(xhv->xhv_array /* HvARRAY(hv) */, a, oldsize * sizeof(HE*), char);
fba3b22e 1246 if (oldsize >= 64) {
cbec9347
JH
1247 offer_nice_chunk(xhv->xhv_array /* HvARRAY(hv) */,
1248 PERL_HV_ARRAY_ALLOC_BYTES(oldsize));
72940dca
PP
1249 }
1250 else
cbec9347 1251 Safefree(xhv->xhv_array /* HvARRAY(hv) */);
72940dca 1252#endif
3280af22 1253 PL_nomemok = FALSE;
72311751 1254 Zero(&a[oldsize * sizeof(HE*)], (newsize-oldsize) * sizeof(HE*), char); /* zero 2nd half*/
72940dca
PP
1255 }
1256 else {
d18c6117 1257 Newz(0, a, PERL_HV_ARRAY_ALLOC_BYTES(newsize), char);
72940dca 1258 }
cbec9347
JH
1259 xhv->xhv_max = --newsize; /* HvMAX(hv) = --newsize */
1260 xhv->xhv_array = a; /* HvARRAY(hv) = a */
1261 if (!xhv->xhv_fill /* !HvFILL(hv) */) /* skip rest if no entries */
72940dca
PP
1262 return;
1263
72311751
GS
1264 aep = (HE**)a;
1265 for (i=0; i<oldsize; i++,aep++) {
1266 if (!*aep) /* non-existent */
72940dca 1267 continue;
72311751 1268 for (oentry = aep, entry = *aep; entry; entry = *oentry) {
72940dca
PP
1269 if ((j = (HeHASH(entry) & newsize)) != i) {
1270 j -= i;
1271 *oentry = HeNEXT(entry);
72311751 1272 if (!(HeNEXT(entry) = aep[j]))
cbec9347 1273 xhv->xhv_fill++; /* HvFILL(hv)++ */
72311751 1274 aep[j] = entry;
72940dca
PP
1275 continue;
1276 }
1277 else
1278 oentry = &HeNEXT(entry);
1279 }
72311751 1280 if (!*aep) /* everything moved */
cbec9347 1281 xhv->xhv_fill--; /* HvFILL(hv)-- */
72940dca
PP
1282 }
1283}
1284
954c1994
GS
1285/*
1286=for apidoc newHV
1287
1288Creates a new HV. The reference count is set to 1.
1289
1290=cut
1291*/
1292
79072805 1293HV *
864dbfa3 1294Perl_newHV(pTHX)
79072805
LW
1295{
1296 register HV *hv;
cbec9347 1297 register XPVHV* xhv;
79072805 1298
a0d0e21e
LW
1299 hv = (HV*)NEWSV(502,0);
1300 sv_upgrade((SV *)hv, SVt_PVHV);
cbec9347 1301 xhv = (XPVHV*)SvANY(hv);
79072805
LW
1302 SvPOK_off(hv);
1303 SvNOK_off(hv);
1c846c1f 1304#ifndef NODEFAULT_SHAREKEYS
fde52b5c 1305 HvSHAREKEYS_on(hv); /* key-sharing on by default */
1c846c1f 1306#endif
4b5190b5 1307
cbec9347
JH
1308 xhv->xhv_max = 7; /* HvMAX(hv) = 7 (start with 8 buckets) */
1309 xhv->xhv_fill = 0; /* HvFILL(hv) = 0 */
1310 xhv->xhv_pmroot = 0; /* HvPMROOT(hv) = 0 */
79072805
LW
1311 (void)hv_iterinit(hv); /* so each() will start off right */
1312 return hv;
1313}
1314
b3ac6de7 1315HV *
864dbfa3 1316Perl_newHVhv(pTHX_ HV *ohv)
b3ac6de7 1317{
b56ba0bf 1318 HV *hv = newHV();
4beac62f 1319 STRLEN hv_max, hv_fill;
4beac62f
AMS
1320
1321 if (!ohv || (hv_fill = HvFILL(ohv)) == 0)
1322 return hv;
4beac62f 1323 hv_max = HvMAX(ohv);
b3ac6de7 1324
b56ba0bf
AMS
1325 if (!SvMAGICAL((SV *)ohv)) {
1326 /* It's an ordinary hash, so copy it fast. AMS 20010804 */
eb160463
GS
1327 STRLEN i;
1328 bool shared = !!HvSHAREKEYS(ohv);
b56ba0bf 1329 HE **ents, **oents = (HE **)HvARRAY(ohv);
ff875642
JH
1330 char *a;
1331 New(0, a, PERL_HV_ARRAY_ALLOC_BYTES(hv_max+1), char);
1332 ents = (HE**)a;
b56ba0bf
AMS
1333
1334 /* In each bucket... */
1335 for (i = 0; i <= hv_max; i++) {
1336 HE *prev = NULL, *ent = NULL, *oent = oents[i];
1337
1338 if (!oent) {
1339 ents[i] = NULL;
1340 continue;
1341 }
1342
1343 /* Copy the linked list of entries. */
1344 for (oent = oents[i]; oent; oent = HeNEXT(oent)) {
1345 U32 hash = HeHASH(oent);
1346 char *key = HeKEY(oent);
19692e8d
NC
1347 STRLEN len = HeKLEN(oent);
1348 int flags = HeKFLAGS(oent);
b56ba0bf
AMS
1349
1350 ent = new_HE();
45dea987 1351 HeVAL(ent) = newSVsv(HeVAL(oent));
19692e8d
NC
1352 HeKEY_hek(ent)
1353 = shared ? share_hek_flags(key, len, hash, flags)
1354 : save_hek_flags(key, len, hash, flags);
b56ba0bf
AMS
1355 if (prev)
1356 HeNEXT(prev) = ent;
1357 else
1358 ents[i] = ent;
1359 prev = ent;
1360 HeNEXT(ent) = NULL;
1361 }
1362 }
1363
1364 HvMAX(hv) = hv_max;
1365 HvFILL(hv) = hv_fill;
8aacddc1 1366 HvTOTALKEYS(hv) = HvTOTALKEYS(ohv);
b56ba0bf 1367 HvARRAY(hv) = ents;
1c846c1f 1368 }
b56ba0bf
AMS
1369 else {
1370 /* Iterate over ohv, copying keys and values one at a time. */
b3ac6de7 1371 HE *entry;
b56ba0bf
AMS
1372 I32 riter = HvRITER(ohv);
1373 HE *eiter = HvEITER(ohv);
1374
1375 /* Can we use fewer buckets? (hv_max is always 2^n-1) */
1376 while (hv_max && hv_max + 1 >= hv_fill * 2)
1377 hv_max = hv_max / 2;
1378 HvMAX(hv) = hv_max;
1379
4a76a316 1380 hv_iterinit(ohv);
e16e2ff8 1381 while ((entry = hv_iternext_flags(ohv, 0))) {
19692e8d
NC
1382 hv_store_flags(hv, HeKEY(entry), HeKLEN(entry),
1383 newSVsv(HeVAL(entry)), HeHASH(entry),
1384 HeKFLAGS(entry));
b3ac6de7 1385 }
b56ba0bf
AMS
1386 HvRITER(ohv) = riter;
1387 HvEITER(ohv) = eiter;
b3ac6de7 1388 }
1c846c1f 1389
b3ac6de7
IZ
1390 return hv;
1391}
1392
79072805 1393void
864dbfa3 1394Perl_hv_free_ent(pTHX_ HV *hv, register HE *entry)
79072805 1395{
16bdeea2
GS
1396 SV *val;
1397
68dc0745 1398 if (!entry)
79072805 1399 return;
16bdeea2 1400 val = HeVAL(entry);
257c9e5b 1401 if (val && isGV(val) && GvCVu(val) && HvNAME(hv))
3280af22 1402 PL_sub_generation++; /* may be deletion of method from stash */
16bdeea2 1403 SvREFCNT_dec(val);
68dc0745
PP
1404 if (HeKLEN(entry) == HEf_SVKEY) {
1405 SvREFCNT_dec(HeKEY_sv(entry));
8aacddc1 1406 Safefree(HeKEY_hek(entry));
44a8e56a
PP
1407 }
1408 else if (HvSHAREKEYS(hv))
68dc0745 1409 unshare_hek(HeKEY_hek(entry));
fde52b5c 1410 else
68dc0745 1411 Safefree(HeKEY_hek(entry));
d33b2eba 1412 del_HE(entry);
79072805
LW
1413}
1414
1415void
864dbfa3 1416Perl_hv_delayfree_ent(pTHX_ HV *hv, register HE *entry)
79072805 1417{
68dc0745 1418 if (!entry)
79072805 1419 return;
68dc0745 1420 if (isGV(HeVAL(entry)) && GvCVu(HeVAL(entry)) && HvNAME(hv))
3280af22 1421 PL_sub_generation++; /* may be deletion of method from stash */
68dc0745
PP
1422 sv_2mortal(HeVAL(entry)); /* free between statements */
1423 if (HeKLEN(entry) == HEf_SVKEY) {
1424 sv_2mortal(HeKEY_sv(entry));
1425 Safefree(HeKEY_hek(entry));
44a8e56a
PP
1426 }
1427 else if (HvSHAREKEYS(hv))
68dc0745 1428 unshare_hek(HeKEY_hek(entry));
fde52b5c 1429 else
68dc0745 1430 Safefree(HeKEY_hek(entry));
d33b2eba 1431 del_HE(entry);
79072805
LW
1432}
1433
954c1994
GS
1434/*
1435=for apidoc hv_clear
1436
1437Clears a hash, making it empty.
1438
1439=cut
1440*/
1441
79072805 1442void
864dbfa3 1443Perl_hv_clear(pTHX_ HV *hv)
79072805 1444{
cbec9347 1445 register XPVHV* xhv;
79072805
LW
1446 if (!hv)
1447 return;
49293501 1448
ecae49c0
NC
1449 DEBUG_A(Perl_hv_assert(aTHX_ hv));
1450
34c3c4e3
DM
1451 xhv = (XPVHV*)SvANY(hv);
1452
5f099cb0 1453 if (SvREADONLY(hv) && xhv->xhv_array != NULL) {
34c3c4e3 1454 /* restricted hash: convert all keys to placeholders */
3a676441
JH
1455 I32 i;
1456 HE* entry;
1457 for (i = 0; i <= (I32) xhv->xhv_max; i++) {
1458 entry = ((HE**)xhv->xhv_array)[i];
1459 for (; entry; entry = HeNEXT(entry)) {
1460 /* not already placeholder */
7996736c 1461 if (HeVAL(entry) != &PL_sv_placeholder) {
3a676441
JH
1462 if (HeVAL(entry) && SvREADONLY(HeVAL(entry))) {
1463 SV* keysv = hv_iterkeysv(entry);
1464 Perl_croak(aTHX_
1465 "Attempt to delete readonly key '%"SVf"' from a restricted hash",
1466 keysv);
1467 }
1468 SvREFCNT_dec(HeVAL(entry));
7996736c 1469 HeVAL(entry) = &PL_sv_placeholder;
3a676441
JH
1470 xhv->xhv_placeholders++; /* HvPLACEHOLDERS(hv)++ */
1471 }
34c3c4e3
DM
1472 }
1473 }
df8c6964 1474 goto reset;
49293501
MS
1475 }
1476
463ee0b2 1477 hfreeentries(hv);
8aacddc1 1478 xhv->xhv_placeholders = 0; /* HvPLACEHOLDERS(hv) = 0 */
cbec9347
JH
1479 if (xhv->xhv_array /* HvARRAY(hv) */)
1480 (void)memzero(xhv->xhv_array /* HvARRAY(hv) */,
1481 (xhv->xhv_max+1 /* HvMAX(hv)+1 */) * sizeof(HE*));
a0d0e21e
LW
1482
1483 if (SvRMAGICAL(hv))
1c846c1f 1484 mg_clear((SV*)hv);
574c8022 1485
19692e8d 1486 HvHASKFLAGS_off(hv);
bb443f97 1487 HvREHASH_off(hv);
df8c6964
TP
1488 reset:
1489 HvEITER(hv) = NULL;
79072805
LW
1490}
1491
3540d4ce
AB
1492/*
1493=for apidoc hv_clear_placeholders
1494
1495Clears any placeholders from a hash. If a restricted hash has any of its keys
1496marked as readonly and the key is subsequently deleted, the key is not actually
1497deleted but is marked by assigning it a value of &PL_sv_placeholder. This tags
1498it so it will be ignored by future operations such as iterating over the hash,
4cdaeff7 1499but will still allow the hash to have a value reassigned to the key at some
3540d4ce
AB
1500future point. This function clears any such placeholder keys from the hash.
1501See Hash::Util::lock_keys() for an example of its use.
1502
1503=cut
1504*/
1505
1506void
1507Perl_hv_clear_placeholders(pTHX_ HV *hv)
1508{
d3677389
NC
1509 I32 items = (I32)HvPLACEHOLDERS(hv);
1510 I32 i = HvMAX(hv);
1511
1512 if (items == 0)
1513 return;
1514
1515 do {
1516 /* Loop down the linked list heads */
1517 int first = 1;
1518 HE **oentry = &(HvARRAY(hv))[i];
1519 HE *entry = *oentry;
1520
1521 if (!entry)
1522 continue;
1523
213ce8b3 1524 for (; entry; entry = *oentry) {
d3677389
NC
1525 if (HeVAL(entry) == &PL_sv_placeholder) {
1526 *oentry = HeNEXT(entry);
1527 if (first && !*oentry)
1528 HvFILL(hv)--; /* This linked list is now empty. */
1529 if (HvEITER(hv))
1530 HvLAZYDEL_on(hv);
1531 else
1532 hv_free_ent(hv, entry);
1533
1534 if (--items == 0) {
1535 /* Finished. */
1536 HvTOTALKEYS(hv) -= HvPLACEHOLDERS(hv);
1537 if (HvKEYS(hv) == 0)
1538 HvHASKFLAGS_off(hv);
1539 HvPLACEHOLDERS(hv) = 0;
1540 return;
1541 }
213ce8b3
NC
1542 } else {
1543 oentry = &HeNEXT(entry);
1544 first = 0;
d3677389
NC
1545 }
1546 }
1547 } while (--i >= 0);
1548 /* You can't get here, hence assertion should always fail. */
1549 assert (items == 0);
1550 assert (0);
3540d4ce
AB
1551}
1552
76e3520e 1553STATIC void
cea2e8a9 1554S_hfreeentries(pTHX_ HV *hv)
79072805 1555{
a0d0e21e 1556 register HE **array;
68dc0745
PP
1557 register HE *entry;
1558 register HE *oentry = Null(HE*);
a0d0e21e
LW
1559 I32 riter;
1560 I32 max;
79072805
LW
1561
1562 if (!hv)
1563 return;
a0d0e21e 1564 if (!HvARRAY(hv))
79072805 1565 return;
a0d0e21e
LW
1566
1567 riter = 0;
1568 max = HvMAX(hv);
1569 array = HvARRAY(hv);
2f86008e
DM
1570 /* make everyone else think the array is empty, so that the destructors
1571 * called for freed entries can't recusively mess with us */
1572 HvARRAY(hv) = Null(HE**);
1573 HvFILL(hv) = 0;
1574 ((XPVHV*) SvANY(hv))->xhv_keys = 0;
1575
68dc0745 1576 entry = array[0];
a0d0e21e 1577 for (;;) {
68dc0745
PP
1578 if (entry) {
1579 oentry = entry;
1580 entry = HeNEXT(entry);
1581 hv_free_ent(hv, oentry);
a0d0e21e 1582 }
68dc0745 1583 if (!entry) {
a0d0e21e
LW
1584 if (++riter > max)
1585 break;
68dc0745 1586 entry = array[riter];
1c846c1f 1587 }
79072805 1588 }
2f86008e 1589 HvARRAY(hv) = array;
a0d0e21e 1590 (void)hv_iterinit(hv);
79072805
LW
1591}
1592
954c1994
GS
1593/*
1594=for apidoc hv_undef
1595
1596Undefines the hash.
1597
1598=cut
1599*/
1600
79072805 1601void
864dbfa3 1602Perl_hv_undef(pTHX_ HV *hv)
79072805 1603{
cbec9347 1604 register XPVHV* xhv;
79072805
LW
1605 if (!hv)
1606 return;
ecae49c0 1607 DEBUG_A(Perl_hv_assert(aTHX_ hv));
cbec9347 1608 xhv = (XPVHV*)SvANY(hv);
463ee0b2 1609 hfreeentries(hv);
cbec9347 1610 Safefree(xhv->xhv_array /* HvARRAY(hv) */);
85e6fe83 1611 if (HvNAME(hv)) {
7e8961ec
AB
1612 if(PL_stashcache)
1613 hv_delete(PL_stashcache, HvNAME(hv), strlen(HvNAME(hv)), G_DISCARD);
85e6fe83
LW
1614 Safefree(HvNAME(hv));
1615 HvNAME(hv) = 0;
1616 }
cbec9347
JH
1617 xhv->xhv_max = 7; /* HvMAX(hv) = 7 (it's a normal hash) */
1618 xhv->xhv_array = 0; /* HvARRAY(hv) = 0 */
8aacddc1 1619 xhv->xhv_placeholders = 0; /* HvPLACEHOLDERS(hv) = 0 */
a0d0e21e
LW
1620
1621 if (SvRMAGICAL(hv))
1c846c1f 1622 mg_clear((SV*)hv);
79072805
LW
1623}
1624
954c1994
GS
1625/*
1626=for apidoc hv_iterinit
1627
1628Prepares a starting point to traverse a hash table. Returns the number of
1629keys in the hash (i.e. the same as C<HvKEYS(tb)>). The return value is
1c846c1f 1630currently only meaningful for hashes without tie magic.
954c1994
GS
1631
1632NOTE: Before version 5.004_65, C<hv_iterinit> used to return the number of
1633hash buckets that happen to be in use. If you still need that esoteric
1634value, you can get it through the macro C<HvFILL(tb)>.
1635
e16e2ff8 1636
954c1994
GS
1637=cut
1638*/
1639
79072805 1640I32
864dbfa3 1641Perl_hv_iterinit(pTHX_ HV *hv)
79072805 1642{
cbec9347 1643 register XPVHV* xhv;
aa689395
PP
1644 HE *entry;
1645
1646 if (!hv)
cea2e8a9 1647 Perl_croak(aTHX_ "Bad hash");
cbec9347
JH
1648 xhv = (XPVHV*)SvANY(hv);
1649 entry = xhv->xhv_eiter; /* HvEITER(hv) */
72940dca
PP
1650 if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */
1651 HvLAZYDEL_off(hv);
68dc0745 1652 hv_free_ent(hv, entry);
72940dca 1653 }
cbec9347
JH
1654 xhv->xhv_riter = -1; /* HvRITER(hv) = -1 */
1655 xhv->xhv_eiter = Null(HE*); /* HvEITER(hv) = Null(HE*) */
1656 /* used to be xhv->xhv_fill before 5.004_65 */
8aacddc1 1657 return XHvTOTALKEYS(xhv);
79072805 1658}
954c1994
GS
1659/*
1660=for apidoc hv_iternext
1661
1662Returns entries from a hash iterator. See C<hv_iterinit>.
1663
fe7bca90
NC
1664You may call C<hv_delete> or C<hv_delete_ent> on the hash entry that the
1665iterator currently points to, without losing your place or invalidating your
1666iterator. Note that in this case the current entry is deleted from the hash
1667with your iterator holding the last reference to it. Your iterator is flagged
1668to free the entry on the next call to C<hv_iternext>, so you must not discard
1669your iterator immediately else the entry will leak - call C<hv_iternext> to
1670trigger the resource deallocation.
1671
954c1994
GS
1672=cut
1673*/
1674
79072805 1675HE *
864dbfa3 1676Perl_hv_iternext(pTHX_ HV *hv)
79072805 1677{
e16e2ff8
NC
1678 return hv_iternext_flags(hv, 0);
1679}
1680
1681/*
fe7bca90
NC
1682=for apidoc hv_iternext_flags
1683
1684Returns entries from a hash iterator. See C<hv_iterinit> and C<hv_iternext>.
1685The C<flags> value will normally be zero; if HV_ITERNEXT_WANTPLACEHOLDERS is
1686set the placeholders keys (for restricted hashes) will be returned in addition
1687to normal keys. By default placeholders are automatically skipped over.
7996736c
MHM
1688Currently a placeholder is implemented with a value that is
1689C<&Perl_sv_placeholder>. Note that the implementation of placeholders and
fe7bca90
NC
1690restricted hashes may change, and the implementation currently is
1691insufficiently abstracted for any change to be tidy.
e16e2ff8 1692
fe7bca90 1693=cut
e16e2ff8
NC
1694*/
1695
1696HE *
1697Perl_hv_iternext_flags(pTHX_ HV *hv, I32 flags)
1698{
cbec9347 1699 register XPVHV* xhv;
79072805 1700 register HE *entry;
a0d0e21e 1701 HE *oldentry;
463ee0b2 1702 MAGIC* mg;
79072805
LW
1703
1704 if (!hv)
cea2e8a9 1705 Perl_croak(aTHX_ "Bad hash");
cbec9347
JH
1706 xhv = (XPVHV*)SvANY(hv);
1707 oldentry = entry = xhv->xhv_eiter; /* HvEITER(hv) */
463ee0b2 1708
14befaf4 1709 if ((mg = SvTIED_mg((SV*)hv, PERL_MAGIC_tied))) {
8990e307 1710 SV *key = sv_newmortal();
cd1469e6 1711 if (entry) {
fde52b5c 1712 sv_setsv(key, HeSVKEY_force(entry));
cd1469e6
PP
1713 SvREFCNT_dec(HeSVKEY(entry)); /* get rid of previous key */
1714 }
a0d0e21e 1715 else {
ff68c719 1716 char *k;
bbce6d69 1717 HEK *hek;
ff68c719 1718
cbec9347
JH
1719 /* one HE per MAGICAL hash */
1720 xhv->xhv_eiter = entry = new_HE(); /* HvEITER(hv) = new_HE() */
4633a7c4 1721 Zero(entry, 1, HE);
ff68c719
PP
1722 Newz(54, k, HEK_BASESIZE + sizeof(SV*), char);
1723 hek = (HEK*)k;
1724 HeKEY_hek(entry) = hek;
fde52b5c 1725 HeKLEN(entry) = HEf_SVKEY;
a0d0e21e
LW
1726 }
1727 magic_nextpack((SV*) hv,mg,key);
8aacddc1 1728 if (SvOK(key)) {
cd1469e6 1729 /* force key to stay around until next time */
bbce6d69
PP
1730 HeSVKEY_set(entry, SvREFCNT_inc(key));
1731 return entry; /* beware, hent_val is not set */
8aacddc1 1732 }
fde52b5c
PP
1733 if (HeVAL(entry))
1734 SvREFCNT_dec(HeVAL(entry));
ff68c719 1735 Safefree(HeKEY_hek(entry));
d33b2eba 1736 del_HE(entry);
cbec9347 1737 xhv->xhv_eiter = Null(HE*); /* HvEITER(hv) = Null(HE*) */
463ee0b2 1738 return Null(HE*);
79072805 1739 }
f675dbe5 1740#ifdef DYNAMIC_ENV_FETCH /* set up %ENV for iteration */
cbec9347 1741 if (!entry && SvRMAGICAL((SV*)hv) && mg_find((SV*)hv, PERL_MAGIC_env))
f675dbe5
CB
1742 prime_env_iter();
1743#endif
463ee0b2 1744
cbec9347
JH
1745 if (!xhv->xhv_array /* !HvARRAY(hv) */)
1746 Newz(506, xhv->xhv_array /* HvARRAY(hv) */,
1747 PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */),
1748 char);
015a5f36 1749 /* At start of hash, entry is NULL. */
fde52b5c 1750 if (entry)
8aacddc1 1751 {
fde52b5c 1752 entry = HeNEXT(entry);
e16e2ff8
NC
1753 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
1754 /*
1755 * Skip past any placeholders -- don't want to include them in
1756 * any iteration.
1757 */
7996736c 1758 while (entry && HeVAL(entry) == &PL_sv_placeholder) {
e16e2ff8
NC
1759 entry = HeNEXT(entry);
1760 }
8aacddc1
NIS
1761 }
1762 }
fde52b5c 1763 while (!entry) {
015a5f36
NC
1764 /* OK. Come to the end of the current list. Grab the next one. */
1765
cbec9347 1766 xhv->xhv_riter++; /* HvRITER(hv)++ */
eb160463 1767 if (xhv->xhv_riter > (I32)xhv->xhv_max /* HvRITER(hv) > HvMAX(hv) */) {
015a5f36 1768 /* There is no next one. End of the hash. */
cbec9347 1769 xhv->xhv_riter = -1; /* HvRITER(hv) = -1 */
fde52b5c 1770 break;
79072805 1771 }
cbec9347
JH
1772 /* entry = (HvARRAY(hv))[HvRITER(hv)]; */
1773 entry = ((HE**)xhv->xhv_array)[xhv->xhv_riter];
8aacddc1 1774
e16e2ff8 1775 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
015a5f36
NC
1776 /* If we have an entry, but it's a placeholder, don't count it.
1777 Try the next. */
7996736c 1778 while (entry && HeVAL(entry) == &PL_sv_placeholder)
015a5f36
NC
1779 entry = HeNEXT(entry);
1780 }
1781 /* Will loop again if this linked list starts NULL
1782 (for HV_ITERNEXT_WANTPLACEHOLDERS)
1783 or if we run through it and find only placeholders. */
fde52b5c 1784 }
79072805 1785
72940dca
PP
1786 if (oldentry && HvLAZYDEL(hv)) { /* was deleted earlier? */
1787 HvLAZYDEL_off(hv);
68dc0745 1788 hv_free_ent(hv, oldentry);
72940dca 1789 }
a0d0e21e 1790
fdcd69b6
NC
1791 /*if (HvREHASH(hv) && entry && !HeKREHASH(entry))
1792 PerlIO_printf(PerlIO_stderr(), "Awooga %p %p\n", hv, entry);*/
1793
cbec9347 1794 xhv->xhv_eiter = entry; /* HvEITER(hv) = entry */
79072805
LW
1795 return entry;
1796}
1797
954c1994
GS
1798/*
1799=for apidoc hv_iterkey
1800
1801Returns the key from the current position of the hash iterator. See
1802C<hv_iterinit>.
1803
1804=cut
1805*/
1806
79072805 1807char *
864dbfa3 1808Perl_hv_iterkey(pTHX_ register HE *entry, I32 *retlen)
79072805 1809{
fde52b5c 1810 if (HeKLEN(entry) == HEf_SVKEY) {
fb73857a
PP
1811 STRLEN len;
1812 char *p = SvPV(HeKEY_sv(entry), len);
1813 *retlen = len;
1814 return p;
fde52b5c
PP
1815 }
1816 else {
1817 *retlen = HeKLEN(entry);
1818 return HeKEY(entry);
1819 }
1820}
1821
1822/* unlike hv_iterval(), this always returns a mortal copy of the key */
954c1994
GS
1823/*
1824=for apidoc hv_iterkeysv
1825
1826Returns the key as an C<SV*> from the current position of the hash
1827iterator. The return value will always be a mortal copy of the key. Also
1828see C<hv_iterinit>.
1829
1830=cut
1831*/
1832
fde52b5c 1833SV *
864dbfa3 1834Perl_hv_iterkeysv(pTHX_ register HE *entry)
fde52b5c 1835{
19692e8d
NC
1836 if (HeKLEN(entry) != HEf_SVKEY) {
1837 HEK *hek = HeKEY_hek(entry);
1838 int flags = HEK_FLAGS(hek);
1839 SV *sv;
1840
1841 if (flags & HVhek_WASUTF8) {
1842 /* Trouble :-)
1843 Andreas would like keys he put in as utf8 to come back as utf8
1844 */
1845 STRLEN utf8_len = HEK_LEN(hek);
2e5dfef7 1846 U8 *as_utf8 = bytes_to_utf8 ((U8*)HEK_KEY(hek), &utf8_len);
19692e8d 1847
2e5dfef7 1848 sv = newSVpvn ((char*)as_utf8, utf8_len);
19692e8d 1849 SvUTF8_on (sv);
c193270f 1850 Safefree (as_utf8); /* bytes_to_utf8() allocates a new string */
4b5190b5
NC
1851 } else if (flags & HVhek_REHASH) {
1852 /* We don't have a pointer to the hv, so we have to replicate the
1853 flag into every HEK. This hv is using custom a hasing
1854 algorithm. Hence we can't return a shared string scalar, as
1855 that would contain the (wrong) hash value, and might get passed
1856 into an hv routine with a regular hash */
1857
1858 sv = newSVpvn (HEK_KEY(hek), HEK_LEN(hek));
1859 if (HEK_UTF8(hek))
1860 SvUTF8_on (sv);
1861 } else {
19692e8d
NC
1862 sv = newSVpvn_share(HEK_KEY(hek),
1863 (HEK_UTF8(hek) ? -HEK_LEN(hek) : HEK_LEN(hek)),
1864 HEK_HASH(hek));
1865 }
1866 return sv_2mortal(sv);
1867 }
1868 return sv_mortalcopy(HeKEY_sv(entry));
79072805
LW
1869}
1870
954c1994
GS
1871/*
1872=for apidoc hv_iterval
1873
1874Returns the value from the current position of the hash iterator. See
1875C<hv_iterkey>.
1876
1877=cut
1878*/
1879
79072805 1880SV *
864dbfa3 1881Perl_hv_iterval(pTHX_ HV *hv, register HE *entry)
79072805 1882{
8990e307 1883 if (SvRMAGICAL(hv)) {
14befaf4 1884 if (mg_find((SV*)hv, PERL_MAGIC_tied)) {
8990e307 1885 SV* sv = sv_newmortal();
bbce6d69
PP
1886 if (HeKLEN(entry) == HEf_SVKEY)
1887 mg_copy((SV*)hv, sv, (char*)HeKEY_sv(entry), HEf_SVKEY);
1888 else mg_copy((SV*)hv, sv, HeKEY(entry), HeKLEN(entry));
463ee0b2
LW
1889 return sv;
1890 }
79072805 1891 }
fde52b5c 1892 return HeVAL(entry);
79072805
LW
1893}
1894
954c1994
GS
1895/*
1896=for apidoc hv_iternextsv
1897
1898Performs an C<hv_iternext>, C<hv_iterkey>, and C<hv_iterval> in one
1899operation.
1900
1901=cut
1902*/
1903
a0d0e21e 1904SV *
864dbfa3 1905Perl_hv_iternextsv(pTHX_ HV *hv, char **key, I32 *retlen)
a0d0e21e
LW
1906{
1907 HE *he;
e16e2ff8 1908 if ( (he = hv_iternext_flags(hv, 0)) == NULL)
a0d0e21e
LW
1909 return NULL;
1910 *key = hv_iterkey(he, retlen);
1911 return hv_iterval(hv, he);
1912}
1913
954c1994
GS
1914/*
1915=for apidoc hv_magic
1916
1917Adds magic to a hash. See C<sv_magic>.
1918
1919=cut
1920*/
1921
79072805 1922void
864dbfa3 1923Perl_hv_magic(pTHX_ HV *hv, GV *gv, int how)
79072805 1924{
a0d0e21e 1925 sv_magic((SV*)hv, (SV*)gv, how, Nullch, 0);
79072805 1926}
fde52b5c 1927
37d85e3a
JH
1928#if 0 /* use the macro from hv.h instead */
1929
bbce6d69 1930char*
864dbfa3 1931Perl_sharepvn(pTHX_ const char *sv, I32 len, U32 hash)
bbce6d69 1932{
ff68c719 1933 return HEK_KEY(share_hek(sv, len, hash));
bbce6d69
PP
1934}
1935
37d85e3a
JH
1936#endif
1937
bbce6d69 1938/* possibly free a shared string if no one has access to it
fde52b5c
PP
1939 * len and hash must both be valid for str.
1940 */
bbce6d69 1941void
864dbfa3 1942Perl_unsharepvn(pTHX_ const char *str, I32 len, U32 hash)
fde52b5c 1943{
19692e8d
NC
1944 unshare_hek_or_pvn (NULL, str, len, hash);
1945}
1946
1947
1948void
1949Perl_unshare_hek(pTHX_ HEK *hek)
1950{
1951 unshare_hek_or_pvn(hek, NULL, 0, 0);
1952}
1953
1954/* possibly free a shared string if no one has access to it
1955 hek if non-NULL takes priority over the other 3, else str, len and hash
1956 are used. If so, len and hash must both be valid for str.
1957 */
df132699 1958STATIC void
19692e8d
NC
1959S_unshare_hek_or_pvn(pTHX_ HEK *hek, const char *str, I32 len, U32 hash)
1960{
cbec9347 1961 register XPVHV* xhv;
fde52b5c
PP
1962 register HE *entry;
1963 register HE **oentry;
1964 register I32 i = 1;
1965 I32 found = 0;
c3654f1a 1966 bool is_utf8 = FALSE;
19692e8d 1967 int k_flags = 0;
f9a63242 1968 const char *save = str;
c3654f1a 1969
19692e8d
NC
1970 if (hek) {
1971 hash = HEK_HASH(hek);
1972 } else if (len < 0) {
1973 STRLEN tmplen = -len;
1974 is_utf8 = TRUE;
1975 /* See the note in hv_fetch(). --jhi */
1976 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
1977 len = tmplen;
1978 if (is_utf8)
1979 k_flags = HVhek_UTF8;
1980 if (str != save)
1981 k_flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
c3654f1a 1982 }
1c846c1f 1983
fde52b5c 1984 /* what follows is the moral equivalent of:
6b88bc9c 1985 if ((Svp = hv_fetch(PL_strtab, tmpsv, FALSE, hash))) {
bbce6d69 1986 if (--*Svp == Nullsv)
6b88bc9c 1987 hv_delete(PL_strtab, str, len, G_DISCARD, hash);
bbce6d69 1988 } */
cbec9347 1989 xhv = (XPVHV*)SvANY(PL_strtab);
fde52b5c 1990 /* assert(xhv_array != 0) */
5f08fbcd 1991 LOCK_STRTAB_MUTEX;
cbec9347
JH
1992 /* oentry = &(HvARRAY(hv))[hash & (I32) HvMAX(hv)]; */
1993 oentry = &((HE**)xhv->xhv_array)[hash & (I32) xhv->xhv_max];
19692e8d
NC
1994 if (hek) {
1995 for (entry = *oentry; entry; i=0, oentry = &HeNEXT(entry), entry = *oentry) {
1996 if (HeKEY_hek(entry) != hek)
1997 continue;
1998 found = 1;
1999 break;
2000 }
2001 } else {
35a4481c 2002 const int flags_masked = k_flags & HVhek_MASK;
19692e8d
NC
2003 for (entry = *oentry; entry; i=0, oentry = &HeNEXT(entry), entry = *oentry) {
2004 if (HeHASH(entry) != hash) /* strings can't be equal */
2005 continue;
2006 if (HeKLEN(entry) != len)
2007 continue;
2008 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
2009 continue;
2010 if (HeKFLAGS(entry) != flags_masked)
2011 continue;
2012 found = 1;
2013 break;
2014 }
2015 }
2016
2017 if (found) {
2018 if (--HeVAL(entry) == Nullsv) {
2019 *oentry = HeNEXT(entry);
2020 if (i && !*oentry)
2021 xhv->xhv_fill--; /* HvFILL(hv)-- */
2022 Safefree(HeKEY_hek(entry));
2023 del_HE(entry);
2024 xhv->xhv_keys--; /* HvKEYS(hv)-- */
2025 }
fde52b5c 2026 }
19692e8d 2027
333f433b 2028 UNLOCK_STRTAB_MUTEX;
411caa50 2029 if (!found && ckWARN_d(WARN_INTERNAL))
19692e8d 2030 Perl_warner(aTHX_ packWARN(WARN_INTERNAL),
472d47bc
SB
2031 "Attempt to free non-existent shared string '%s'%s"
2032 pTHX__FORMAT,
19692e8d 2033 hek ? HEK_KEY(hek) : str,
472d47bc 2034 ((k_flags & HVhek_UTF8) ? " (utf8)" : "") pTHX__VALUE);
19692e8d
NC
2035 if (k_flags & HVhek_FREEKEY)
2036 Safefree(str);
fde52b5c
PP
2037}
2038
bbce6d69
PP
2039/* get a (constant) string ptr from the global string table
2040 * string will get added if it is not already there.
fde52b5c
PP
2041 * len and hash must both be valid for str.
2042 */
bbce6d69 2043HEK *
864dbfa3 2044Perl_share_hek(pTHX_ const char *str, I32 len, register U32 hash)
fde52b5c 2045{
da58a35d 2046 bool is_utf8 = FALSE;
19692e8d 2047 int flags = 0;
f9a63242 2048 const char *save = str;
da58a35d
JH
2049
2050 if (len < 0) {
77caf834 2051 STRLEN tmplen = -len;
da58a35d 2052 is_utf8 = TRUE;
77caf834
JH
2053 /* See the note in hv_fetch(). --jhi */
2054 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
2055 len = tmplen;
19692e8d
NC
2056 /* If we were able to downgrade here, then than means that we were passed
2057 in a key which only had chars 0-255, but was utf8 encoded. */
2058 if (is_utf8)
2059 flags = HVhek_UTF8;
2060 /* If we found we were able to downgrade the string to bytes, then
2061 we should flag that it needs upgrading on keys or each. Also flag
2062 that we need share_hek_flags to free the string. */
2063 if (str != save)
2064 flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
2065 }
2066
2067 return share_hek_flags (str, len, hash, flags);
2068}
2069
df132699 2070STATIC HEK *
19692e8d
NC
2071S_share_hek_flags(pTHX_ const char *str, I32 len, register U32 hash, int flags)
2072{
2073 register XPVHV* xhv;
2074 register HE *entry;
2075 register HE **oentry;
2076 register I32 i = 1;
2077 I32 found = 0;
35a4481c 2078 const int flags_masked = flags & HVhek_MASK;
bbce6d69 2079
fde52b5c 2080 /* what follows is the moral equivalent of:
1c846c1f 2081
6b88bc9c 2082 if (!(Svp = hv_fetch(PL_strtab, str, len, FALSE)))
8aacddc1 2083 hv_store(PL_strtab, str, len, Nullsv, hash);
fdcd69b6
NC
2084
2085 Can't rehash the shared string table, so not sure if it's worth
2086 counting the number of entries in the linked list
bbce6d69 2087 */
cbec9347 2088 xhv = (XPVHV*)SvANY(PL_strtab);
fde52b5c 2089 /* assert(xhv_array != 0) */
5f08fbcd 2090 LOCK_STRTAB_MUTEX;
cbec9347
JH
2091 /* oentry = &(HvARRAY(hv))[hash & (I32) HvMAX(hv)]; */
2092 oentry = &((HE**)xhv->xhv_array)[hash & (I32) xhv->xhv_max];
bbce6d69 2093 for (entry = *oentry; entry; i=0, entry = HeNEXT(entry)) {
fde52b5c
PP
2094 if (HeHASH(entry) != hash) /* strings can't be equal */
2095 continue;
2096 if (HeKLEN(entry) != len)
2097 continue;
1c846c1f 2098 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
fde52b5c 2099 continue;
19692e8d 2100 if (HeKFLAGS(entry) != flags_masked)
c3654f1a 2101 continue;
fde52b5c 2102 found = 1;
fde52b5c
PP
2103 break;
2104 }
bbce6d69 2105 if (!found) {
d33b2eba 2106 entry = new_HE();
dcf933a4 2107 HeKEY_hek(entry) = save_hek_flags(str, len, hash, flags_masked);
bbce6d69
PP
2108 HeVAL(entry) = Nullsv;
2109 HeNEXT(entry) = *oentry;
2110 *oentry = entry;
cbec9347 2111 xhv->xhv_keys++; /* HvKEYS(hv)++ */
bbce6d69 2112 if (i) { /* initial entry? */
cbec9347 2113 xhv->xhv_fill++; /* HvFILL(hv)++ */
4c9cc595 2114 } else if (xhv->xhv_keys > (IV)xhv->xhv_max /* HvKEYS(hv) > HvMAX(hv) */) {
cbec9347 2115 hsplit(PL_strtab);
bbce6d69
PP
2116 }
2117 }
2118
2119 ++HeVAL(entry); /* use value slot as REFCNT */
5f08fbcd 2120 UNLOCK_STRTAB_MUTEX;
19692e8d
NC
2121
2122 if (flags & HVhek_FREEKEY)
f9a63242 2123 Safefree(str);
19692e8d 2124
ff68c719 2125 return HeKEY_hek(entry);
fde52b5c 2126}
ecae49c0
NC
2127
2128
2129/*
2130=for apidoc hv_assert
2131
2132Check that a hash is in an internally consistent state.
2133
2134=cut
2135*/
2136
2137void
2138Perl_hv_assert(pTHX_ HV *hv)
2139{
2140 HE* entry;
2141 int withflags = 0;
2142 int placeholders = 0;
2143 int real = 0;
2144 int bad = 0;
2145 I32 riter = HvRITER(hv);
2146 HE *eiter = HvEITER(hv);
2147
2148 (void)hv_iterinit(hv);
2149
2150 while ((entry = hv_iternext_flags(hv, HV_ITERNEXT_WANTPLACEHOLDERS))) {
2151 /* sanity check the values */
2152 if (HeVAL(entry) == &PL_sv_placeholder) {
2153 placeholders++;
2154 } else {
2155 real++;
2156 }
2157 /* sanity check the keys */
2158 if (HeSVKEY(entry)) {
2159 /* Don't know what to check on SV keys. */
2160 } else if (HeKUTF8(entry)) {
2161 withflags++;
2162 if (HeKWASUTF8(entry)) {
2163 PerlIO_printf(Perl_debug_log,
2164 "hash key has both WASUFT8 and UTF8: '%.*s'\n",
2165 (int) HeKLEN(entry), HeKEY(entry));
2166 bad = 1;
2167 }
2168 } else if (HeKWASUTF8(entry)) {
2169 withflags++;
2170 }
2171 }
2172 if (!SvTIED_mg((SV*)hv, PERL_MAGIC_tied)) {
2173 if (HvUSEDKEYS(hv) != real) {
2174 PerlIO_printf(Perl_debug_log, "Count %d key(s), but hash reports %d\n",
2175 (int) real, (int) HvUSEDKEYS(hv));
2176 bad = 1;
2177 }
2178 if (HvPLACEHOLDERS(hv) != placeholders) {
2179 PerlIO_printf(Perl_debug_log,
2180 "Count %d placeholder(s), but hash reports %d\n",
2181 (int) placeholders, (int) HvPLACEHOLDERS(hv));
2182 bad = 1;
2183 }
2184 }
2185 if (withflags && ! HvHASKFLAGS(hv)) {
2186 PerlIO_printf(Perl_debug_log,
2187 "Hash has HASKFLAGS off but I count %d key(s) with flags\n",
2188 withflags);
2189 bad = 1;
2190 }
2191 if (bad) {
2192 sv_dump((SV *)hv);
2193 }
2194 HvRITER(hv) = riter; /* Restore hash iterator state */
2195 HvEITER(hv) = eiter;
2196}
af3babe4
NC
2197
2198/*
2199 * Local variables:
2200 * c-indentation-style: bsd
2201 * c-basic-offset: 4
2202 * indent-tabs-mode: t
2203 * End:
2204 *
2205 * vim: shiftwidth=4:
2206*/