1 /* hv.c
2 *
3 * Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
4 * 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008 by Larry Wall and others
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 *
9 */
10
11 /*
12 * I sit beside the fire and think
13 * of all that I have seen.
14 * --Bilbo
15 *
16 * [p.278 of _The Lord of the Rings_, II/iii: "The Ring Goes South"]
17 */
18
19 /*
20 =head1 HV Handling
21 A HV structure represents a Perl hash. It consists mainly of an array
22 of pointers, each of which points to a linked list of HE structures. The
23 array is indexed by the hash function of the key, so each linked list
24 represents all the hash entries with the same hash value. Each HE contains
25 a pointer to the actual value, plus a pointer to a HEK structure which
26 holds the key and hash value.
27
28 =cut
29
30 */
31
32 #include "EXTERN.h"
33 #define PERL_IN_HV_C
34 #define PERL_HASH_INTERNAL_ACCESS
35 #include "perl.h"
36
37 /* we split when we collide and we have a load factor over 0.667.
38 * NOTE if you change this formula so we split earlier than previously
39 * you MUST change the logic in hv_ksplit()
40 */
41
42 /* MAX_BUCKET_MAX is the maximum max bucket index, at which point we stop growing the
43 * number of buckets,
44 */
45 #define MAX_BUCKET_MAX ((1<<26)-1)
46 #define DO_HSPLIT(xhv) ( ( ((xhv)->xhv_keys + ((xhv)->xhv_keys >> 1)) > (xhv)->xhv_max ) && \
47 ((xhv)->xhv_max < MAX_BUCKET_MAX) )
48
49 static const char S_strtab_error[]
50 = "Cannot modify shared string table in hv_%s";
51
52 #ifdef PURIFY
53
54 #define new_HE() (HE*)safemalloc(sizeof(HE))
55 #define del_HE(p) safefree((char*)p)
56
57 #else
58
59 STATIC HE*
S_new_he(pTHX)60 S_new_he(pTHX)
61 {
62 HE* he;
63 void ** const root = &PL_body_roots[HE_ARENA_ROOT_IX];
64
65 if (!*root)
66 Perl_more_bodies(aTHX_ HE_ARENA_ROOT_IX, sizeof(HE), PERL_ARENA_SIZE);
67 he = (HE*) *root;
68 assert(he);
69 *root = HeNEXT(he);
70 return he;
71 }
72
73 #define new_HE() new_he()
74 #define del_HE(p) \
75 STMT_START { \
76 HeNEXT(p) = (HE*)(PL_body_roots[HE_ARENA_ROOT_IX]); \
77 PL_body_roots[HE_ARENA_ROOT_IX] = p; \
78 } STMT_END
79
80
81
82 #endif
83
84 STATIC HEK *
S_save_hek_flags(const char * str,I32 len,U32 hash,int flags)85 S_save_hek_flags(const char *str, I32 len, U32 hash, int flags)
86 {
87 const int flags_masked = flags & HVhek_MASK;
88 char *k;
89 HEK *hek;
90
91 PERL_ARGS_ASSERT_SAVE_HEK_FLAGS;
92
93 Newx(k, HEK_BASESIZE + len + 2, char);
94 hek = (HEK*)k;
95 Copy(str, HEK_KEY(hek), len, char);
96 HEK_KEY(hek)[len] = 0;
97 HEK_LEN(hek) = len;
98 HEK_HASH(hek) = hash;
99 HEK_FLAGS(hek) = (unsigned char)flags_masked | HVhek_UNSHARED;
100
101 if (flags & HVhek_FREEKEY)
102 Safefree(str);
103 return hek;
104 }
105
106 /* free the pool of temporary HE/HEK pairs returned by hv_fetch_ent
107 * for tied hashes */
108
109 void
Perl_free_tied_hv_pool(pTHX)110 Perl_free_tied_hv_pool(pTHX)
111 {
112 HE *he = PL_hv_fetch_ent_mh;
113 while (he) {
114 HE * const ohe = he;
115 Safefree(HeKEY_hek(he));
116 he = HeNEXT(he);
117 del_HE(ohe);
118 }
119 PL_hv_fetch_ent_mh = NULL;
120 }
121
122 #if defined(USE_ITHREADS)
123 HEK *
Perl_hek_dup(pTHX_ HEK * source,CLONE_PARAMS * param)124 Perl_hek_dup(pTHX_ HEK *source, CLONE_PARAMS* param)
125 {
126 HEK *shared;
127
128 PERL_ARGS_ASSERT_HEK_DUP;
129 PERL_UNUSED_ARG(param);
130
131 if (!source)
132 return NULL;
133
134 shared = (HEK*)ptr_table_fetch(PL_ptr_table, source);
135 if (shared) {
136 /* We already shared this hash key. */
137 (void)share_hek_hek(shared);
138 }
139 else {
140 shared
141 = share_hek_flags(HEK_KEY(source), HEK_LEN(source),
142 HEK_HASH(source), HEK_FLAGS(source));
143 ptr_table_store(PL_ptr_table, source, shared);
144 }
145 return shared;
146 }
147
148 HE *
Perl_he_dup(pTHX_ const HE * e,bool shared,CLONE_PARAMS * param)149 Perl_he_dup(pTHX_ const HE *e, bool shared, CLONE_PARAMS* param)
150 {
151 HE *ret;
152
153 PERL_ARGS_ASSERT_HE_DUP;
154
155 if (!e)
156 return NULL;
157 /* look for it in the table first */
158 ret = (HE*)ptr_table_fetch(PL_ptr_table, e);
159 if (ret)
160 return ret;
161
162 /* create anew and remember what it is */
163 ret = new_HE();
164 ptr_table_store(PL_ptr_table, e, ret);
165
166 HeNEXT(ret) = he_dup(HeNEXT(e),shared, param);
167 if (HeKLEN(e) == HEf_SVKEY) {
168 char *k;
169 Newx(k, HEK_BASESIZE + sizeof(const SV *), char);
170 HeKEY_hek(ret) = (HEK*)k;
171 HeKEY_sv(ret) = sv_dup_inc(HeKEY_sv(e), param);
172 }
173 else if (shared) {
174 /* This is hek_dup inlined, which seems to be important for speed
175 reasons. */
176 HEK * const source = HeKEY_hek(e);
177 HEK *shared = (HEK*)ptr_table_fetch(PL_ptr_table, source);
178
179 if (shared) {
180 /* We already shared this hash key. */
181 (void)share_hek_hek(shared);
182 }
183 else {
184 shared
185 = share_hek_flags(HEK_KEY(source), HEK_LEN(source),
186 HEK_HASH(source), HEK_FLAGS(source));
187 ptr_table_store(PL_ptr_table, source, shared);
188 }
189 HeKEY_hek(ret) = shared;
190 }
191 else
192 HeKEY_hek(ret) = save_hek_flags(HeKEY(e), HeKLEN(e), HeHASH(e),
193 HeKFLAGS(e));
194 HeVAL(ret) = sv_dup_inc(HeVAL(e), param);
195 return ret;
196 }
197 #endif /* USE_ITHREADS */
198
199 static void
S_hv_notallowed(pTHX_ int flags,const char * key,I32 klen,const char * msg)200 S_hv_notallowed(pTHX_ int flags, const char *key, I32 klen,
201 const char *msg)
202 {
203 SV * const sv = sv_newmortal();
204
205 PERL_ARGS_ASSERT_HV_NOTALLOWED;
206
207 if (!(flags & HVhek_FREEKEY)) {
208 sv_setpvn(sv, key, klen);
209 }
210 else {
211 /* Need to free saved eventually assign to mortal SV */
212 /* XXX is this line an error ???: SV *sv = sv_newmortal(); */
213 sv_usepvn(sv, (char *) key, klen);
214 }
215 if (flags & HVhek_UTF8) {
216 SvUTF8_on(sv);
217 }
218 Perl_croak(aTHX_ msg, SVfARG(sv));
219 }
220
221 /* (klen == HEf_SVKEY) is special for MAGICAL hv entries, meaning key slot
222 * contains an SV* */
223
224 /*
225 =for apidoc hv_store
226
227 Stores an SV in a hash. The hash key is specified as C<key> and the
228 absolute value of C<klen> is the length of the key. If C<klen> is
229 negative the key is assumed to be in UTF-8-encoded Unicode. The
230 C<hash> parameter is the precomputed hash value; if it is zero then
231 Perl will compute it.
232
233 The return value will be
234 C<NULL> if the operation failed or if the value did not need to be actually
235 stored within the hash (as in the case of tied hashes). Otherwise it can
236 be dereferenced to get the original C<SV*>. Note that the caller is
237 responsible for suitably incrementing the reference count of C<val> before
238 the call, and decrementing it if the function returned C<NULL>. Effectively
239 a successful C<hv_store> takes ownership of one reference to C<val>. This is
240 usually what you want; a newly created SV has a reference count of one, so
241 if all your code does is create SVs then store them in a hash, C<hv_store>
242 will own the only reference to the new SV, and your code doesn't need to do
243 anything further to tidy up. C<hv_store> is not implemented as a call to
244 C<hv_store_ent>, and does not create a temporary SV for the key, so if your
245 key data is not already in SV form then use C<hv_store> in preference to
246 C<hv_store_ent>.
247
248 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
249 information on how to use this function on tied hashes.
250
251 =for apidoc hv_store_ent
252
253 Stores C<val> in a hash. The hash key is specified as C<key>. The C<hash>
254 parameter is the precomputed hash value; if it is zero then Perl will
255 compute it. The return value is the new hash entry so created. It will be
256 C<NULL> if the operation failed or if the value did not need to be actually
257 stored within the hash (as in the case of tied hashes). Otherwise the
258 contents of the return value can be accessed using the C<He?> macros
259 described here. Note that the caller is responsible for suitably
260 incrementing the reference count of C<val> before the call, and
261 decrementing it if the function returned NULL. Effectively a successful
262 C<hv_store_ent> takes ownership of one reference to C<val>. This is
263 usually what you want; a newly created SV has a reference count of one, so
264 if all your code does is create SVs then store them in a hash, C<hv_store>
265 will own the only reference to the new SV, and your code doesn't need to do
266 anything further to tidy up. Note that C<hv_store_ent> only reads the C<key>;
267 unlike C<val> it does not take ownership of it, so maintaining the correct
268 reference count on C<key> is entirely the caller's responsibility. The reason
269 it does not take ownership, is that C<key> is not used after this function
270 returns, and so can be freed immediately. C<hv_store>
271 is not implemented as a call to C<hv_store_ent>, and does not create a temporary
272 SV for the key, so if your key data is not already in SV form then use
273 C<hv_store> in preference to C<hv_store_ent>.
274
275 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
276 information on how to use this function on tied hashes.
277
278 =for apidoc hv_exists
279
280 Returns a boolean indicating whether the specified hash key exists. The
281 absolute value of C<klen> is the length of the key. If C<klen> is
282 negative the key is assumed to be in UTF-8-encoded Unicode.
283
284 =for apidoc hv_fetch
285
286 Returns the SV which corresponds to the specified key in the hash.
287 The absolute value of C<klen> is the length of the key. If C<klen> is
288 negative the key is assumed to be in UTF-8-encoded Unicode. If
289 C<lval> is set then the fetch will be part of a store. This means that if
290 there is no value in the hash associated with the given key, then one is
291 created and a pointer to it is returned. The C<SV*> it points to can be
292 assigned to. But always check that the
293 return value is non-null before dereferencing it to an C<SV*>.
294
295 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
296 information on how to use this function on tied hashes.
297
298 =for apidoc hv_exists_ent
299
300 Returns a boolean indicating whether
301 the specified hash key exists. C<hash>
302 can be a valid precomputed hash value, or 0 to ask for it to be
303 computed.
304
305 =cut
306 */
307
308 /* returns an HE * structure with the all fields set */
309 /* note that hent_val will be a mortal sv for MAGICAL hashes */
310 /*
311 =for apidoc hv_fetch_ent
312
313 Returns the hash entry which corresponds to the specified key in the hash.
314 C<hash> must be a valid precomputed hash number for the given C<key>, or 0
315 if you want the function to compute it. IF C<lval> is set then the fetch
316 will be part of a store. Make sure the return value is non-null before
317 accessing it. The return value when C<hv> is a tied hash is a pointer to a
318 static location, so be sure to make a copy of the structure if you need to
319 store it somewhere.
320
321 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
322 information on how to use this function on tied hashes.
323
324 =cut
325 */
326
327 /* Common code for hv_delete()/hv_exists()/hv_fetch()/hv_store() */
328 void *
Perl_hv_common_key_len(pTHX_ HV * hv,const char * key,I32 klen_i32,const int action,SV * val,const U32 hash)329 Perl_hv_common_key_len(pTHX_ HV *hv, const char *key, I32 klen_i32,
330 const int action, SV *val, const U32 hash)
331 {
332 STRLEN klen;
333 int flags;
334
335 PERL_ARGS_ASSERT_HV_COMMON_KEY_LEN;
336
337 if (klen_i32 < 0) {
338 klen = -klen_i32;
339 flags = HVhek_UTF8;
340 } else {
341 klen = klen_i32;
342 flags = 0;
343 }
344 return hv_common(hv, NULL, key, klen, flags, action, val, hash);
345 }
346
347 void *
Perl_hv_common(pTHX_ HV * hv,SV * keysv,const char * key,STRLEN klen,int flags,int action,SV * val,U32 hash)348 Perl_hv_common(pTHX_ HV *hv, SV *keysv, const char *key, STRLEN klen,
349 int flags, int action, SV *val, U32 hash)
350 {
351 XPVHV* xhv;
352 HE *entry;
353 HE **oentry;
354 SV *sv;
355 bool is_utf8;
356 bool in_collision;
357 int masked_flags;
358 const int return_svp = action & HV_FETCH_JUST_SV;
359 HEK *keysv_hek = NULL;
360
361 if (!hv)
362 return NULL;
363 if (SvTYPE(hv) == (svtype)SVTYPEMASK)
364 return NULL;
365
366 assert(SvTYPE(hv) == SVt_PVHV);
367
368 if (SvSMAGICAL(hv) && SvGMAGICAL(hv) && !(action & HV_DISABLE_UVAR_XKEY)) {
369 MAGIC* mg;
370 if ((mg = mg_find((const SV *)hv, PERL_MAGIC_uvar))) {
371 struct ufuncs * const uf = (struct ufuncs *)mg->mg_ptr;
372 if (uf->uf_set == NULL) {
373 SV* obj = mg->mg_obj;
374
375 if (!keysv) {
376 keysv = newSVpvn_flags(key, klen, SVs_TEMP |
377 ((flags & HVhek_UTF8)
378 ? SVf_UTF8 : 0));
379 }
380
381 mg->mg_obj = keysv; /* pass key */
382 uf->uf_index = action; /* pass action */
383 magic_getuvar(MUTABLE_SV(hv), mg);
384 keysv = mg->mg_obj; /* may have changed */
385 mg->mg_obj = obj;
386
387 /* If the key may have changed, then we need to invalidate
388 any passed-in computed hash value. */
389 hash = 0;
390 }
391 }
392 }
393 if (keysv) {
394 if (flags & HVhek_FREEKEY)
395 Safefree(key);
396 key = SvPV_const(keysv, klen);
397 is_utf8 = (SvUTF8(keysv) != 0);
398 if (SvIsCOW_shared_hash(keysv)) {
399 flags = HVhek_KEYCANONICAL | (is_utf8 ? HVhek_UTF8 : 0);
400 } else {
401 flags = 0;
402 }
403 } else {
404 is_utf8 = cBOOL(flags & HVhek_UTF8);
405 }
406
407 if (action & HV_DELETE) {
408 return (void *) hv_delete_common(hv, keysv, key, klen,
409 flags | (is_utf8 ? HVhek_UTF8 : 0),
410 action, hash);
411 }
412
413 xhv = (XPVHV*)SvANY(hv);
414 if (SvMAGICAL(hv)) {
415 if (SvRMAGICAL(hv) && !(action & (HV_FETCH_ISSTORE|HV_FETCH_ISEXISTS))) {
416 if (mg_find((const SV *)hv, PERL_MAGIC_tied)
417 || SvGMAGICAL((const SV *)hv))
418 {
419 /* FIXME should be able to skimp on the HE/HEK here when
420 HV_FETCH_JUST_SV is true. */
421 if (!keysv) {
422 keysv = newSVpvn_utf8(key, klen, is_utf8);
423 } else {
424 keysv = newSVsv(keysv);
425 }
426 sv = sv_newmortal();
427 mg_copy(MUTABLE_SV(hv), sv, (char *)keysv, HEf_SVKEY);
428
429 /* grab a fake HE/HEK pair from the pool or make a new one */
430 entry = PL_hv_fetch_ent_mh;
431 if (entry)
432 PL_hv_fetch_ent_mh = HeNEXT(entry);
433 else {
434 char *k;
435 entry = new_HE();
436 Newx(k, HEK_BASESIZE + sizeof(const SV *), char);
437 HeKEY_hek(entry) = (HEK*)k;
438 }
439 HeNEXT(entry) = NULL;
440 HeSVKEY_set(entry, keysv);
441 HeVAL(entry) = sv;
442 sv_upgrade(sv, SVt_PVLV);
443 LvTYPE(sv) = 'T';
444 /* so we can free entry when freeing sv */
445 LvTARG(sv) = MUTABLE_SV(entry);
446
447 /* XXX remove at some point? */
448 if (flags & HVhek_FREEKEY)
449 Safefree(key);
450
451 if (return_svp) {
452 return entry ? (void *) &HeVAL(entry) : NULL;
453 }
454 return (void *) entry;
455 }
456 #ifdef ENV_IS_CASELESS
457 else if (mg_find((const SV *)hv, PERL_MAGIC_env)) {
458 U32 i;
459 for (i = 0; i < klen; ++i)
460 if (isLOWER(key[i])) {
461 /* Would be nice if we had a routine to do the
462 copy and upercase in a single pass through. */
463 const char * const nkey = strupr(savepvn(key,klen));
464 /* Note that this fetch is for nkey (the uppercased
465 key) whereas the store is for key (the original) */
466 void *result = hv_common(hv, NULL, nkey, klen,
467 HVhek_FREEKEY, /* free nkey */
468 0 /* non-LVAL fetch */
469 | HV_DISABLE_UVAR_XKEY
470 | return_svp,
471 NULL /* no value */,
472 0 /* compute hash */);
473 if (!result && (action & HV_FETCH_LVALUE)) {
474 /* This call will free key if necessary.
475 Do it this way to encourage compiler to tail
476 call optimise. */
477 result = hv_common(hv, keysv, key, klen, flags,
478 HV_FETCH_ISSTORE
479 | HV_DISABLE_UVAR_XKEY
480 | return_svp,
481 newSV(0), hash);
482 } else {
483 if (flags & HVhek_FREEKEY)
484 Safefree(key);
485 }
486 return result;
487 }
488 }
489 #endif
490 } /* ISFETCH */
491 else if (SvRMAGICAL(hv) && (action & HV_FETCH_ISEXISTS)) {
492 if (mg_find((const SV *)hv, PERL_MAGIC_tied)
493 || SvGMAGICAL((const SV *)hv)) {
494 /* I don't understand why hv_exists_ent has svret and sv,
495 whereas hv_exists only had one. */
496 SV * const svret = sv_newmortal();
497 sv = sv_newmortal();
498
499 if (keysv || is_utf8) {
500 if (!keysv) {
501 keysv = newSVpvn_utf8(key, klen, TRUE);
502 } else {
503 keysv = newSVsv(keysv);
504 }
505 mg_copy(MUTABLE_SV(hv), sv, (char *)sv_2mortal(keysv), HEf_SVKEY);
506 } else {
507 mg_copy(MUTABLE_SV(hv), sv, key, klen);
508 }
509 if (flags & HVhek_FREEKEY)
510 Safefree(key);
511 {
512 MAGIC * const mg = mg_find(sv, PERL_MAGIC_tiedelem);
513 if (mg)
514 magic_existspack(svret, mg);
515 }
516 /* This cast somewhat evil, but I'm merely using NULL/
517 not NULL to return the boolean exists.
518 And I know hv is not NULL. */
519 return SvTRUE_NN(svret) ? (void *)hv : NULL;
520 }
521 #ifdef ENV_IS_CASELESS
522 else if (mg_find((const SV *)hv, PERL_MAGIC_env)) {
523 /* XXX This code isn't UTF8 clean. */
524 char * const keysave = (char * const)key;
525 /* Will need to free this, so set FREEKEY flag. */
526 key = savepvn(key,klen);
527 key = (const char*)strupr((char*)key);
528 is_utf8 = FALSE;
529 hash = 0;
530 keysv = 0;
531
532 if (flags & HVhek_FREEKEY) {
533 Safefree(keysave);
534 }
535 flags |= HVhek_FREEKEY;
536 }
537 #endif
538 } /* ISEXISTS */
539 else if (action & HV_FETCH_ISSTORE) {
540 bool needs_copy;
541 bool needs_store;
542 hv_magic_check (hv, &needs_copy, &needs_store);
543 if (needs_copy) {
544 const bool save_taint = TAINT_get;
545 if (keysv || is_utf8) {
546 if (!keysv) {
547 keysv = newSVpvn_utf8(key, klen, TRUE);
548 }
549 if (TAINTING_get)
550 TAINT_set(SvTAINTED(keysv));
551 keysv = sv_2mortal(newSVsv(keysv));
552 mg_copy(MUTABLE_SV(hv), val, (char*)keysv, HEf_SVKEY);
553 } else {
554 mg_copy(MUTABLE_SV(hv), val, key, klen);
555 }
556
557 TAINT_IF(save_taint);
558 #ifdef NO_TAINT_SUPPORT
559 PERL_UNUSED_VAR(save_taint);
560 #endif
561 if (!needs_store) {
562 if (flags & HVhek_FREEKEY)
563 Safefree(key);
564 return NULL;
565 }
566 #ifdef ENV_IS_CASELESS
567 else if (mg_find((const SV *)hv, PERL_MAGIC_env)) {
568 /* XXX This code isn't UTF8 clean. */
569 const char *keysave = key;
570 /* Will need to free this, so set FREEKEY flag. */
571 key = savepvn(key,klen);
572 key = (const char*)strupr((char*)key);
573 is_utf8 = FALSE;
574 hash = 0;
575 keysv = 0;
576
577 if (flags & HVhek_FREEKEY) {
578 Safefree(keysave);
579 }
580 flags |= HVhek_FREEKEY;
581 }
582 #endif
583 }
584 } /* ISSTORE */
585 } /* SvMAGICAL */
586
587 if (!HvARRAY(hv)) {
588 if ((action & (HV_FETCH_LVALUE | HV_FETCH_ISSTORE))
589 #ifdef DYNAMIC_ENV_FETCH /* if it's an %ENV lookup, we may get it on the fly */
590 || (SvRMAGICAL((const SV *)hv)
591 && mg_find((const SV *)hv, PERL_MAGIC_env))
592 #endif
593 ) {
594 char *array;
595 Newxz(array,
596 PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */),
597 char);
598 HvARRAY(hv) = (HE**)array;
599 }
600 #ifdef DYNAMIC_ENV_FETCH
601 else if (action & HV_FETCH_ISEXISTS) {
602 /* for an %ENV exists, if we do an insert it's by a recursive
603 store call, so avoid creating HvARRAY(hv) right now. */
604 }
605 #endif
606 else {
607 /* XXX remove at some point? */
608 if (flags & HVhek_FREEKEY)
609 Safefree(key);
610
611 return NULL;
612 }
613 }
614
615 if (is_utf8 && !(flags & HVhek_KEYCANONICAL)) {
616 char * const keysave = (char *)key;
617 key = (char*)bytes_from_utf8((U8*)key, &klen, &is_utf8);
618 if (is_utf8)
619 flags |= HVhek_UTF8;
620 else
621 flags &= ~HVhek_UTF8;
622 if (key != keysave) {
623 if (flags & HVhek_FREEKEY)
624 Safefree(keysave);
625 flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
626 /* If the caller calculated a hash, it was on the sequence of
627 octets that are the UTF-8 form. We've now changed the sequence
628 of octets stored to that of the equivalent byte representation,
629 so the hash we need is different. */
630 hash = 0;
631 }
632 }
633
634 if (keysv && (SvIsCOW_shared_hash(keysv))) {
635 if (HvSHAREKEYS(hv))
636 keysv_hek = SvSHARED_HEK_FROM_PV(SvPVX_const(keysv));
637 hash = SvSHARED_HASH(keysv);
638 }
639 else if (!hash)
640 PERL_HASH(hash, key, klen);
641
642 masked_flags = (flags & HVhek_MASK);
643
644 #ifdef DYNAMIC_ENV_FETCH
645 if (!HvARRAY(hv)) entry = NULL;
646 else
647 #endif
648 {
649 entry = (HvARRAY(hv))[hash & (I32) HvMAX(hv)];
650 }
651
652 if (!entry)
653 goto not_found;
654
655 if (keysv_hek) {
656 /* keysv is actually a HEK in disguise, so we can match just by
657 * comparing the HEK pointers in the HE chain. There is a slight
658 * caveat: on something like "\x80", which has both plain and utf8
659 * representations, perl's hashes do encoding-insensitive lookups,
660 * but preserve the encoding of the stored key. Thus a particular
661 * key could map to two different HEKs in PL_strtab. We only
662 * conclude 'not found' if all the flags are the same; otherwise
663 * we fall back to a full search (this should only happen in rare
664 * cases).
665 */
666 int keysv_flags = HEK_FLAGS(keysv_hek);
667 HE *orig_entry = entry;
668
669 for (; entry; entry = HeNEXT(entry)) {
670 HEK *hek = HeKEY_hek(entry);
671 if (hek == keysv_hek)
672 goto found;
673 if (HEK_FLAGS(hek) != keysv_flags)
674 break; /* need to do full match */
675 }
676 if (!entry)
677 goto not_found;
678 /* failed on shortcut - do full search loop */
679 entry = orig_entry;
680 }
681
682 for (; entry; entry = HeNEXT(entry)) {
683 if (HeHASH(entry) != hash) /* strings can't be equal */
684 continue;
685 if (HeKLEN(entry) != (I32)klen)
686 continue;
687 if (memNE(HeKEY(entry),key,klen)) /* is this it? */
688 continue;
689 if ((HeKFLAGS(entry) ^ masked_flags) & HVhek_UTF8)
690 continue;
691
692 found:
693 if (action & (HV_FETCH_LVALUE|HV_FETCH_ISSTORE)) {
694 if (HeKFLAGS(entry) != masked_flags) {
695 /* We match if HVhek_UTF8 bit in our flags and hash key's
696 match. But if entry was set previously with HVhek_WASUTF8
697 and key now doesn't (or vice versa) then we should change
698 the key's flag, as this is assignment. */
699 if (HvSHAREKEYS(hv)) {
700 /* Need to swap the key we have for a key with the flags we
701 need. As keys are shared we can't just write to the
702 flag, so we share the new one, unshare the old one. */
703 HEK * const new_hek = share_hek_flags(key, klen, hash,
704 masked_flags);
705 unshare_hek (HeKEY_hek(entry));
706 HeKEY_hek(entry) = new_hek;
707 }
708 else if (hv == PL_strtab) {
709 /* PL_strtab is usually the only hash without HvSHAREKEYS,
710 so putting this test here is cheap */
711 if (flags & HVhek_FREEKEY)
712 Safefree(key);
713 Perl_croak(aTHX_ S_strtab_error,
714 action & HV_FETCH_LVALUE ? "fetch" : "store");
715 }
716 else
717 HeKFLAGS(entry) = masked_flags;
718 if (masked_flags & HVhek_ENABLEHVKFLAGS)
719 HvHASKFLAGS_on(hv);
720 }
721 if (HeVAL(entry) == &PL_sv_placeholder) {
722 /* yes, can store into placeholder slot */
723 if (action & HV_FETCH_LVALUE) {
724 if (SvMAGICAL(hv)) {
725 /* This preserves behaviour with the old hv_fetch
726 implementation which at this point would bail out
727 with a break; (at "if we find a placeholder, we
728 pretend we haven't found anything")
729
730 That break mean that if a placeholder were found, it
731 caused a call into hv_store, which in turn would
732 check magic, and if there is no magic end up pretty
733 much back at this point (in hv_store's code). */
734 break;
735 }
736 /* LVAL fetch which actually needs a store. */
737 val = newSV(0);
738 HvPLACEHOLDERS(hv)--;
739 } else {
740 /* store */
741 if (val != &PL_sv_placeholder)
742 HvPLACEHOLDERS(hv)--;
743 }
744 HeVAL(entry) = val;
745 } else if (action & HV_FETCH_ISSTORE) {
746 SvREFCNT_dec(HeVAL(entry));
747 HeVAL(entry) = val;
748 }
749 } else if (HeVAL(entry) == &PL_sv_placeholder) {
750 /* if we find a placeholder, we pretend we haven't found
751 anything */
752 break;
753 }
754 if (flags & HVhek_FREEKEY)
755 Safefree(key);
756 if (return_svp) {
757 return (void *) &HeVAL(entry);
758 }
759 return entry;
760 }
761
762 not_found:
763 #ifdef DYNAMIC_ENV_FETCH /* %ENV lookup? If so, try to fetch the value now */
764 if (!(action & HV_FETCH_ISSTORE)
765 && SvRMAGICAL((const SV *)hv)
766 && mg_find((const SV *)hv, PERL_MAGIC_env)) {
767 unsigned long len;
768 const char * const env = PerlEnv_ENVgetenv_len(key,&len);
769 if (env) {
770 sv = newSVpvn(env,len);
771 SvTAINTED_on(sv);
772 return hv_common(hv, keysv, key, klen, flags,
773 HV_FETCH_ISSTORE|HV_DISABLE_UVAR_XKEY|return_svp,
774 sv, hash);
775 }
776 }
777 #endif
778
779 if (!entry && SvREADONLY(hv) && !(action & HV_FETCH_ISEXISTS)) {
780 hv_notallowed(flags, key, klen,
781 "Attempt to access disallowed key '%" SVf "' in"
782 " a restricted hash");
783 }
784 if (!(action & (HV_FETCH_LVALUE|HV_FETCH_ISSTORE))) {
785 /* Not doing some form of store, so return failure. */
786 if (flags & HVhek_FREEKEY)
787 Safefree(key);
788 return NULL;
789 }
790 if (action & HV_FETCH_LVALUE) {
791 val = action & HV_FETCH_EMPTY_HE ? NULL : newSV(0);
792 if (SvMAGICAL(hv)) {
793 /* At this point the old hv_fetch code would call to hv_store,
794 which in turn might do some tied magic. So we need to make that
795 magic check happen. */
796 /* gonna assign to this, so it better be there */
797 /* If a fetch-as-store fails on the fetch, then the action is to
798 recurse once into "hv_store". If we didn't do this, then that
799 recursive call would call the key conversion routine again.
800 However, as we replace the original key with the converted
801 key, this would result in a double conversion, which would show
802 up as a bug if the conversion routine is not idempotent.
803 Hence the use of HV_DISABLE_UVAR_XKEY. */
804 return hv_common(hv, keysv, key, klen, flags,
805 HV_FETCH_ISSTORE|HV_DISABLE_UVAR_XKEY|return_svp,
806 val, hash);
807 /* XXX Surely that could leak if the fetch-was-store fails?
808 Just like the hv_fetch. */
809 }
810 }
811
812 /* Welcome to hv_store... */
813
814 if (!HvARRAY(hv)) {
815 /* Not sure if we can get here. I think the only case of oentry being
816 NULL is for %ENV with dynamic env fetch. But that should disappear
817 with magic in the previous code. */
818 char *array;
819 Newxz(array,
820 PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */),
821 char);
822 HvARRAY(hv) = (HE**)array;
823 }
824
825 oentry = &(HvARRAY(hv))[hash & (I32) xhv->xhv_max];
826
827 /* share_hek_flags will do the free for us. This might be considered
828 bad API design. */
829 if (LIKELY(HvSHAREKEYS(hv))) {
830 entry = new_HE();
831 HeKEY_hek(entry) = share_hek_flags(key, klen, hash, flags);
832 }
833 else if (UNLIKELY(hv == PL_strtab)) {
834 /* PL_strtab is usually the only hash without HvSHAREKEYS, so putting
835 this test here is cheap */
836 if (flags & HVhek_FREEKEY)
837 Safefree(key);
838 Perl_croak(aTHX_ S_strtab_error,
839 action & HV_FETCH_LVALUE ? "fetch" : "store");
840 }
841 else {
842 /* gotta do the real thing */
843 entry = new_HE();
844 HeKEY_hek(entry) = save_hek_flags(key, klen, hash, flags);
845 }
846 HeVAL(entry) = val;
847
848 #ifdef PERL_HASH_RANDOMIZE_KEYS
849 /* This logic semi-randomizes the insert order in a bucket.
850 * Either we insert into the top, or the slot below the top,
851 * making it harder to see if there is a collision. We also
852 * reset the iterator randomizer if there is one.
853 */
854 in_collision = *oentry != NULL;
855 if ( *oentry && PL_HASH_RAND_BITS_ENABLED) {
856 PL_hash_rand_bits++;
857 PL_hash_rand_bits= ROTL_UV(PL_hash_rand_bits,1);
858 if ( PL_hash_rand_bits & 1 ) {
859 HeNEXT(entry) = HeNEXT(*oentry);
860 HeNEXT(*oentry) = entry;
861 } else {
862 HeNEXT(entry) = *oentry;
863 *oentry = entry;
864 }
865 } else
866 #endif
867 {
868 HeNEXT(entry) = *oentry;
869 *oentry = entry;
870 }
871 #ifdef PERL_HASH_RANDOMIZE_KEYS
872 if (SvOOK(hv)) {
873 /* Currently this makes various tests warn in annoying ways.
874 * So Silenced for now. - Yves | bogus end of comment =>* /
875 if (HvAUX(hv)->xhv_riter != -1) {
876 Perl_ck_warner_d(aTHX_ packWARN(WARN_INTERNAL),
877 "[TESTING] Inserting into a hash during each() traversal results in undefined behavior"
878 pTHX__FORMAT
879 pTHX__VALUE);
880 }
881 */
882 if (PL_HASH_RAND_BITS_ENABLED) {
883 if (PL_HASH_RAND_BITS_ENABLED == 1)
884 PL_hash_rand_bits += (PTRV)entry + 1; /* we don't bother to use ptr_hash here */
885 PL_hash_rand_bits= ROTL_UV(PL_hash_rand_bits,1);
886 }
887 HvAUX(hv)->xhv_rand= (U32)PL_hash_rand_bits;
888 }
889 #endif
890
891 if (val == &PL_sv_placeholder)
892 HvPLACEHOLDERS(hv)++;
893 if (masked_flags & HVhek_ENABLEHVKFLAGS)
894 HvHASKFLAGS_on(hv);
895
896 xhv->xhv_keys++; /* HvTOTALKEYS(hv)++ */
897 if ( in_collision && DO_HSPLIT(xhv) ) {
898 const STRLEN oldsize = xhv->xhv_max + 1;
899 const U32 items = (U32)HvPLACEHOLDERS_get(hv);
900
901 if (items /* hash has placeholders */
902 && !SvREADONLY(hv) /* but is not a restricted hash */) {
903 /* If this hash previously was a "restricted hash" and had
904 placeholders, but the "restricted" flag has been turned off,
905 then the placeholders no longer serve any useful purpose.
906 However, they have the downsides of taking up RAM, and adding
907 extra steps when finding used values. It's safe to clear them
908 at this point, even though Storable rebuilds restricted hashes by
909 putting in all the placeholders (first) before turning on the
910 readonly flag, because Storable always pre-splits the hash.
911 If we're lucky, then we may clear sufficient placeholders to
912 avoid needing to split the hash at all. */
913 clear_placeholders(hv, items);
914 if (DO_HSPLIT(xhv))
915 hsplit(hv, oldsize, oldsize * 2);
916 } else
917 hsplit(hv, oldsize, oldsize * 2);
918 }
919
920 if (return_svp) {
921 return entry ? (void *) &HeVAL(entry) : NULL;
922 }
923 return (void *) entry;
924 }
925
926 STATIC void
S_hv_magic_check(HV * hv,bool * needs_copy,bool * needs_store)927 S_hv_magic_check(HV *hv, bool *needs_copy, bool *needs_store)
928 {
929 const MAGIC *mg = SvMAGIC(hv);
930
931 PERL_ARGS_ASSERT_HV_MAGIC_CHECK;
932
933 *needs_copy = FALSE;
934 *needs_store = TRUE;
935 while (mg) {
936 if (isUPPER(mg->mg_type)) {
937 *needs_copy = TRUE;
938 if (mg->mg_type == PERL_MAGIC_tied) {
939 *needs_store = FALSE;
940 return; /* We've set all there is to set. */
941 }
942 }
943 mg = mg->mg_moremagic;
944 }
945 }
946
947 /*
948 =for apidoc hv_scalar
949
950 Evaluates the hash in scalar context and returns the result.
951
952 When the hash is tied dispatches through to the SCALAR method,
953 otherwise returns a mortal SV containing the number of keys
954 in the hash.
955
956 Note, prior to 5.25 this function returned what is now
957 returned by the hv_bucket_ratio() function.
958
959 =cut
960 */
961
962 SV *
Perl_hv_scalar(pTHX_ HV * hv)963 Perl_hv_scalar(pTHX_ HV *hv)
964 {
965 SV *sv;
966
967 PERL_ARGS_ASSERT_HV_SCALAR;
968
969 if (SvRMAGICAL(hv)) {
970 MAGIC * const mg = mg_find((const SV *)hv, PERL_MAGIC_tied);
971 if (mg)
972 return magic_scalarpack(hv, mg);
973 }
974
975 sv = sv_newmortal();
976 sv_setuv(sv, HvUSEDKEYS(hv));
977
978 return sv;
979 }
980
981
982 /*
983 hv_pushkv(): push all the keys and/or values of a hash onto the stack.
984 The rough Perl equivalents:
985 () = %hash;
986 () = keys %hash;
987 () = values %hash;
988
989 Resets the hash's iterator.
990
991 flags : 1 = push keys
992 2 = push values
993 1|2 = push keys and values
994 XXX use symbolic flag constants at some point?
995 I might unroll the non-tied hv_iternext() in here at some point - DAPM
996 */
997
998 void
Perl_hv_pushkv(pTHX_ HV * hv,U32 flags)999 Perl_hv_pushkv(pTHX_ HV *hv, U32 flags)
1000 {
1001 HE *entry;
1002 bool tied = SvRMAGICAL(hv) && (mg_find(MUTABLE_SV(hv), PERL_MAGIC_tied)
1003 #ifdef DYNAMIC_ENV_FETCH /* might not know number of keys yet */
1004 || mg_find(MUTABLE_SV(hv), PERL_MAGIC_env)
1005 #endif
1006 );
1007 dSP;
1008
1009 PERL_ARGS_ASSERT_HV_PUSHKV;
1010 assert(flags); /* must be pushing at least one of keys and values */
1011
1012 (void)hv_iterinit(hv);
1013
1014 if (tied) {
1015 SSize_t ext = (flags == 3) ? 2 : 1;
1016 while ((entry = hv_iternext(hv))) {
1017 EXTEND(SP, ext);
1018 if (flags & 1)
1019 PUSHs(hv_iterkeysv(entry));
1020 if (flags & 2)
1021 PUSHs(hv_iterval(hv, entry));
1022 }
1023 }
1024 else {
1025 Size_t nkeys = HvUSEDKEYS(hv);
1026 SSize_t ext;
1027
1028 if (!nkeys)
1029 return;
1030
1031 /* 2*nkeys() should never be big enough to truncate or wrap */
1032 assert(nkeys <= (SSize_t_MAX >> 1));
1033 ext = nkeys * ((flags == 3) ? 2 : 1);
1034
1035 EXTEND_MORTAL(nkeys);
1036 EXTEND(SP, ext);
1037
1038 while ((entry = hv_iternext(hv))) {
1039 if (flags & 1) {
1040 SV *keysv = newSVhek(HeKEY_hek(entry));
1041 SvTEMP_on(keysv);
1042 PL_tmps_stack[++PL_tmps_ix] = keysv;
1043 PUSHs(keysv);
1044 }
1045 if (flags & 2)
1046 PUSHs(HeVAL(entry));
1047 }
1048 }
1049
1050 PUTBACK;
1051 }
1052
1053
1054 /*
1055 =for apidoc hv_bucket_ratio
1056
1057 If the hash is tied dispatches through to the SCALAR tied method,
1058 otherwise if the hash contains no keys returns 0, otherwise returns
1059 a mortal sv containing a string specifying the number of used buckets,
1060 followed by a slash, followed by the number of available buckets.
1061
1062 This function is expensive, it must scan all of the buckets
1063 to determine which are used, and the count is NOT cached.
1064 In a large hash this could be a lot of buckets.
1065
1066 =cut
1067 */
1068
1069 SV *
Perl_hv_bucket_ratio(pTHX_ HV * hv)1070 Perl_hv_bucket_ratio(pTHX_ HV *hv)
1071 {
1072 SV *sv;
1073
1074 PERL_ARGS_ASSERT_HV_BUCKET_RATIO;
1075
1076 if (SvRMAGICAL(hv)) {
1077 MAGIC * const mg = mg_find((const SV *)hv, PERL_MAGIC_tied);
1078 if (mg)
1079 return magic_scalarpack(hv, mg);
1080 }
1081
1082 if (HvUSEDKEYS((HV *)hv)) {
1083 sv = sv_newmortal();
1084 Perl_sv_setpvf(aTHX_ sv, "%ld/%ld",
1085 (long)HvFILL(hv), (long)HvMAX(hv) + 1);
1086 }
1087 else
1088 sv = &PL_sv_zero;
1089
1090 return sv;
1091 }
1092
1093 /*
1094 =for apidoc hv_delete
1095
1096 Deletes a key/value pair in the hash. The value's SV is removed from
1097 the hash, made mortal, and returned to the caller. The absolute
1098 value of C<klen> is the length of the key. If C<klen> is negative the
1099 key is assumed to be in UTF-8-encoded Unicode. The C<flags> value
1100 will normally be zero; if set to C<G_DISCARD> then C<NULL> will be returned.
1101 C<NULL> will also be returned if the key is not found.
1102
1103 =for apidoc hv_delete_ent
1104
1105 Deletes a key/value pair in the hash. The value SV is removed from the hash,
1106 made mortal, and returned to the caller. The C<flags> value will normally be
1107 zero; if set to C<G_DISCARD> then C<NULL> will be returned. C<NULL> will also
1108 be returned if the key is not found. C<hash> can be a valid precomputed hash
1109 value, or 0 to ask for it to be computed.
1110
1111 =cut
1112 */
1113
1114 STATIC SV *
S_hv_delete_common(pTHX_ HV * hv,SV * keysv,const char * key,STRLEN klen,int k_flags,I32 d_flags,U32 hash)1115 S_hv_delete_common(pTHX_ HV *hv, SV *keysv, const char *key, STRLEN klen,
1116 int k_flags, I32 d_flags, U32 hash)
1117 {
1118 XPVHV* xhv;
1119 HE *entry;
1120 HE **oentry;
1121 HE **first_entry;
1122 bool is_utf8 = cBOOL(k_flags & HVhek_UTF8);
1123 int masked_flags;
1124 HEK *keysv_hek = NULL;
1125 U8 mro_changes = 0; /* 1 = isa; 2 = package moved */
1126 SV *sv;
1127 GV *gv = NULL;
1128 HV *stash = NULL;
1129
1130 if (SvMAGICAL(hv)) {
1131 bool needs_copy;
1132 bool needs_store;
1133 hv_magic_check (hv, &needs_copy, &needs_store);
1134
1135 if (needs_copy) {
1136 SV *sv;
1137 entry = (HE *) hv_common(hv, keysv, key, klen,
1138 k_flags & ~HVhek_FREEKEY,
1139 HV_FETCH_LVALUE|HV_DISABLE_UVAR_XKEY,
1140 NULL, hash);
1141 sv = entry ? HeVAL(entry) : NULL;
1142 if (sv) {
1143 if (SvMAGICAL(sv)) {
1144 mg_clear(sv);
1145 }
1146 if (!needs_store) {
1147 if (mg_find(sv, PERL_MAGIC_tiedelem)) {
1148 /* No longer an element */
1149 sv_unmagic(sv, PERL_MAGIC_tiedelem);
1150 return sv;
1151 }
1152 return NULL; /* element cannot be deleted */
1153 }
1154 #ifdef ENV_IS_CASELESS
1155 else if (mg_find((const SV *)hv, PERL_MAGIC_env)) {
1156 /* XXX This code isn't UTF8 clean. */
1157 keysv = newSVpvn_flags(key, klen, SVs_TEMP);
1158 if (k_flags & HVhek_FREEKEY) {
1159 Safefree(key);
1160 }
1161 key = strupr(SvPVX(keysv));
1162 is_utf8 = 0;
1163 k_flags = 0;
1164 hash = 0;
1165 }
1166 #endif
1167 }
1168 }
1169 }
1170 xhv = (XPVHV*)SvANY(hv);
1171 if (!HvTOTALKEYS(hv))
1172 return NULL;
1173
1174 if (is_utf8 && !(k_flags & HVhek_KEYCANONICAL)) {
1175 const char * const keysave = key;
1176 key = (char*)bytes_from_utf8((U8*)key, &klen, &is_utf8);
1177
1178 if (is_utf8)
1179 k_flags |= HVhek_UTF8;
1180 else
1181 k_flags &= ~HVhek_UTF8;
1182 if (key != keysave) {
1183 if (k_flags & HVhek_FREEKEY) {
1184 /* This shouldn't happen if our caller does what we expect,
1185 but strictly the API allows it. */
1186 Safefree(keysave);
1187 }
1188 k_flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
1189 }
1190 }
1191
1192 if (keysv && (SvIsCOW_shared_hash(keysv))) {
1193 if (HvSHAREKEYS(hv))
1194 keysv_hek = SvSHARED_HEK_FROM_PV(SvPVX_const(keysv));
1195 hash = SvSHARED_HASH(keysv);
1196 }
1197 else if (!hash)
1198 PERL_HASH(hash, key, klen);
1199
1200 masked_flags = (k_flags & HVhek_MASK);
1201
1202 first_entry = oentry = &(HvARRAY(hv))[hash & (I32) HvMAX(hv)];
1203 entry = *oentry;
1204
1205 if (!entry)
1206 goto not_found;
1207
1208 if (keysv_hek) {
1209 /* keysv is actually a HEK in disguise, so we can match just by
1210 * comparing the HEK pointers in the HE chain. There is a slight
1211 * caveat: on something like "\x80", which has both plain and utf8
1212 * representations, perl's hashes do encoding-insensitive lookups,
1213 * but preserve the encoding of the stored key. Thus a particular
1214 * key could map to two different HEKs in PL_strtab. We only
1215 * conclude 'not found' if all the flags are the same; otherwise
1216 * we fall back to a full search (this should only happen in rare
1217 * cases).
1218 */
1219 int keysv_flags = HEK_FLAGS(keysv_hek);
1220
1221 for (; entry; oentry = &HeNEXT(entry), entry = *oentry) {
1222 HEK *hek = HeKEY_hek(entry);
1223 if (hek == keysv_hek)
1224 goto found;
1225 if (HEK_FLAGS(hek) != keysv_flags)
1226 break; /* need to do full match */
1227 }
1228 if (!entry)
1229 goto not_found;
1230 /* failed on shortcut - do full search loop */
1231 oentry = first_entry;
1232 entry = *oentry;
1233 }
1234
1235 for (; entry; oentry = &HeNEXT(entry), entry = *oentry) {
1236 if (HeHASH(entry) != hash) /* strings can't be equal */
1237 continue;
1238 if (HeKLEN(entry) != (I32)klen)
1239 continue;
1240 if (memNE(HeKEY(entry),key,klen)) /* is this it? */
1241 continue;
1242 if ((HeKFLAGS(entry) ^ masked_flags) & HVhek_UTF8)
1243 continue;
1244
1245 found:
1246 if (hv == PL_strtab) {
1247 if (k_flags & HVhek_FREEKEY)
1248 Safefree(key);
1249 Perl_croak(aTHX_ S_strtab_error, "delete");
1250 }
1251
1252 sv = HeVAL(entry);
1253
1254 /* if placeholder is here, it's already been deleted.... */
1255 if (sv == &PL_sv_placeholder) {
1256 if (k_flags & HVhek_FREEKEY)
1257 Safefree(key);
1258 return NULL;
1259 }
1260 if (SvREADONLY(hv) && sv && SvREADONLY(sv)) {
1261 hv_notallowed(k_flags, key, klen,
1262 "Attempt to delete readonly key '%" SVf "' from"
1263 " a restricted hash");
1264 }
1265
1266 /*
1267 * If a restricted hash, rather than really deleting the entry, put
1268 * a placeholder there. This marks the key as being "approved", so
1269 * we can still access via not-really-existing key without raising
1270 * an error.
1271 */
1272 if (SvREADONLY(hv)) {
1273 /* We'll be saving this slot, so the number of allocated keys
1274 * doesn't go down, but the number placeholders goes up */
1275 HeVAL(entry) = &PL_sv_placeholder;
1276 HvPLACEHOLDERS(hv)++;
1277 }
1278 else {
1279 HeVAL(entry) = NULL;
1280 *oentry = HeNEXT(entry);
1281 if (SvOOK(hv) && entry == HvAUX(hv)->xhv_eiter /* HvEITER(hv) */) {
1282 HvLAZYDEL_on(hv);
1283 }
1284 else {
1285 if (SvOOK(hv) && HvLAZYDEL(hv) &&
1286 entry == HeNEXT(HvAUX(hv)->xhv_eiter))
1287 HeNEXT(HvAUX(hv)->xhv_eiter) = HeNEXT(entry);
1288 hv_free_ent(hv, entry);
1289 }
1290 xhv->xhv_keys--; /* HvTOTALKEYS(hv)-- */
1291 if (xhv->xhv_keys == 0)
1292 HvHASKFLAGS_off(hv);
1293 }
1294
1295 /* If this is a stash and the key ends with ::, then someone is
1296 * deleting a package.
1297 */
1298 if (sv && HvENAME_get(hv)) {
1299 gv = (GV *)sv;
1300 if ((
1301 (klen > 1 && key[klen-2] == ':' && key[klen-1] == ':')
1302 ||
1303 (klen == 1 && key[0] == ':')
1304 )
1305 && (klen != 6 || hv!=PL_defstash || memNE(key,"main::",6))
1306 && SvTYPE(gv) == SVt_PVGV && (stash = GvHV((GV *)gv))
1307 && HvENAME_get(stash)) {
1308 /* A previous version of this code checked that the
1309 * GV was still in the symbol table by fetching the
1310 * GV with its name. That is not necessary (and
1311 * sometimes incorrect), as HvENAME cannot be set
1312 * on hv if it is not in the symtab. */
1313 mro_changes = 2;
1314 /* Hang on to it for a bit. */
1315 SvREFCNT_inc_simple_void_NN(
1316 sv_2mortal((SV *)gv)
1317 );
1318 }
1319 else if (memEQs(key, klen, "ISA") && GvAV(gv)) {
1320 AV *isa = GvAV(gv);
1321 MAGIC *mg = mg_find((SV*)isa, PERL_MAGIC_isa);
1322
1323 mro_changes = 1;
1324 if (mg) {
1325 if (mg->mg_obj == (SV*)gv) {
1326 /* This is the only stash this ISA was used for.
1327 * The isaelem magic asserts if there's no
1328 * isa magic on the array, so explicitly
1329 * remove the magic on both the array and its
1330 * elements. @ISA shouldn't be /too/ large.
1331 */
1332 SV **svp, **end;
1333 strip_magic:
1334 svp = AvARRAY(isa);
1335 end = svp + (AvFILLp(isa)+1);
1336 while (svp < end) {
1337 if (*svp)
1338 mg_free_type(*svp, PERL_MAGIC_isaelem);
1339 ++svp;
1340 }
1341 mg_free_type((SV*)GvAV(gv), PERL_MAGIC_isa);
1342 }
1343 else {
1344 /* mg_obj is an array of stashes
1345 Note that the array doesn't keep a reference
1346 count on the stashes.
1347 */
1348 AV *av = (AV*)mg->mg_obj;
1349 SV **svp, **arrayp;
1350 SSize_t index;
1351 SSize_t items;
1352
1353 assert(SvTYPE(mg->mg_obj) == SVt_PVAV);
1354
1355 /* remove the stash from the magic array */
1356 arrayp = svp = AvARRAY(av);
1357 items = AvFILLp(av) + 1;
1358 if (items == 1) {
1359 assert(*arrayp == (SV *)gv);
1360 mg->mg_obj = NULL;
1361 /* avoid a double free on the last stash */
1362 AvFILLp(av) = -1;
1363 /* The magic isn't MGf_REFCOUNTED, so release
1364 * the array manually.
1365 */
1366 SvREFCNT_dec_NN(av);
1367 goto strip_magic;
1368 }
1369 else {
1370 while (items--) {
1371 if (*svp == (SV*)gv)
1372 break;
1373 ++svp;
1374 }
1375 index = svp - arrayp;
1376 assert(index >= 0 && index <= AvFILLp(av));
1377 if (index < AvFILLp(av)) {
1378 arrayp[index] = arrayp[AvFILLp(av)];
1379 }
1380 arrayp[AvFILLp(av)] = NULL;
1381 --AvFILLp(av);
1382 }
1383 }
1384 }
1385 }
1386 }
1387
1388 if (k_flags & HVhek_FREEKEY)
1389 Safefree(key);
1390
1391 if (sv) {
1392 /* deletion of method from stash */
1393 if (isGV(sv) && isGV_with_GP(sv) && GvCVu(sv)
1394 && HvENAME_get(hv))
1395 mro_method_changed_in(hv);
1396
1397 if (d_flags & G_DISCARD) {
1398 SvREFCNT_dec(sv);
1399 sv = NULL;
1400 }
1401 else {
1402 sv_2mortal(sv);
1403 }
1404 }
1405
1406 if (mro_changes == 1) mro_isa_changed_in(hv);
1407 else if (mro_changes == 2)
1408 mro_package_moved(NULL, stash, gv, 1);
1409
1410 return sv;
1411 }
1412
1413 not_found:
1414 if (SvREADONLY(hv)) {
1415 hv_notallowed(k_flags, key, klen,
1416 "Attempt to delete disallowed key '%" SVf "' from"
1417 " a restricted hash");
1418 }
1419
1420 if (k_flags & HVhek_FREEKEY)
1421 Safefree(key);
1422 return NULL;
1423 }
1424
1425
1426 STATIC void
S_hsplit(pTHX_ HV * hv,STRLEN const oldsize,STRLEN newsize)1427 S_hsplit(pTHX_ HV *hv, STRLEN const oldsize, STRLEN newsize)
1428 {
1429 STRLEN i = 0;
1430 char *a = (char*) HvARRAY(hv);
1431 HE **aep;
1432
1433 PERL_ARGS_ASSERT_HSPLIT;
1434 if (newsize > MAX_BUCKET_MAX+1)
1435 return;
1436
1437 PL_nomemok = TRUE;
1438 Renew(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize), char);
1439 PL_nomemok = FALSE;
1440 if (!a) {
1441 return;
1442 }
1443
1444 #ifdef PERL_HASH_RANDOMIZE_KEYS
1445 /* the idea of this is that we create a "random" value by hashing the address of
1446 * the array, we then use the low bit to decide if we insert at the top, or insert
1447 * second from top. After each such insert we rotate the hashed value. So we can
1448 * use the same hashed value over and over, and in normal build environments use
1449 * very few ops to do so. ROTL32() should produce a single machine operation. */
1450 if (PL_HASH_RAND_BITS_ENABLED) {
1451 if (PL_HASH_RAND_BITS_ENABLED == 1)
1452 PL_hash_rand_bits += ptr_hash((PTRV)a);
1453 PL_hash_rand_bits = ROTL_UV(PL_hash_rand_bits,1);
1454 }
1455 #endif
1456 HvARRAY(hv) = (HE**) a;
1457 HvMAX(hv) = newsize - 1;
1458 /* now we can safely clear the second half */
1459 Zero(&a[oldsize * sizeof(HE*)], (newsize-oldsize) * sizeof(HE*), char); /* zero 2nd half*/
1460
1461 if (!HvTOTALKEYS(hv)) /* skip rest if no entries */
1462 return;
1463
1464 newsize--;
1465 aep = (HE**)a;
1466 do {
1467 HE **oentry = aep + i;
1468 HE *entry = aep[i];
1469
1470 if (!entry) /* non-existent */
1471 continue;
1472 do {
1473 U32 j = (HeHASH(entry) & newsize);
1474 if (j != (U32)i) {
1475 *oentry = HeNEXT(entry);
1476 #ifdef PERL_HASH_RANDOMIZE_KEYS
1477 /* if the target cell is empty or PL_HASH_RAND_BITS_ENABLED is false
1478 * insert to top, otherwise rotate the bucket rand 1 bit,
1479 * and use the new low bit to decide if we insert at top,
1480 * or next from top. IOW, we only rotate on a collision.*/
1481 if (aep[j] && PL_HASH_RAND_BITS_ENABLED) {
1482 PL_hash_rand_bits+= ROTL32(HeHASH(entry), 17);
1483 PL_hash_rand_bits= ROTL_UV(PL_hash_rand_bits,1);
1484 if (PL_hash_rand_bits & 1) {
1485 HeNEXT(entry)= HeNEXT(aep[j]);
1486 HeNEXT(aep[j])= entry;
1487 } else {
1488 /* Note, this is structured in such a way as the optimizer
1489 * should eliminate the duplicated code here and below without
1490 * us needing to explicitly use a goto. */
1491 HeNEXT(entry) = aep[j];
1492 aep[j] = entry;
1493 }
1494 } else
1495 #endif
1496 {
1497 /* see comment above about duplicated code */
1498 HeNEXT(entry) = aep[j];
1499 aep[j] = entry;
1500 }
1501 }
1502 else {
1503 oentry = &HeNEXT(entry);
1504 }
1505 entry = *oentry;
1506 } while (entry);
1507 } while (i++ < oldsize);
1508 }
1509
1510 void
Perl_hv_ksplit(pTHX_ HV * hv,IV newmax)1511 Perl_hv_ksplit(pTHX_ HV *hv, IV newmax)
1512 {
1513 XPVHV* xhv = (XPVHV*)SvANY(hv);
1514 const I32 oldsize = (I32) xhv->xhv_max+1; /* HvMAX(hv)+1 */
1515 I32 newsize;
1516 I32 wantsize;
1517 I32 trysize;
1518 char *a;
1519
1520 PERL_ARGS_ASSERT_HV_KSPLIT;
1521
1522 wantsize = (I32) newmax; /* possible truncation here */
1523 if (wantsize != newmax)
1524 return;
1525
1526 wantsize= wantsize + (wantsize >> 1); /* wantsize *= 1.5 */
1527 if (wantsize < newmax) /* overflow detection */
1528 return;
1529
1530 newsize = oldsize;
1531 while (wantsize > newsize) {
1532 trysize = newsize << 1;
1533 if (trysize > newsize) {
1534 newsize = trysize;
1535 } else {
1536 /* we overflowed */
1537 return;
1538 }
1539 }
1540
1541 if (newsize <= oldsize)
1542 return; /* overflow detection */
1543
1544 a = (char *) HvARRAY(hv);
1545 if (a) {
1546 #ifdef PERL_HASH_RANDOMIZE_KEYS
1547 U32 was_ook = SvOOK(hv);
1548 #endif
1549 hsplit(hv, oldsize, newsize);
1550 #ifdef PERL_HASH_RANDOMIZE_KEYS
1551 if (was_ook && SvOOK(hv) && HvTOTALKEYS(hv)) {
1552 HvAUX(hv)->xhv_rand = (U32)PL_hash_rand_bits;
1553 }
1554 #endif
1555 } else {
1556 Newxz(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize), char);
1557 xhv->xhv_max = newsize - 1;
1558 HvARRAY(hv) = (HE **) a;
1559 }
1560 }
1561
1562 /* IMO this should also handle cases where hv_max is smaller than hv_keys
1563 * as tied hashes could play silly buggers and mess us around. We will
1564 * do the right thing during hv_store() afterwards, but still - Yves */
1565 #define HV_SET_MAX_ADJUSTED_FOR_KEYS(hv,hv_max,hv_keys) STMT_START {\
1566 /* Can we use fewer buckets? (hv_max is always 2^n-1) */ \
1567 if (hv_max < PERL_HASH_DEFAULT_HvMAX) { \
1568 hv_max = PERL_HASH_DEFAULT_HvMAX; \
1569 } else { \
1570 while (hv_max > PERL_HASH_DEFAULT_HvMAX && hv_max + 1 >= hv_keys * 2) \
1571 hv_max = hv_max / 2; \
1572 } \
1573 HvMAX(hv) = hv_max; \
1574 } STMT_END
1575
1576
1577 HV *
Perl_newHVhv(pTHX_ HV * ohv)1578 Perl_newHVhv(pTHX_ HV *ohv)
1579 {
1580 HV * const hv = newHV();
1581 STRLEN hv_max;
1582
1583 if (!ohv || (!HvTOTALKEYS(ohv) && !SvMAGICAL((const SV *)ohv)))
1584 return hv;
1585 hv_max = HvMAX(ohv);
1586
1587 if (!SvMAGICAL((const SV *)ohv)) {
1588 /* It's an ordinary hash, so copy it fast. AMS 20010804 */
1589 STRLEN i;
1590 const bool shared = !!HvSHAREKEYS(ohv);
1591 HE **ents, ** const oents = (HE **)HvARRAY(ohv);
1592 char *a;
1593 Newx(a, PERL_HV_ARRAY_ALLOC_BYTES(hv_max+1), char);
1594 ents = (HE**)a;
1595
1596 /* In each bucket... */
1597 for (i = 0; i <= hv_max; i++) {
1598 HE *prev = NULL;
1599 HE *oent = oents[i];
1600
1601 if (!oent) {
1602 ents[i] = NULL;
1603 continue;
1604 }
1605
1606 /* Copy the linked list of entries. */
1607 for (; oent; oent = HeNEXT(oent)) {
1608 const U32 hash = HeHASH(oent);
1609 const char * const key = HeKEY(oent);
1610 const STRLEN len = HeKLEN(oent);
1611 const int flags = HeKFLAGS(oent);
1612 HE * const ent = new_HE();
1613 SV *const val = HeVAL(oent);
1614
1615 HeVAL(ent) = SvIMMORTAL(val) ? val : newSVsv(val);
1616 HeKEY_hek(ent)
1617 = shared ? share_hek_flags(key, len, hash, flags)
1618 : save_hek_flags(key, len, hash, flags);
1619 if (prev)
1620 HeNEXT(prev) = ent;
1621 else
1622 ents[i] = ent;
1623 prev = ent;
1624 HeNEXT(ent) = NULL;
1625 }
1626 }
1627
1628 HvMAX(hv) = hv_max;
1629 HvTOTALKEYS(hv) = HvTOTALKEYS(ohv);
1630 HvARRAY(hv) = ents;
1631 } /* not magical */
1632 else {
1633 /* Iterate over ohv, copying keys and values one at a time. */
1634 HE *entry;
1635 const I32 riter = HvRITER_get(ohv);
1636 HE * const eiter = HvEITER_get(ohv);
1637 STRLEN hv_keys = HvTOTALKEYS(ohv);
1638
1639 HV_SET_MAX_ADJUSTED_FOR_KEYS(hv,hv_max,hv_keys);
1640
1641 hv_iterinit(ohv);
1642 while ((entry = hv_iternext_flags(ohv, 0))) {
1643 SV *val = hv_iterval(ohv,entry);
1644 SV * const keysv = HeSVKEY(entry);
1645 val = SvIMMORTAL(val) ? val : newSVsv(val);
1646 if (keysv)
1647 (void)hv_store_ent(hv, keysv, val, 0);
1648 else
1649 (void)hv_store_flags(hv, HeKEY(entry), HeKLEN(entry), val,
1650 HeHASH(entry), HeKFLAGS(entry));
1651 }
1652 HvRITER_set(ohv, riter);
1653 HvEITER_set(ohv, eiter);
1654 }
1655
1656 return hv;
1657 }
1658
1659 /*
1660 =for apidoc hv_copy_hints_hv
1661
1662 A specialised version of L</newHVhv> for copying C<%^H>. C<ohv> must be
1663 a pointer to a hash (which may have C<%^H> magic, but should be generally
1664 non-magical), or C<NULL> (interpreted as an empty hash). The content
1665 of C<ohv> is copied to a new hash, which has the C<%^H>-specific magic
1666 added to it. A pointer to the new hash is returned.
1667
1668 =cut
1669 */
1670
1671 HV *
Perl_hv_copy_hints_hv(pTHX_ HV * const ohv)1672 Perl_hv_copy_hints_hv(pTHX_ HV *const ohv)
1673 {
1674 HV * const hv = newHV();
1675
1676 if (ohv) {
1677 STRLEN hv_max = HvMAX(ohv);
1678 STRLEN hv_keys = HvTOTALKEYS(ohv);
1679 HE *entry;
1680 const I32 riter = HvRITER_get(ohv);
1681 HE * const eiter = HvEITER_get(ohv);
1682
1683 ENTER;
1684 SAVEFREESV(hv);
1685
1686 HV_SET_MAX_ADJUSTED_FOR_KEYS(hv,hv_max,hv_keys);
1687
1688 hv_iterinit(ohv);
1689 while ((entry = hv_iternext_flags(ohv, 0))) {
1690 SV *const sv = newSVsv(hv_iterval(ohv,entry));
1691 SV *heksv = HeSVKEY(entry);
1692 if (!heksv && sv) heksv = newSVhek(HeKEY_hek(entry));
1693 if (sv) sv_magic(sv, NULL, PERL_MAGIC_hintselem,
1694 (char *)heksv, HEf_SVKEY);
1695 if (heksv == HeSVKEY(entry))
1696 (void)hv_store_ent(hv, heksv, sv, 0);
1697 else {
1698 (void)hv_common(hv, heksv, HeKEY(entry), HeKLEN(entry),
1699 HeKFLAGS(entry), HV_FETCH_ISSTORE|HV_FETCH_JUST_SV, sv, HeHASH(entry));
1700 SvREFCNT_dec_NN(heksv);
1701 }
1702 }
1703 HvRITER_set(ohv, riter);
1704 HvEITER_set(ohv, eiter);
1705
1706 SvREFCNT_inc_simple_void_NN(hv);
1707 LEAVE;
1708 }
1709 hv_magic(hv, NULL, PERL_MAGIC_hints);
1710 return hv;
1711 }
1712 #undef HV_SET_MAX_ADJUSTED_FOR_KEYS
1713
1714 /* like hv_free_ent, but returns the SV rather than freeing it */
1715 STATIC SV*
S_hv_free_ent_ret(pTHX_ HV * hv,HE * entry)1716 S_hv_free_ent_ret(pTHX_ HV *hv, HE *entry)
1717 {
1718 SV *val;
1719
1720 PERL_ARGS_ASSERT_HV_FREE_ENT_RET;
1721
1722 val = HeVAL(entry);
1723 if (HeKLEN(entry) == HEf_SVKEY) {
1724 SvREFCNT_dec(HeKEY_sv(entry));
1725 Safefree(HeKEY_hek(entry));
1726 }
1727 else if (HvSHAREKEYS(hv))
1728 unshare_hek(HeKEY_hek(entry));
1729 else
1730 Safefree(HeKEY_hek(entry));
1731 del_HE(entry);
1732 return val;
1733 }
1734
1735
1736 void
Perl_hv_free_ent(pTHX_ HV * hv,HE * entry)1737 Perl_hv_free_ent(pTHX_ HV *hv, HE *entry)
1738 {
1739 SV *val;
1740
1741 PERL_ARGS_ASSERT_HV_FREE_ENT;
1742
1743 if (!entry)
1744 return;
1745 val = hv_free_ent_ret(hv, entry);
1746 SvREFCNT_dec(val);
1747 }
1748
1749
1750 void
Perl_hv_delayfree_ent(pTHX_ HV * hv,HE * entry)1751 Perl_hv_delayfree_ent(pTHX_ HV *hv, HE *entry)
1752 {
1753 PERL_ARGS_ASSERT_HV_DELAYFREE_ENT;
1754
1755 if (!entry)
1756 return;
1757 /* SvREFCNT_inc to counter the SvREFCNT_dec in hv_free_ent */
1758 sv_2mortal(SvREFCNT_inc(HeVAL(entry))); /* free between statements */
1759 if (HeKLEN(entry) == HEf_SVKEY) {
1760 sv_2mortal(SvREFCNT_inc(HeKEY_sv(entry)));
1761 }
1762 hv_free_ent(hv, entry);
1763 }
1764
1765 /*
1766 =for apidoc hv_clear
1767
1768 Frees all the elements of a hash, leaving it empty.
1769 The XS equivalent of C<%hash = ()>. See also L</hv_undef>.
1770
1771 See L</av_clear> for a note about the hash possibly being invalid on
1772 return.
1773
1774 =cut
1775 */
1776
1777 void
Perl_hv_clear(pTHX_ HV * hv)1778 Perl_hv_clear(pTHX_ HV *hv)
1779 {
1780 SSize_t orig_ix;
1781
1782 XPVHV* xhv;
1783 if (!hv)
1784 return;
1785
1786 DEBUG_A(Perl_hv_assert(aTHX_ hv));
1787
1788 xhv = (XPVHV*)SvANY(hv);
1789
1790 /* avoid hv being freed when calling destructors below */
1791 EXTEND_MORTAL(1);
1792 PL_tmps_stack[++PL_tmps_ix] = SvREFCNT_inc_simple_NN(hv);
1793 orig_ix = PL_tmps_ix;
1794 if (SvREADONLY(hv) && HvTOTALKEYS(hv)) {
1795 /* restricted hash: convert all keys to placeholders */
1796 STRLEN i;
1797 for (i = 0; i <= xhv->xhv_max; i++) {
1798 HE *entry = (HvARRAY(hv))[i];
1799 for (; entry; entry = HeNEXT(entry)) {
1800 /* not already placeholder */
1801 if (HeVAL(entry) != &PL_sv_placeholder) {
1802 if (HeVAL(entry)) {
1803 if (SvREADONLY(HeVAL(entry))) {
1804 SV* const keysv = hv_iterkeysv(entry);
1805 Perl_croak_nocontext(
1806 "Attempt to delete readonly key '%" SVf "' from a restricted hash",
1807 (void*)keysv);
1808 }
1809 SvREFCNT_dec_NN(HeVAL(entry));
1810 }
1811 HeVAL(entry) = &PL_sv_placeholder;
1812 HvPLACEHOLDERS(hv)++;
1813 }
1814 }
1815 }
1816 }
1817 else {
1818 hv_free_entries(hv);
1819 HvPLACEHOLDERS_set(hv, 0);
1820
1821 if (SvRMAGICAL(hv))
1822 mg_clear(MUTABLE_SV(hv));
1823
1824 HvHASKFLAGS_off(hv);
1825 }
1826 if (SvOOK(hv)) {
1827 if(HvENAME_get(hv))
1828 mro_isa_changed_in(hv);
1829 HvEITER_set(hv, NULL);
1830 }
1831 /* disarm hv's premature free guard */
1832 if (LIKELY(PL_tmps_ix == orig_ix))
1833 PL_tmps_ix--;
1834 else
1835 PL_tmps_stack[orig_ix] = &PL_sv_undef;
1836 SvREFCNT_dec_NN(hv);
1837 }
1838
1839 /*
1840 =for apidoc hv_clear_placeholders
1841
1842 Clears any placeholders from a hash. If a restricted hash has any of its keys
1843 marked as readonly and the key is subsequently deleted, the key is not actually
1844 deleted but is marked by assigning it a value of C<&PL_sv_placeholder>. This tags
1845 it so it will be ignored by future operations such as iterating over the hash,
1846 but will still allow the hash to have a value reassigned to the key at some
1847 future point. This function clears any such placeholder keys from the hash.
1848 See C<L<Hash::Util::lock_keys()|Hash::Util/lock_keys>> for an example of its
1849 use.
1850
1851 =cut
1852 */
1853
1854 void
Perl_hv_clear_placeholders(pTHX_ HV * hv)1855 Perl_hv_clear_placeholders(pTHX_ HV *hv)
1856 {
1857 const U32 items = (U32)HvPLACEHOLDERS_get(hv);
1858
1859 PERL_ARGS_ASSERT_HV_CLEAR_PLACEHOLDERS;
1860
1861 if (items)
1862 clear_placeholders(hv, items);
1863 }
1864
1865 static void
S_clear_placeholders(pTHX_ HV * hv,const U32 placeholders)1866 S_clear_placeholders(pTHX_ HV *hv, const U32 placeholders)
1867 {
1868 I32 i;
1869 U32 to_find = placeholders;
1870
1871 PERL_ARGS_ASSERT_CLEAR_PLACEHOLDERS;
1872
1873 assert(to_find);
1874
1875 i = HvMAX(hv);
1876 do {
1877 /* Loop down the linked list heads */
1878 HE **oentry = &(HvARRAY(hv))[i];
1879 HE *entry;
1880
1881 while ((entry = *oentry)) {
1882 if (HeVAL(entry) == &PL_sv_placeholder) {
1883 *oentry = HeNEXT(entry);
1884 if (entry == HvEITER_get(hv))
1885 HvLAZYDEL_on(hv);
1886 else {
1887 if (SvOOK(hv) && HvLAZYDEL(hv) &&
1888 entry == HeNEXT(HvAUX(hv)->xhv_eiter))
1889 HeNEXT(HvAUX(hv)->xhv_eiter) = HeNEXT(entry);
1890 hv_free_ent(hv, entry);
1891 }
1892
1893 if (--to_find == 0) {
1894 /* Finished. */
1895 HvTOTALKEYS(hv) -= (IV)placeholders;
1896 if (HvTOTALKEYS(hv) == 0)
1897 HvHASKFLAGS_off(hv);
1898 HvPLACEHOLDERS_set(hv, 0);
1899 return;
1900 }
1901 } else {
1902 oentry = &HeNEXT(entry);
1903 }
1904 }
1905 } while (--i >= 0);
1906 /* You can't get here, hence assertion should always fail. */
1907 assert (to_find == 0);
1908 NOT_REACHED; /* NOTREACHED */
1909 }
1910
1911 STATIC void
S_hv_free_entries(pTHX_ HV * hv)1912 S_hv_free_entries(pTHX_ HV *hv)
1913 {
1914 STRLEN index = 0;
1915 XPVHV * const xhv = (XPVHV*)SvANY(hv);
1916 SV *sv;
1917
1918 PERL_ARGS_ASSERT_HV_FREE_ENTRIES;
1919
1920 while ((sv = Perl_hfree_next_entry(aTHX_ hv, &index))||xhv->xhv_keys) {
1921 SvREFCNT_dec(sv);
1922 }
1923 }
1924
1925
1926 /* hfree_next_entry()
1927 * For use only by S_hv_free_entries() and sv_clear().
1928 * Delete the next available HE from hv and return the associated SV.
1929 * Returns null on empty hash. Nevertheless null is not a reliable
1930 * indicator that the hash is empty, as the deleted entry may have a
1931 * null value.
1932 * indexp is a pointer to the current index into HvARRAY. The index should
1933 * initially be set to 0. hfree_next_entry() may update it. */
1934
1935 SV*
Perl_hfree_next_entry(pTHX_ HV * hv,STRLEN * indexp)1936 Perl_hfree_next_entry(pTHX_ HV *hv, STRLEN *indexp)
1937 {
1938 struct xpvhv_aux *iter;
1939 HE *entry;
1940 HE ** array;
1941 #ifdef DEBUGGING
1942 STRLEN orig_index = *indexp;
1943 #endif
1944
1945 PERL_ARGS_ASSERT_HFREE_NEXT_ENTRY;
1946
1947 if (SvOOK(hv) && ((iter = HvAUX(hv)))) {
1948 if ((entry = iter->xhv_eiter)) {
1949 /* the iterator may get resurrected after each
1950 * destructor call, so check each time */
1951 if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */
1952 HvLAZYDEL_off(hv);
1953 hv_free_ent(hv, entry);
1954 /* warning: at this point HvARRAY may have been
1955 * re-allocated, HvMAX changed etc */
1956 }
1957 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1958 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1959 #ifdef PERL_HASH_RANDOMIZE_KEYS
1960 iter->xhv_last_rand = iter->xhv_rand;
1961 #endif
1962 }
1963 }
1964
1965 if (!((XPVHV*)SvANY(hv))->xhv_keys)
1966 return NULL;
1967
1968 array = HvARRAY(hv);
1969 assert(array);
1970 while ( ! ((entry = array[*indexp])) ) {
1971 if ((*indexp)++ >= HvMAX(hv))
1972 *indexp = 0;
1973 assert(*indexp != orig_index);
1974 }
1975 array[*indexp] = HeNEXT(entry);
1976 ((XPVHV*) SvANY(hv))->xhv_keys--;
1977
1978 if ( PL_phase != PERL_PHASE_DESTRUCT && HvENAME(hv)
1979 && HeVAL(entry) && isGV(HeVAL(entry))
1980 && GvHV(HeVAL(entry)) && HvENAME(GvHV(HeVAL(entry)))
1981 ) {
1982 STRLEN klen;
1983 const char * const key = HePV(entry,klen);
1984 if ((klen > 1 && key[klen-1]==':' && key[klen-2]==':')
1985 || (klen == 1 && key[0] == ':')) {
1986 mro_package_moved(
1987 NULL, GvHV(HeVAL(entry)),
1988 (GV *)HeVAL(entry), 0
1989 );
1990 }
1991 }
1992 return hv_free_ent_ret(hv, entry);
1993 }
1994
1995
1996 /*
1997 =for apidoc hv_undef
1998
1999 Undefines the hash. The XS equivalent of C<undef(%hash)>.
2000
2001 As well as freeing all the elements of the hash (like C<hv_clear()>), this
2002 also frees any auxiliary data and storage associated with the hash.
2003
2004 See L</av_clear> for a note about the hash possibly being invalid on
2005 return.
2006
2007 =cut
2008 */
2009
2010 void
Perl_hv_undef_flags(pTHX_ HV * hv,U32 flags)2011 Perl_hv_undef_flags(pTHX_ HV *hv, U32 flags)
2012 {
2013 XPVHV* xhv;
2014 bool save;
2015 SSize_t orig_ix = PL_tmps_ix; /* silence compiler warning about unitialized vars */
2016
2017 if (!hv)
2018 return;
2019 save = cBOOL(SvREFCNT(hv));
2020 DEBUG_A(Perl_hv_assert(aTHX_ hv));
2021 xhv = (XPVHV*)SvANY(hv);
2022
2023 /* The name must be deleted before the call to hv_free_entries so that
2024 CVs are anonymised properly. But the effective name must be pre-
2025 served until after that call (and only deleted afterwards if the
2026 call originated from sv_clear). For stashes with one name that is
2027 both the canonical name and the effective name, hv_name_set has to
2028 allocate an array for storing the effective name. We can skip that
2029 during global destruction, as it does not matter where the CVs point
2030 if they will be freed anyway. */
2031 /* note that the code following prior to hv_free_entries is duplicated
2032 * in sv_clear(), and changes here should be done there too */
2033 if (PL_phase != PERL_PHASE_DESTRUCT && HvNAME(hv)) {
2034 if (PL_stashcache) {
2035 DEBUG_o(Perl_deb(aTHX_ "hv_undef_flags clearing PL_stashcache for '%"
2036 HEKf "'\n", HEKfARG(HvNAME_HEK(hv))));
2037 (void)hv_deletehek(PL_stashcache, HvNAME_HEK(hv), G_DISCARD);
2038 }
2039 hv_name_set(hv, NULL, 0, 0);
2040 }
2041 if (save) {
2042 /* avoid hv being freed when calling destructors below */
2043 EXTEND_MORTAL(1);
2044 PL_tmps_stack[++PL_tmps_ix] = SvREFCNT_inc_simple_NN(hv);
2045 orig_ix = PL_tmps_ix;
2046 }
2047 hv_free_entries(hv);
2048 if (SvOOK(hv)) {
2049 struct mro_meta *meta;
2050 const char *name;
2051
2052 if (HvENAME_get(hv)) {
2053 if (PL_phase != PERL_PHASE_DESTRUCT)
2054 mro_isa_changed_in(hv);
2055 if (PL_stashcache) {
2056 DEBUG_o(Perl_deb(aTHX_ "hv_undef_flags clearing PL_stashcache for effective name '%"
2057 HEKf "'\n", HEKfARG(HvENAME_HEK(hv))));
2058 (void)hv_deletehek(PL_stashcache, HvENAME_HEK(hv), G_DISCARD);
2059 }
2060 }
2061
2062 /* If this call originated from sv_clear, then we must check for
2063 * effective names that need freeing, as well as the usual name. */
2064 name = HvNAME(hv);
2065 if (flags & HV_NAME_SETALL ? !!HvAUX(hv)->xhv_name_u.xhvnameu_name : !!name) {
2066 if (name && PL_stashcache) {
2067 DEBUG_o(Perl_deb(aTHX_ "hv_undef_flags clearing PL_stashcache for name '%"
2068 HEKf "'\n", HEKfARG(HvNAME_HEK(hv))));
2069 (void)hv_deletehek(PL_stashcache, HvNAME_HEK(hv), G_DISCARD);
2070 }
2071 hv_name_set(hv, NULL, 0, flags);
2072 }
2073 if((meta = HvAUX(hv)->xhv_mro_meta)) {
2074 if (meta->mro_linear_all) {
2075 SvREFCNT_dec_NN(meta->mro_linear_all);
2076 /* mro_linear_current is just acting as a shortcut pointer,
2077 hence the else. */
2078 }
2079 else
2080 /* Only the current MRO is stored, so this owns the data.
2081 */
2082 SvREFCNT_dec(meta->mro_linear_current);
2083 SvREFCNT_dec(meta->mro_nextmethod);
2084 SvREFCNT_dec(meta->isa);
2085 SvREFCNT_dec(meta->super);
2086 Safefree(meta);
2087 HvAUX(hv)->xhv_mro_meta = NULL;
2088 }
2089 if (!HvAUX(hv)->xhv_name_u.xhvnameu_name && ! HvAUX(hv)->xhv_backreferences)
2090 SvFLAGS(hv) &= ~SVf_OOK;
2091 }
2092 if (!SvOOK(hv)) {
2093 Safefree(HvARRAY(hv));
2094 xhv->xhv_max = PERL_HASH_DEFAULT_HvMAX; /* HvMAX(hv) = 7 (it's a normal hash) */
2095 HvARRAY(hv) = 0;
2096 }
2097 /* if we're freeing the HV, the SvMAGIC field has been reused for
2098 * other purposes, and so there can't be any placeholder magic */
2099 if (SvREFCNT(hv))
2100 HvPLACEHOLDERS_set(hv, 0);
2101
2102 if (SvRMAGICAL(hv))
2103 mg_clear(MUTABLE_SV(hv));
2104
2105 if (save) {
2106 /* disarm hv's premature free guard */
2107 if (LIKELY(PL_tmps_ix == orig_ix))
2108 PL_tmps_ix--;
2109 else
2110 PL_tmps_stack[orig_ix] = &PL_sv_undef;
2111 SvREFCNT_dec_NN(hv);
2112 }
2113 }
2114
2115 /*
2116 =for apidoc hv_fill
2117
2118 Returns the number of hash buckets that happen to be in use.
2119
2120 This function is wrapped by the macro C<HvFILL>.
2121
2122 As of perl 5.25 this function is used only for debugging
2123 purposes, and the number of used hash buckets is not
2124 in any way cached, thus this function can be costly
2125 to execute as it must iterate over all the buckets in the
2126 hash.
2127
2128 =cut
2129 */
2130
2131 STRLEN
Perl_hv_fill(pTHX_ HV * const hv)2132 Perl_hv_fill(pTHX_ HV *const hv)
2133 {
2134 STRLEN count = 0;
2135 HE **ents = HvARRAY(hv);
2136
2137 PERL_UNUSED_CONTEXT;
2138 PERL_ARGS_ASSERT_HV_FILL;
2139
2140 /* No keys implies no buckets used.
2141 One key can only possibly mean one bucket used. */
2142 if (HvTOTALKEYS(hv) < 2)
2143 return HvTOTALKEYS(hv);
2144
2145 if (ents) {
2146 /* I wonder why we count down here...
2147 * Is it some micro-optimisation?
2148 * I would have thought counting up was better.
2149 * - Yves
2150 */
2151 HE *const *const last = ents + HvMAX(hv);
2152 count = last + 1 - ents;
2153
2154 do {
2155 if (!*ents)
2156 --count;
2157 } while (++ents <= last);
2158 }
2159 return count;
2160 }
2161
2162 /* hash a pointer to a U32 - Used in the hash traversal randomization
2163 * and bucket order randomization code
2164 *
2165 * this code was derived from Sereal, which was derived from autobox.
2166 */
2167
S_ptr_hash(PTRV u)2168 PERL_STATIC_INLINE U32 S_ptr_hash(PTRV u) {
2169 #if PTRSIZE == 8
2170 /*
2171 * This is one of Thomas Wang's hash functions for 64-bit integers from:
2172 * http://www.concentric.net/~Ttwang/tech/inthash.htm
2173 */
2174 u = (~u) + (u << 18);
2175 u = u ^ (u >> 31);
2176 u = u * 21;
2177 u = u ^ (u >> 11);
2178 u = u + (u << 6);
2179 u = u ^ (u >> 22);
2180 #else
2181 /*
2182 * This is one of Bob Jenkins' hash functions for 32-bit integers
2183 * from: http://burtleburtle.net/bob/hash/integer.html
2184 */
2185 u = (u + 0x7ed55d16) + (u << 12);
2186 u = (u ^ 0xc761c23c) ^ (u >> 19);
2187 u = (u + 0x165667b1) + (u << 5);
2188 u = (u + 0xd3a2646c) ^ (u << 9);
2189 u = (u + 0xfd7046c5) + (u << 3);
2190 u = (u ^ 0xb55a4f09) ^ (u >> 16);
2191 #endif
2192 return (U32)u;
2193 }
2194
2195 static struct xpvhv_aux*
S_hv_auxinit(pTHX_ HV * hv)2196 S_hv_auxinit(pTHX_ HV *hv) {
2197 struct xpvhv_aux *iter;
2198 char *array;
2199
2200 PERL_ARGS_ASSERT_HV_AUXINIT;
2201
2202 if (!SvOOK(hv)) {
2203 if (!HvARRAY(hv)) {
2204 Newxz(array, PERL_HV_ARRAY_ALLOC_BYTES(HvMAX(hv) + 1), char);
2205 } else {
2206 array = (char *) HvARRAY(hv);
2207 Renew(array, PERL_HV_ARRAY_ALLOC_BYTES(HvMAX(hv) + 1), char);
2208 }
2209 HvARRAY(hv) = (HE**)array;
2210 iter = Perl_hv_auxalloc(aTHX_ hv);
2211 #ifdef PERL_HASH_RANDOMIZE_KEYS
2212 if (PL_HASH_RAND_BITS_ENABLED) {
2213 /* mix in some new state to PL_hash_rand_bits to "randomize" the traversal order*/
2214 if (PL_HASH_RAND_BITS_ENABLED == 1)
2215 PL_hash_rand_bits += ptr_hash((PTRV)array);
2216 PL_hash_rand_bits = ROTL_UV(PL_hash_rand_bits,1);
2217 }
2218 iter->xhv_rand = (U32)PL_hash_rand_bits;
2219 #endif
2220 } else {
2221 iter = HvAUX(hv);
2222 }
2223
2224 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
2225 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
2226 #ifdef PERL_HASH_RANDOMIZE_KEYS
2227 iter->xhv_last_rand = iter->xhv_rand;
2228 #endif
2229 iter->xhv_name_u.xhvnameu_name = 0;
2230 iter->xhv_name_count = 0;
2231 iter->xhv_backreferences = 0;
2232 iter->xhv_mro_meta = NULL;
2233 iter->xhv_aux_flags = 0;
2234 return iter;
2235 }
2236
2237 /*
2238 =for apidoc hv_iterinit
2239
2240 Prepares a starting point to traverse a hash table. Returns the number of
2241 keys in the hash, including placeholders (i.e. the same as C<HvTOTALKEYS(hv)>).
2242 The return value is currently only meaningful for hashes without tie magic.
2243
2244 NOTE: Before version 5.004_65, C<hv_iterinit> used to return the number of
2245 hash buckets that happen to be in use. If you still need that esoteric
2246 value, you can get it through the macro C<HvFILL(hv)>.
2247
2248
2249 =cut
2250 */
2251
2252 I32
Perl_hv_iterinit(pTHX_ HV * hv)2253 Perl_hv_iterinit(pTHX_ HV *hv)
2254 {
2255 PERL_ARGS_ASSERT_HV_ITERINIT;
2256
2257 if (SvOOK(hv)) {
2258 struct xpvhv_aux * iter = HvAUX(hv);
2259 HE * const entry = iter->xhv_eiter; /* HvEITER(hv) */
2260 if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */
2261 HvLAZYDEL_off(hv);
2262 hv_free_ent(hv, entry);
2263 }
2264 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
2265 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
2266 #ifdef PERL_HASH_RANDOMIZE_KEYS
2267 iter->xhv_last_rand = iter->xhv_rand;
2268 #endif
2269 } else {
2270 hv_auxinit(hv);
2271 }
2272
2273 /* note this includes placeholders! */
2274 return HvTOTALKEYS(hv);
2275 }
2276
2277 I32 *
Perl_hv_riter_p(pTHX_ HV * hv)2278 Perl_hv_riter_p(pTHX_ HV *hv) {
2279 struct xpvhv_aux *iter;
2280
2281 PERL_ARGS_ASSERT_HV_RITER_P;
2282
2283 iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
2284 return &(iter->xhv_riter);
2285 }
2286
2287 HE **
Perl_hv_eiter_p(pTHX_ HV * hv)2288 Perl_hv_eiter_p(pTHX_ HV *hv) {
2289 struct xpvhv_aux *iter;
2290
2291 PERL_ARGS_ASSERT_HV_EITER_P;
2292
2293 iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
2294 return &(iter->xhv_eiter);
2295 }
2296
2297 void
Perl_hv_riter_set(pTHX_ HV * hv,I32 riter)2298 Perl_hv_riter_set(pTHX_ HV *hv, I32 riter) {
2299 struct xpvhv_aux *iter;
2300
2301 PERL_ARGS_ASSERT_HV_RITER_SET;
2302
2303 if (SvOOK(hv)) {
2304 iter = HvAUX(hv);
2305 } else {
2306 if (riter == -1)
2307 return;
2308
2309 iter = hv_auxinit(hv);
2310 }
2311 iter->xhv_riter = riter;
2312 }
2313
2314 void
Perl_hv_rand_set(pTHX_ HV * hv,U32 new_xhv_rand)2315 Perl_hv_rand_set(pTHX_ HV *hv, U32 new_xhv_rand) {
2316 struct xpvhv_aux *iter;
2317
2318 PERL_ARGS_ASSERT_HV_RAND_SET;
2319
2320 #ifdef PERL_HASH_RANDOMIZE_KEYS
2321 if (SvOOK(hv)) {
2322 iter = HvAUX(hv);
2323 } else {
2324 iter = hv_auxinit(hv);
2325 }
2326 iter->xhv_rand = new_xhv_rand;
2327 #else
2328 Perl_croak(aTHX_ "This Perl has not been built with support for randomized hash key traversal but something called Perl_hv_rand_set().");
2329 #endif
2330 }
2331
2332 void
Perl_hv_eiter_set(pTHX_ HV * hv,HE * eiter)2333 Perl_hv_eiter_set(pTHX_ HV *hv, HE *eiter) {
2334 struct xpvhv_aux *iter;
2335
2336 PERL_ARGS_ASSERT_HV_EITER_SET;
2337
2338 if (SvOOK(hv)) {
2339 iter = HvAUX(hv);
2340 } else {
2341 /* 0 is the default so don't go malloc()ing a new structure just to
2342 hold 0. */
2343 if (!eiter)
2344 return;
2345
2346 iter = hv_auxinit(hv);
2347 }
2348 iter->xhv_eiter = eiter;
2349 }
2350
2351 void
Perl_hv_name_set(pTHX_ HV * hv,const char * name,U32 len,U32 flags)2352 Perl_hv_name_set(pTHX_ HV *hv, const char *name, U32 len, U32 flags)
2353 {
2354 struct xpvhv_aux *iter;
2355 U32 hash;
2356 HEK **spot;
2357
2358 PERL_ARGS_ASSERT_HV_NAME_SET;
2359
2360 if (len > I32_MAX)
2361 Perl_croak(aTHX_ "panic: hv name too long (%" UVuf ")", (UV) len);
2362
2363 if (SvOOK(hv)) {
2364 iter = HvAUX(hv);
2365 if (iter->xhv_name_u.xhvnameu_name) {
2366 if(iter->xhv_name_count) {
2367 if(flags & HV_NAME_SETALL) {
2368 HEK ** const this_name = HvAUX(hv)->xhv_name_u.xhvnameu_names;
2369 HEK **hekp = this_name + (
2370 iter->xhv_name_count < 0
2371 ? -iter->xhv_name_count
2372 : iter->xhv_name_count
2373 );
2374 while(hekp-- > this_name+1)
2375 unshare_hek_or_pvn(*hekp, 0, 0, 0);
2376 /* The first elem may be null. */
2377 if(*this_name) unshare_hek_or_pvn(*this_name, 0, 0, 0);
2378 Safefree(this_name);
2379 spot = &iter->xhv_name_u.xhvnameu_name;
2380 iter->xhv_name_count = 0;
2381 }
2382 else {
2383 if(iter->xhv_name_count > 0) {
2384 /* shift some things over */
2385 Renew(
2386 iter->xhv_name_u.xhvnameu_names, iter->xhv_name_count + 1, HEK *
2387 );
2388 spot = iter->xhv_name_u.xhvnameu_names;
2389 spot[iter->xhv_name_count] = spot[1];
2390 spot[1] = spot[0];
2391 iter->xhv_name_count = -(iter->xhv_name_count + 1);
2392 }
2393 else if(*(spot = iter->xhv_name_u.xhvnameu_names)) {
2394 unshare_hek_or_pvn(*spot, 0, 0, 0);
2395 }
2396 }
2397 }
2398 else if (flags & HV_NAME_SETALL) {
2399 unshare_hek_or_pvn(iter->xhv_name_u.xhvnameu_name, 0, 0, 0);
2400 spot = &iter->xhv_name_u.xhvnameu_name;
2401 }
2402 else {
2403 HEK * const existing_name = iter->xhv_name_u.xhvnameu_name;
2404 Newx(iter->xhv_name_u.xhvnameu_names, 2, HEK *);
2405 iter->xhv_name_count = -2;
2406 spot = iter->xhv_name_u.xhvnameu_names;
2407 spot[1] = existing_name;
2408 }
2409 }
2410 else { spot = &iter->xhv_name_u.xhvnameu_name; iter->xhv_name_count = 0; }
2411 } else {
2412 if (name == 0)
2413 return;
2414
2415 iter = hv_auxinit(hv);
2416 spot = &iter->xhv_name_u.xhvnameu_name;
2417 }
2418 PERL_HASH(hash, name, len);
2419 *spot = name ? share_hek(name, flags & SVf_UTF8 ? -(I32)len : (I32)len, hash) : NULL;
2420 }
2421
2422 /*
2423 This is basically sv_eq_flags() in sv.c, but we avoid the magic
2424 and bytes checking.
2425 */
2426
2427 STATIC I32
hek_eq_pvn_flags(pTHX_ const HEK * hek,const char * pv,const I32 pvlen,const U32 flags)2428 hek_eq_pvn_flags(pTHX_ const HEK *hek, const char* pv, const I32 pvlen, const U32 flags) {
2429 if ( (HEK_UTF8(hek) ? 1 : 0) != (flags & SVf_UTF8 ? 1 : 0) ) {
2430 if (flags & SVf_UTF8)
2431 return (bytes_cmp_utf8(
2432 (const U8*)HEK_KEY(hek), HEK_LEN(hek),
2433 (const U8*)pv, pvlen) == 0);
2434 else
2435 return (bytes_cmp_utf8(
2436 (const U8*)pv, pvlen,
2437 (const U8*)HEK_KEY(hek), HEK_LEN(hek)) == 0);
2438 }
2439 else
2440 return HEK_LEN(hek) == pvlen && ((HEK_KEY(hek) == pv)
2441 || memEQ(HEK_KEY(hek), pv, pvlen));
2442 }
2443
2444 /*
2445 =for apidoc hv_ename_add
2446
2447 Adds a name to a stash's internal list of effective names. See
2448 C<L</hv_ename_delete>>.
2449
2450 This is called when a stash is assigned to a new location in the symbol
2451 table.
2452
2453 =cut
2454 */
2455
2456 void
Perl_hv_ename_add(pTHX_ HV * hv,const char * name,U32 len,U32 flags)2457 Perl_hv_ename_add(pTHX_ HV *hv, const char *name, U32 len, U32 flags)
2458 {
2459 struct xpvhv_aux *aux = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
2460 U32 hash;
2461
2462 PERL_ARGS_ASSERT_HV_ENAME_ADD;
2463
2464 if (len > I32_MAX)
2465 Perl_croak(aTHX_ "panic: hv name too long (%" UVuf ")", (UV) len);
2466
2467 PERL_HASH(hash, name, len);
2468
2469 if (aux->xhv_name_count) {
2470 I32 count = aux->xhv_name_count;
2471 HEK ** const xhv_name = aux->xhv_name_u.xhvnameu_names + (count<0);
2472 HEK **hekp = xhv_name + (count < 0 ? -count - 1 : count);
2473 while (hekp-- > xhv_name)
2474 {
2475 assert(*hekp);
2476 if (
2477 (HEK_UTF8(*hekp) || (flags & SVf_UTF8))
2478 ? hek_eq_pvn_flags(aTHX_ *hekp, name, (I32)len, flags)
2479 : (HEK_LEN(*hekp) == (I32)len && memEQ(HEK_KEY(*hekp), name, len))
2480 ) {
2481 if (hekp == xhv_name && count < 0)
2482 aux->xhv_name_count = -count;
2483 return;
2484 }
2485 }
2486 if (count < 0) aux->xhv_name_count--, count = -count;
2487 else aux->xhv_name_count++;
2488 Renew(aux->xhv_name_u.xhvnameu_names, count + 1, HEK *);
2489 (aux->xhv_name_u.xhvnameu_names)[count] = share_hek(name, (flags & SVf_UTF8 ? -(I32)len : (I32)len), hash);
2490 }
2491 else {
2492 HEK *existing_name = aux->xhv_name_u.xhvnameu_name;
2493 if (
2494 existing_name && (
2495 (HEK_UTF8(existing_name) || (flags & SVf_UTF8))
2496 ? hek_eq_pvn_flags(aTHX_ existing_name, name, (I32)len, flags)
2497 : (HEK_LEN(existing_name) == (I32)len && memEQ(HEK_KEY(existing_name), name, len))
2498 )
2499 ) return;
2500 Newx(aux->xhv_name_u.xhvnameu_names, 2, HEK *);
2501 aux->xhv_name_count = existing_name ? 2 : -2;
2502 *aux->xhv_name_u.xhvnameu_names = existing_name;
2503 (aux->xhv_name_u.xhvnameu_names)[1] = share_hek(name, (flags & SVf_UTF8 ? -(I32)len : (I32)len), hash);
2504 }
2505 }
2506
2507 /*
2508 =for apidoc hv_ename_delete
2509
2510 Removes a name from a stash's internal list of effective names. If this is
2511 the name returned by C<HvENAME>, then another name in the list will take
2512 its place (C<HvENAME> will use it).
2513
2514 This is called when a stash is deleted from the symbol table.
2515
2516 =cut
2517 */
2518
2519 void
Perl_hv_ename_delete(pTHX_ HV * hv,const char * name,U32 len,U32 flags)2520 Perl_hv_ename_delete(pTHX_ HV *hv, const char *name, U32 len, U32 flags)
2521 {
2522 struct xpvhv_aux *aux;
2523
2524 PERL_ARGS_ASSERT_HV_ENAME_DELETE;
2525
2526 if (len > I32_MAX)
2527 Perl_croak(aTHX_ "panic: hv name too long (%" UVuf ")", (UV) len);
2528
2529 if (!SvOOK(hv)) return;
2530
2531 aux = HvAUX(hv);
2532 if (!aux->xhv_name_u.xhvnameu_name) return;
2533
2534 if (aux->xhv_name_count) {
2535 HEK ** const namep = aux->xhv_name_u.xhvnameu_names;
2536 I32 const count = aux->xhv_name_count;
2537 HEK **victim = namep + (count < 0 ? -count : count);
2538 while (victim-- > namep + 1)
2539 if (
2540 (HEK_UTF8(*victim) || (flags & SVf_UTF8))
2541 ? hek_eq_pvn_flags(aTHX_ *victim, name, (I32)len, flags)
2542 : (HEK_LEN(*victim) == (I32)len && memEQ(HEK_KEY(*victim), name, len))
2543 ) {
2544 unshare_hek_or_pvn(*victim, 0, 0, 0);
2545 if (count < 0) ++aux->xhv_name_count;
2546 else --aux->xhv_name_count;
2547 if (
2548 (aux->xhv_name_count == 1 || aux->xhv_name_count == -1)
2549 && !*namep
2550 ) { /* if there are none left */
2551 Safefree(namep);
2552 aux->xhv_name_u.xhvnameu_names = NULL;
2553 aux->xhv_name_count = 0;
2554 }
2555 else {
2556 /* Move the last one back to fill the empty slot. It
2557 does not matter what order they are in. */
2558 *victim = *(namep + (count < 0 ? -count : count) - 1);
2559 }
2560 return;
2561 }
2562 if (
2563 count > 0 && ((HEK_UTF8(*namep) || (flags & SVf_UTF8))
2564 ? hek_eq_pvn_flags(aTHX_ *namep, name, (I32)len, flags)
2565 : (HEK_LEN(*namep) == (I32)len && memEQ(HEK_KEY(*namep), name, len))
2566 )
2567 ) {
2568 aux->xhv_name_count = -count;
2569 }
2570 }
2571 else if(
2572 (HEK_UTF8(aux->xhv_name_u.xhvnameu_name) || (flags & SVf_UTF8))
2573 ? hek_eq_pvn_flags(aTHX_ aux->xhv_name_u.xhvnameu_name, name, (I32)len, flags)
2574 : (HEK_LEN(aux->xhv_name_u.xhvnameu_name) == (I32)len &&
2575 memEQ(HEK_KEY(aux->xhv_name_u.xhvnameu_name), name, len))
2576 ) {
2577 HEK * const namehek = aux->xhv_name_u.xhvnameu_name;
2578 Newx(aux->xhv_name_u.xhvnameu_names, 1, HEK *);
2579 *aux->xhv_name_u.xhvnameu_names = namehek;
2580 aux->xhv_name_count = -1;
2581 }
2582 }
2583
2584 AV **
Perl_hv_backreferences_p(pTHX_ HV * hv)2585 Perl_hv_backreferences_p(pTHX_ HV *hv) {
2586 PERL_ARGS_ASSERT_HV_BACKREFERENCES_P;
2587 /* See also Perl_sv_get_backrefs in sv.c where this logic is unrolled */
2588 {
2589 struct xpvhv_aux * const iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
2590 return &(iter->xhv_backreferences);
2591 }
2592 }
2593
2594 void
Perl_hv_kill_backrefs(pTHX_ HV * hv)2595 Perl_hv_kill_backrefs(pTHX_ HV *hv) {
2596 AV *av;
2597
2598 PERL_ARGS_ASSERT_HV_KILL_BACKREFS;
2599
2600 if (!SvOOK(hv))
2601 return;
2602
2603 av = HvAUX(hv)->xhv_backreferences;
2604
2605 if (av) {
2606 HvAUX(hv)->xhv_backreferences = 0;
2607 Perl_sv_kill_backrefs(aTHX_ MUTABLE_SV(hv), av);
2608 if (SvTYPE(av) == SVt_PVAV)
2609 SvREFCNT_dec_NN(av);
2610 }
2611 }
2612
2613 /*
2614 hv_iternext is implemented as a macro in hv.h
2615
2616 =for apidoc hv_iternext
2617
2618 Returns entries from a hash iterator. See C<L</hv_iterinit>>.
2619
2620 You may call C<hv_delete> or C<hv_delete_ent> on the hash entry that the
2621 iterator currently points to, without losing your place or invalidating your
2622 iterator. Note that in this case the current entry is deleted from the hash
2623 with your iterator holding the last reference to it. Your iterator is flagged
2624 to free the entry on the next call to C<hv_iternext>, so you must not discard
2625 your iterator immediately else the entry will leak - call C<hv_iternext> to
2626 trigger the resource deallocation.
2627
2628 =for apidoc hv_iternext_flags
2629
2630 Returns entries from a hash iterator. See C<L</hv_iterinit>> and
2631 C<L</hv_iternext>>.
2632 The C<flags> value will normally be zero; if C<HV_ITERNEXT_WANTPLACEHOLDERS> is
2633 set the placeholders keys (for restricted hashes) will be returned in addition
2634 to normal keys. By default placeholders are automatically skipped over.
2635 Currently a placeholder is implemented with a value that is
2636 C<&PL_sv_placeholder>. Note that the implementation of placeholders and
2637 restricted hashes may change, and the implementation currently is
2638 insufficiently abstracted for any change to be tidy.
2639
2640 =for apidoc Amnh||HV_ITERNEXT_WANTPLACEHOLDERS
2641
2642 =cut
2643 */
2644
2645 HE *
Perl_hv_iternext_flags(pTHX_ HV * hv,I32 flags)2646 Perl_hv_iternext_flags(pTHX_ HV *hv, I32 flags)
2647 {
2648 HE *entry;
2649 HE *oldentry;
2650 MAGIC* mg;
2651 struct xpvhv_aux *iter;
2652
2653 PERL_ARGS_ASSERT_HV_ITERNEXT_FLAGS;
2654
2655 if (!SvOOK(hv)) {
2656 /* Too many things (well, pp_each at least) merrily assume that you can
2657 call hv_iternext without calling hv_iterinit, so we'll have to deal
2658 with it. */
2659 hv_iterinit(hv);
2660 }
2661 iter = HvAUX(hv);
2662
2663 oldentry = entry = iter->xhv_eiter; /* HvEITER(hv) */
2664 if (SvMAGICAL(hv) && SvRMAGICAL(hv)) {
2665 if ( ( mg = mg_find((const SV *)hv, PERL_MAGIC_tied) ) ) {
2666 SV * const key = sv_newmortal();
2667 if (entry) {
2668 sv_setsv(key, HeSVKEY_force(entry));
2669 SvREFCNT_dec(HeSVKEY(entry)); /* get rid of previous key */
2670 HeSVKEY_set(entry, NULL);
2671 }
2672 else {
2673 char *k;
2674 HEK *hek;
2675
2676 /* one HE per MAGICAL hash */
2677 iter->xhv_eiter = entry = new_HE(); /* HvEITER(hv) = new_HE() */
2678 HvLAZYDEL_on(hv); /* make sure entry gets freed */
2679 Zero(entry, 1, HE);
2680 Newxz(k, HEK_BASESIZE + sizeof(const SV *), char);
2681 hek = (HEK*)k;
2682 HeKEY_hek(entry) = hek;
2683 HeKLEN(entry) = HEf_SVKEY;
2684 }
2685 magic_nextpack(MUTABLE_SV(hv),mg,key);
2686 if (SvOK(key)) {
2687 /* force key to stay around until next time */
2688 HeSVKEY_set(entry, SvREFCNT_inc_simple_NN(key));
2689 return entry; /* beware, hent_val is not set */
2690 }
2691 SvREFCNT_dec(HeVAL(entry));
2692 Safefree(HeKEY_hek(entry));
2693 del_HE(entry);
2694 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
2695 HvLAZYDEL_off(hv);
2696 return NULL;
2697 }
2698 }
2699 #if defined(DYNAMIC_ENV_FETCH) && defined(VMS) /* set up %ENV for iteration */
2700 if (!entry && SvRMAGICAL((const SV *)hv)
2701 && mg_find((const SV *)hv, PERL_MAGIC_env)) {
2702 prime_env_iter();
2703 }
2704 #endif
2705
2706 /* hv_iterinit now ensures this. */
2707 assert (HvARRAY(hv));
2708
2709 /* At start of hash, entry is NULL. */
2710 if (entry)
2711 {
2712 entry = HeNEXT(entry);
2713 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
2714 /*
2715 * Skip past any placeholders -- don't want to include them in
2716 * any iteration.
2717 */
2718 while (entry && HeVAL(entry) == &PL_sv_placeholder) {
2719 entry = HeNEXT(entry);
2720 }
2721 }
2722 }
2723
2724 #ifdef PERL_HASH_RANDOMIZE_KEYS
2725 if (iter->xhv_last_rand != iter->xhv_rand) {
2726 if (iter->xhv_riter != -1) {
2727 Perl_ck_warner_d(aTHX_ packWARN(WARN_INTERNAL),
2728 "Use of each() on hash after insertion without resetting hash iterator results in undefined behavior"
2729 pTHX__FORMAT
2730 pTHX__VALUE);
2731 }
2732 iter->xhv_last_rand = iter->xhv_rand;
2733 }
2734 #endif
2735
2736 /* Skip the entire loop if the hash is empty. */
2737 if ((flags & HV_ITERNEXT_WANTPLACEHOLDERS)
2738 ? HvTOTALKEYS(hv) : HvUSEDKEYS(hv)) {
2739 STRLEN max = HvMAX(hv);
2740 while (!entry) {
2741 /* OK. Come to the end of the current list. Grab the next one. */
2742
2743 iter->xhv_riter++; /* HvRITER(hv)++ */
2744 if (iter->xhv_riter > (I32)max /* HvRITER(hv) > HvMAX(hv) */) {
2745 /* There is no next one. End of the hash. */
2746 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
2747 #ifdef PERL_HASH_RANDOMIZE_KEYS
2748 iter->xhv_last_rand = iter->xhv_rand; /* reset xhv_last_rand so we can detect inserts during traversal */
2749 #endif
2750 break;
2751 }
2752 entry = (HvARRAY(hv))[ PERL_HASH_ITER_BUCKET(iter) & max ];
2753
2754 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
2755 /* If we have an entry, but it's a placeholder, don't count it.
2756 Try the next. */
2757 while (entry && HeVAL(entry) == &PL_sv_placeholder)
2758 entry = HeNEXT(entry);
2759 }
2760 /* Will loop again if this linked list starts NULL
2761 (for HV_ITERNEXT_WANTPLACEHOLDERS)
2762 or if we run through it and find only placeholders. */
2763 }
2764 }
2765 else {
2766 iter->xhv_riter = -1;
2767 #ifdef PERL_HASH_RANDOMIZE_KEYS
2768 iter->xhv_last_rand = iter->xhv_rand;
2769 #endif
2770 }
2771
2772 if (oldentry && HvLAZYDEL(hv)) { /* was deleted earlier? */
2773 HvLAZYDEL_off(hv);
2774 hv_free_ent(hv, oldentry);
2775 }
2776
2777 iter->xhv_eiter = entry; /* HvEITER(hv) = entry */
2778 return entry;
2779 }
2780
2781 /*
2782 =for apidoc hv_iterkey
2783
2784 Returns the key from the current position of the hash iterator. See
2785 C<L</hv_iterinit>>.
2786
2787 =cut
2788 */
2789
2790 char *
Perl_hv_iterkey(pTHX_ HE * entry,I32 * retlen)2791 Perl_hv_iterkey(pTHX_ HE *entry, I32 *retlen)
2792 {
2793 PERL_ARGS_ASSERT_HV_ITERKEY;
2794
2795 if (HeKLEN(entry) == HEf_SVKEY) {
2796 STRLEN len;
2797 char * const p = SvPV(HeKEY_sv(entry), len);
2798 *retlen = len;
2799 return p;
2800 }
2801 else {
2802 *retlen = HeKLEN(entry);
2803 return HeKEY(entry);
2804 }
2805 }
2806
2807 /* unlike hv_iterval(), this always returns a mortal copy of the key */
2808 /*
2809 =for apidoc hv_iterkeysv
2810
2811 Returns the key as an C<SV*> from the current position of the hash
2812 iterator. The return value will always be a mortal copy of the key. Also
2813 see C<L</hv_iterinit>>.
2814
2815 =cut
2816 */
2817
2818 SV *
Perl_hv_iterkeysv(pTHX_ HE * entry)2819 Perl_hv_iterkeysv(pTHX_ HE *entry)
2820 {
2821 PERL_ARGS_ASSERT_HV_ITERKEYSV;
2822
2823 return sv_2mortal(newSVhek(HeKEY_hek(entry)));
2824 }
2825
2826 /*
2827 =for apidoc hv_iterval
2828
2829 Returns the value from the current position of the hash iterator. See
2830 C<L</hv_iterkey>>.
2831
2832 =cut
2833 */
2834
2835 SV *
Perl_hv_iterval(pTHX_ HV * hv,HE * entry)2836 Perl_hv_iterval(pTHX_ HV *hv, HE *entry)
2837 {
2838 PERL_ARGS_ASSERT_HV_ITERVAL;
2839
2840 if (SvRMAGICAL(hv)) {
2841 if (mg_find((const SV *)hv, PERL_MAGIC_tied)) {
2842 SV* const sv = sv_newmortal();
2843 if (HeKLEN(entry) == HEf_SVKEY)
2844 mg_copy(MUTABLE_SV(hv), sv, (char*)HeKEY_sv(entry), HEf_SVKEY);
2845 else
2846 mg_copy(MUTABLE_SV(hv), sv, HeKEY(entry), HeKLEN(entry));
2847 return sv;
2848 }
2849 }
2850 return HeVAL(entry);
2851 }
2852
2853 /*
2854 =for apidoc hv_iternextsv
2855
2856 Performs an C<hv_iternext>, C<hv_iterkey>, and C<hv_iterval> in one
2857 operation.
2858
2859 =cut
2860 */
2861
2862 SV *
Perl_hv_iternextsv(pTHX_ HV * hv,char ** key,I32 * retlen)2863 Perl_hv_iternextsv(pTHX_ HV *hv, char **key, I32 *retlen)
2864 {
2865 HE * const he = hv_iternext_flags(hv, 0);
2866
2867 PERL_ARGS_ASSERT_HV_ITERNEXTSV;
2868
2869 if (!he)
2870 return NULL;
2871 *key = hv_iterkey(he, retlen);
2872 return hv_iterval(hv, he);
2873 }
2874
2875 /*
2876
2877 Now a macro in hv.h
2878
2879 =for apidoc hv_magic
2880
2881 Adds magic to a hash. See C<L</sv_magic>>.
2882
2883 =cut
2884 */
2885
2886 /* possibly free a shared string if no one has access to it
2887 * len and hash must both be valid for str.
2888 */
2889 void
Perl_unsharepvn(pTHX_ const char * str,I32 len,U32 hash)2890 Perl_unsharepvn(pTHX_ const char *str, I32 len, U32 hash)
2891 {
2892 unshare_hek_or_pvn (NULL, str, len, hash);
2893 }
2894
2895
2896 void
Perl_unshare_hek(pTHX_ HEK * hek)2897 Perl_unshare_hek(pTHX_ HEK *hek)
2898 {
2899 assert(hek);
2900 unshare_hek_or_pvn(hek, NULL, 0, 0);
2901 }
2902
2903 /* possibly free a shared string if no one has access to it
2904 hek if non-NULL takes priority over the other 3, else str, len and hash
2905 are used. If so, len and hash must both be valid for str.
2906 */
2907 STATIC void
S_unshare_hek_or_pvn(pTHX_ const HEK * hek,const char * str,I32 len,U32 hash)2908 S_unshare_hek_or_pvn(pTHX_ const HEK *hek, const char *str, I32 len, U32 hash)
2909 {
2910 XPVHV* xhv;
2911 HE *entry;
2912 HE **oentry;
2913 bool is_utf8 = FALSE;
2914 int k_flags = 0;
2915 const char * const save = str;
2916 struct shared_he *he = NULL;
2917
2918 if (hek) {
2919 /* Find the shared he which is just before us in memory. */
2920 he = (struct shared_he *)(((char *)hek)
2921 - STRUCT_OFFSET(struct shared_he,
2922 shared_he_hek));
2923
2924 /* Assert that the caller passed us a genuine (or at least consistent)
2925 shared hek */
2926 assert (he->shared_he_he.hent_hek == hek);
2927
2928 if (he->shared_he_he.he_valu.hent_refcount - 1) {
2929 --he->shared_he_he.he_valu.hent_refcount;
2930 return;
2931 }
2932
2933 hash = HEK_HASH(hek);
2934 } else if (len < 0) {
2935 STRLEN tmplen = -len;
2936 is_utf8 = TRUE;
2937 /* See the note in hv_fetch(). --jhi */
2938 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
2939 len = tmplen;
2940 if (is_utf8)
2941 k_flags = HVhek_UTF8;
2942 if (str != save)
2943 k_flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
2944 }
2945
2946 /* what follows was the moral equivalent of:
2947 if ((Svp = hv_fetch(PL_strtab, tmpsv, FALSE, hash))) {
2948 if (--*Svp == NULL)
2949 hv_delete(PL_strtab, str, len, G_DISCARD, hash);
2950 } */
2951 xhv = (XPVHV*)SvANY(PL_strtab);
2952 /* assert(xhv_array != 0) */
2953 oentry = &(HvARRAY(PL_strtab))[hash & (I32) HvMAX(PL_strtab)];
2954 if (he) {
2955 const HE *const he_he = &(he->shared_he_he);
2956 for (entry = *oentry; entry; oentry = &HeNEXT(entry), entry = *oentry) {
2957 if (entry == he_he)
2958 break;
2959 }
2960 } else {
2961 const int flags_masked = k_flags & HVhek_MASK;
2962 for (entry = *oentry; entry; oentry = &HeNEXT(entry), entry = *oentry) {
2963 if (HeHASH(entry) != hash) /* strings can't be equal */
2964 continue;
2965 if (HeKLEN(entry) != len)
2966 continue;
2967 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
2968 continue;
2969 if (HeKFLAGS(entry) != flags_masked)
2970 continue;
2971 break;
2972 }
2973 }
2974
2975 if (entry) {
2976 if (--entry->he_valu.hent_refcount == 0) {
2977 *oentry = HeNEXT(entry);
2978 Safefree(entry);
2979 xhv->xhv_keys--; /* HvTOTALKEYS(hv)-- */
2980 }
2981 }
2982
2983 if (!entry)
2984 Perl_ck_warner_d(aTHX_ packWARN(WARN_INTERNAL),
2985 "Attempt to free nonexistent shared string '%s'%s"
2986 pTHX__FORMAT,
2987 hek ? HEK_KEY(hek) : str,
2988 ((k_flags & HVhek_UTF8) ? " (utf8)" : "") pTHX__VALUE);
2989 if (k_flags & HVhek_FREEKEY)
2990 Safefree(str);
2991 }
2992
2993 /* get a (constant) string ptr from the global string table
2994 * string will get added if it is not already there.
2995 * len and hash must both be valid for str.
2996 */
2997 HEK *
Perl_share_hek(pTHX_ const char * str,SSize_t len,U32 hash)2998 Perl_share_hek(pTHX_ const char *str, SSize_t len, U32 hash)
2999 {
3000 bool is_utf8 = FALSE;
3001 int flags = 0;
3002 const char * const save = str;
3003
3004 PERL_ARGS_ASSERT_SHARE_HEK;
3005
3006 if (len < 0) {
3007 STRLEN tmplen = -len;
3008 is_utf8 = TRUE;
3009 /* See the note in hv_fetch(). --jhi */
3010 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
3011 len = tmplen;
3012 /* If we were able to downgrade here, then than means that we were passed
3013 in a key which only had chars 0-255, but was utf8 encoded. */
3014 if (is_utf8)
3015 flags = HVhek_UTF8;
3016 /* If we found we were able to downgrade the string to bytes, then
3017 we should flag that it needs upgrading on keys or each. Also flag
3018 that we need share_hek_flags to free the string. */
3019 if (str != save) {
3020 PERL_HASH(hash, str, len);
3021 flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
3022 }
3023 }
3024
3025 return share_hek_flags (str, len, hash, flags);
3026 }
3027
3028 STATIC HEK *
S_share_hek_flags(pTHX_ const char * str,STRLEN len,U32 hash,int flags)3029 S_share_hek_flags(pTHX_ const char *str, STRLEN len, U32 hash, int flags)
3030 {
3031 HE *entry;
3032 const int flags_masked = flags & HVhek_MASK;
3033 const U32 hindex = hash & (I32) HvMAX(PL_strtab);
3034 XPVHV * const xhv = (XPVHV*)SvANY(PL_strtab);
3035
3036 PERL_ARGS_ASSERT_SHARE_HEK_FLAGS;
3037
3038 if (UNLIKELY(len > (STRLEN) I32_MAX)) {
3039 Perl_croak_nocontext("Sorry, hash keys must be smaller than 2**31 bytes");
3040 }
3041
3042 /* what follows is the moral equivalent of:
3043
3044 if (!(Svp = hv_fetch(PL_strtab, str, len, FALSE)))
3045 hv_store(PL_strtab, str, len, NULL, hash);
3046
3047 Can't rehash the shared string table, so not sure if it's worth
3048 counting the number of entries in the linked list
3049 */
3050
3051 /* assert(xhv_array != 0) */
3052 entry = (HvARRAY(PL_strtab))[hindex];
3053 for (;entry; entry = HeNEXT(entry)) {
3054 if (HeHASH(entry) != hash) /* strings can't be equal */
3055 continue;
3056 if (HeKLEN(entry) != (SSize_t) len)
3057 continue;
3058 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
3059 continue;
3060 if (HeKFLAGS(entry) != flags_masked)
3061 continue;
3062 break;
3063 }
3064
3065 if (!entry) {
3066 /* What used to be head of the list.
3067 If this is NULL, then we're the first entry for this slot, which
3068 means we need to increate fill. */
3069 struct shared_he *new_entry;
3070 HEK *hek;
3071 char *k;
3072 HE **const head = &HvARRAY(PL_strtab)[hindex];
3073 HE *const next = *head;
3074
3075 /* We don't actually store a HE from the arena and a regular HEK.
3076 Instead we allocate one chunk of memory big enough for both,
3077 and put the HEK straight after the HE. This way we can find the
3078 HE directly from the HEK.
3079 */
3080
3081 Newx(k, STRUCT_OFFSET(struct shared_he,
3082 shared_he_hek.hek_key[0]) + len + 2, char);
3083 new_entry = (struct shared_he *)k;
3084 entry = &(new_entry->shared_he_he);
3085 hek = &(new_entry->shared_he_hek);
3086
3087 Copy(str, HEK_KEY(hek), len, char);
3088 HEK_KEY(hek)[len] = 0;
3089 HEK_LEN(hek) = len;
3090 HEK_HASH(hek) = hash;
3091 HEK_FLAGS(hek) = (unsigned char)flags_masked;
3092
3093 /* Still "point" to the HEK, so that other code need not know what
3094 we're up to. */
3095 HeKEY_hek(entry) = hek;
3096 entry->he_valu.hent_refcount = 0;
3097 HeNEXT(entry) = next;
3098 *head = entry;
3099
3100 xhv->xhv_keys++; /* HvTOTALKEYS(hv)++ */
3101 if (!next) { /* initial entry? */
3102 } else if ( DO_HSPLIT(xhv) ) {
3103 const STRLEN oldsize = xhv->xhv_max + 1;
3104 hsplit(PL_strtab, oldsize, oldsize * 2);
3105 }
3106 }
3107
3108 ++entry->he_valu.hent_refcount;
3109
3110 if (flags & HVhek_FREEKEY)
3111 Safefree(str);
3112
3113 return HeKEY_hek(entry);
3114 }
3115
3116 SSize_t *
Perl_hv_placeholders_p(pTHX_ HV * hv)3117 Perl_hv_placeholders_p(pTHX_ HV *hv)
3118 {
3119 MAGIC *mg = mg_find((const SV *)hv, PERL_MAGIC_rhash);
3120
3121 PERL_ARGS_ASSERT_HV_PLACEHOLDERS_P;
3122
3123 if (!mg) {
3124 mg = sv_magicext(MUTABLE_SV(hv), 0, PERL_MAGIC_rhash, 0, 0, 0);
3125
3126 if (!mg) {
3127 Perl_die(aTHX_ "panic: hv_placeholders_p");
3128 }
3129 }
3130 return &(mg->mg_len);
3131 }
3132
3133
3134 I32
Perl_hv_placeholders_get(pTHX_ const HV * hv)3135 Perl_hv_placeholders_get(pTHX_ const HV *hv)
3136 {
3137 MAGIC * const mg = mg_find((const SV *)hv, PERL_MAGIC_rhash);
3138
3139 PERL_ARGS_ASSERT_HV_PLACEHOLDERS_GET;
3140 PERL_UNUSED_CONTEXT;
3141
3142 return mg ? mg->mg_len : 0;
3143 }
3144
3145 void
Perl_hv_placeholders_set(pTHX_ HV * hv,I32 ph)3146 Perl_hv_placeholders_set(pTHX_ HV *hv, I32 ph)
3147 {
3148 MAGIC * const mg = mg_find((const SV *)hv, PERL_MAGIC_rhash);
3149
3150 PERL_ARGS_ASSERT_HV_PLACEHOLDERS_SET;
3151
3152 if (mg) {
3153 mg->mg_len = ph;
3154 } else if (ph) {
3155 if (!sv_magicext(MUTABLE_SV(hv), 0, PERL_MAGIC_rhash, 0, 0, ph))
3156 Perl_die(aTHX_ "panic: hv_placeholders_set");
3157 }
3158 /* else we don't need to add magic to record 0 placeholders. */
3159 }
3160
3161 STATIC SV *
S_refcounted_he_value(pTHX_ const struct refcounted_he * he)3162 S_refcounted_he_value(pTHX_ const struct refcounted_he *he)
3163 {
3164 SV *value;
3165
3166 PERL_ARGS_ASSERT_REFCOUNTED_HE_VALUE;
3167
3168 switch(he->refcounted_he_data[0] & HVrhek_typemask) {
3169 case HVrhek_undef:
3170 value = newSV(0);
3171 break;
3172 case HVrhek_delete:
3173 value = &PL_sv_placeholder;
3174 break;
3175 case HVrhek_IV:
3176 value = newSViv(he->refcounted_he_val.refcounted_he_u_iv);
3177 break;
3178 case HVrhek_UV:
3179 value = newSVuv(he->refcounted_he_val.refcounted_he_u_uv);
3180 break;
3181 case HVrhek_PV:
3182 case HVrhek_PV_UTF8:
3183 /* Create a string SV that directly points to the bytes in our
3184 structure. */
3185 value = newSV_type(SVt_PV);
3186 SvPV_set(value, (char *) he->refcounted_he_data + 1);
3187 SvCUR_set(value, he->refcounted_he_val.refcounted_he_u_len);
3188 /* This stops anything trying to free it */
3189 SvLEN_set(value, 0);
3190 SvPOK_on(value);
3191 SvREADONLY_on(value);
3192 if ((he->refcounted_he_data[0] & HVrhek_typemask) == HVrhek_PV_UTF8)
3193 SvUTF8_on(value);
3194 break;
3195 default:
3196 Perl_croak(aTHX_ "panic: refcounted_he_value bad flags %" UVxf,
3197 (UV)he->refcounted_he_data[0]);
3198 }
3199 return value;
3200 }
3201
3202 /*
3203 =for apidoc refcounted_he_chain_2hv
3204
3205 Generates and returns a C<HV *> representing the content of a
3206 C<refcounted_he> chain.
3207 C<flags> is currently unused and must be zero.
3208
3209 =cut
3210 */
3211 HV *
Perl_refcounted_he_chain_2hv(pTHX_ const struct refcounted_he * chain,U32 flags)3212 Perl_refcounted_he_chain_2hv(pTHX_ const struct refcounted_he *chain, U32 flags)
3213 {
3214 HV *hv;
3215 U32 placeholders, max;
3216
3217 if (flags)
3218 Perl_croak(aTHX_ "panic: refcounted_he_chain_2hv bad flags %" UVxf,
3219 (UV)flags);
3220
3221 /* We could chase the chain once to get an idea of the number of keys,
3222 and call ksplit. But for now we'll make a potentially inefficient
3223 hash with only 8 entries in its array. */
3224 hv = newHV();
3225 max = HvMAX(hv);
3226 if (!HvARRAY(hv)) {
3227 char *array;
3228 Newxz(array, PERL_HV_ARRAY_ALLOC_BYTES(max + 1), char);
3229 HvARRAY(hv) = (HE**)array;
3230 }
3231
3232 placeholders = 0;
3233 while (chain) {
3234 #ifdef USE_ITHREADS
3235 U32 hash = chain->refcounted_he_hash;
3236 #else
3237 U32 hash = HEK_HASH(chain->refcounted_he_hek);
3238 #endif
3239 HE **oentry = &((HvARRAY(hv))[hash & max]);
3240 HE *entry = *oentry;
3241 SV *value;
3242
3243 for (; entry; entry = HeNEXT(entry)) {
3244 if (HeHASH(entry) == hash) {
3245 /* We might have a duplicate key here. If so, entry is older
3246 than the key we've already put in the hash, so if they are
3247 the same, skip adding entry. */
3248 #ifdef USE_ITHREADS
3249 const STRLEN klen = HeKLEN(entry);
3250 const char *const key = HeKEY(entry);
3251 if (klen == chain->refcounted_he_keylen
3252 && (!!HeKUTF8(entry)
3253 == !!(chain->refcounted_he_data[0] & HVhek_UTF8))
3254 && memEQ(key, REF_HE_KEY(chain), klen))
3255 goto next_please;
3256 #else
3257 if (HeKEY_hek(entry) == chain->refcounted_he_hek)
3258 goto next_please;
3259 if (HeKLEN(entry) == HEK_LEN(chain->refcounted_he_hek)
3260 && HeKUTF8(entry) == HEK_UTF8(chain->refcounted_he_hek)
3261 && memEQ(HeKEY(entry), HEK_KEY(chain->refcounted_he_hek),
3262 HeKLEN(entry)))
3263 goto next_please;
3264 #endif
3265 }
3266 }
3267 assert (!entry);
3268 entry = new_HE();
3269
3270 #ifdef USE_ITHREADS
3271 HeKEY_hek(entry)
3272 = share_hek_flags(REF_HE_KEY(chain),
3273 chain->refcounted_he_keylen,
3274 chain->refcounted_he_hash,
3275 (chain->refcounted_he_data[0]
3276 & (HVhek_UTF8|HVhek_WASUTF8)));
3277 #else
3278 HeKEY_hek(entry) = share_hek_hek(chain->refcounted_he_hek);
3279 #endif
3280 value = refcounted_he_value(chain);
3281 if (value == &PL_sv_placeholder)
3282 placeholders++;
3283 HeVAL(entry) = value;
3284
3285 /* Link it into the chain. */
3286 HeNEXT(entry) = *oentry;
3287 *oentry = entry;
3288
3289 HvTOTALKEYS(hv)++;
3290
3291 next_please:
3292 chain = chain->refcounted_he_next;
3293 }
3294
3295 if (placeholders) {
3296 clear_placeholders(hv, placeholders);
3297 }
3298
3299 /* We could check in the loop to see if we encounter any keys with key
3300 flags, but it's probably not worth it, as this per-hash flag is only
3301 really meant as an optimisation for things like Storable. */
3302 HvHASKFLAGS_on(hv);
3303 DEBUG_A(Perl_hv_assert(aTHX_ hv));
3304
3305 return hv;
3306 }
3307
3308 /*
3309 =for apidoc refcounted_he_fetch_pvn
3310
3311 Search along a C<refcounted_he> chain for an entry with the key specified
3312 by C<keypv> and C<keylen>. If C<flags> has the C<REFCOUNTED_HE_KEY_UTF8>
3313 bit set, the key octets are interpreted as UTF-8, otherwise they
3314 are interpreted as Latin-1. C<hash> is a precomputed hash of the key
3315 string, or zero if it has not been precomputed. Returns a mortal scalar
3316 representing the value associated with the key, or C<&PL_sv_placeholder>
3317 if there is no value associated with the key.
3318
3319 =cut
3320 */
3321
3322 SV *
Perl_refcounted_he_fetch_pvn(pTHX_ const struct refcounted_he * chain,const char * keypv,STRLEN keylen,U32 hash,U32 flags)3323 Perl_refcounted_he_fetch_pvn(pTHX_ const struct refcounted_he *chain,
3324 const char *keypv, STRLEN keylen, U32 hash, U32 flags)
3325 {
3326 U8 utf8_flag;
3327 PERL_ARGS_ASSERT_REFCOUNTED_HE_FETCH_PVN;
3328
3329 if (flags & ~(REFCOUNTED_HE_KEY_UTF8|REFCOUNTED_HE_EXISTS))
3330 Perl_croak(aTHX_ "panic: refcounted_he_fetch_pvn bad flags %" UVxf,
3331 (UV)flags);
3332 if (!chain)
3333 goto ret;
3334 if (flags & REFCOUNTED_HE_KEY_UTF8) {
3335 /* For searching purposes, canonicalise to Latin-1 where possible. */
3336 const char *keyend = keypv + keylen, *p;
3337 STRLEN nonascii_count = 0;
3338 for (p = keypv; p != keyend; p++) {
3339 if (! UTF8_IS_INVARIANT(*p)) {
3340 if (! UTF8_IS_NEXT_CHAR_DOWNGRADEABLE(p, keyend)) {
3341 goto canonicalised_key;
3342 }
3343 nonascii_count++;
3344 p++;
3345 }
3346 }
3347 if (nonascii_count) {
3348 char *q;
3349 const char *p = keypv, *keyend = keypv + keylen;
3350 keylen -= nonascii_count;
3351 Newx(q, keylen, char);
3352 SAVEFREEPV(q);
3353 keypv = q;
3354 for (; p != keyend; p++, q++) {
3355 U8 c = (U8)*p;
3356 if (UTF8_IS_INVARIANT(c)) {
3357 *q = (char) c;
3358 }
3359 else {
3360 p++;
3361 *q = (char) EIGHT_BIT_UTF8_TO_NATIVE(c, *p);
3362 }
3363 }
3364 }
3365 flags &= ~REFCOUNTED_HE_KEY_UTF8;
3366 canonicalised_key: ;
3367 }
3368 utf8_flag = (flags & REFCOUNTED_HE_KEY_UTF8) ? HVhek_UTF8 : 0;
3369 if (!hash)
3370 PERL_HASH(hash, keypv, keylen);
3371
3372 for (; chain; chain = chain->refcounted_he_next) {
3373 if (
3374 #ifdef USE_ITHREADS
3375 hash == chain->refcounted_he_hash &&
3376 keylen == chain->refcounted_he_keylen &&
3377 memEQ(REF_HE_KEY(chain), keypv, keylen) &&
3378 utf8_flag == (chain->refcounted_he_data[0] & HVhek_UTF8)
3379 #else
3380 hash == HEK_HASH(chain->refcounted_he_hek) &&
3381 keylen == (STRLEN)HEK_LEN(chain->refcounted_he_hek) &&
3382 memEQ(HEK_KEY(chain->refcounted_he_hek), keypv, keylen) &&
3383 utf8_flag == (HEK_FLAGS(chain->refcounted_he_hek) & HVhek_UTF8)
3384 #endif
3385 ) {
3386 if (flags & REFCOUNTED_HE_EXISTS)
3387 return (chain->refcounted_he_data[0] & HVrhek_typemask)
3388 == HVrhek_delete
3389 ? NULL : &PL_sv_yes;
3390 return sv_2mortal(refcounted_he_value(chain));
3391 }
3392 }
3393 ret:
3394 return flags & REFCOUNTED_HE_EXISTS ? NULL : &PL_sv_placeholder;
3395 }
3396
3397 /*
3398 =for apidoc refcounted_he_fetch_pv
3399
3400 Like L</refcounted_he_fetch_pvn>, but takes a nul-terminated string
3401 instead of a string/length pair.
3402
3403 =cut
3404 */
3405
3406 SV *
Perl_refcounted_he_fetch_pv(pTHX_ const struct refcounted_he * chain,const char * key,U32 hash,U32 flags)3407 Perl_refcounted_he_fetch_pv(pTHX_ const struct refcounted_he *chain,
3408 const char *key, U32 hash, U32 flags)
3409 {
3410 PERL_ARGS_ASSERT_REFCOUNTED_HE_FETCH_PV;
3411 return refcounted_he_fetch_pvn(chain, key, strlen(key), hash, flags);
3412 }
3413
3414 /*
3415 =for apidoc refcounted_he_fetch_sv
3416
3417 Like L</refcounted_he_fetch_pvn>, but takes a Perl scalar instead of a
3418 string/length pair.
3419
3420 =cut
3421 */
3422
3423 SV *
Perl_refcounted_he_fetch_sv(pTHX_ const struct refcounted_he * chain,SV * key,U32 hash,U32 flags)3424 Perl_refcounted_he_fetch_sv(pTHX_ const struct refcounted_he *chain,
3425 SV *key, U32 hash, U32 flags)
3426 {
3427 const char *keypv;
3428 STRLEN keylen;
3429 PERL_ARGS_ASSERT_REFCOUNTED_HE_FETCH_SV;
3430 if (flags & REFCOUNTED_HE_KEY_UTF8)
3431 Perl_croak(aTHX_ "panic: refcounted_he_fetch_sv bad flags %" UVxf,
3432 (UV)flags);
3433 keypv = SvPV_const(key, keylen);
3434 if (SvUTF8(key))
3435 flags |= REFCOUNTED_HE_KEY_UTF8;
3436 if (!hash && SvIsCOW_shared_hash(key))
3437 hash = SvSHARED_HASH(key);
3438 return refcounted_he_fetch_pvn(chain, keypv, keylen, hash, flags);
3439 }
3440
3441 /*
3442 =for apidoc refcounted_he_new_pvn
3443
3444 Creates a new C<refcounted_he>. This consists of a single key/value
3445 pair and a reference to an existing C<refcounted_he> chain (which may
3446 be empty), and thus forms a longer chain. When using the longer chain,
3447 the new key/value pair takes precedence over any entry for the same key
3448 further along the chain.
3449
3450 The new key is specified by C<keypv> and C<keylen>. If C<flags> has
3451 the C<REFCOUNTED_HE_KEY_UTF8> bit set, the key octets are interpreted
3452 as UTF-8, otherwise they are interpreted as Latin-1. C<hash> is
3453 a precomputed hash of the key string, or zero if it has not been
3454 precomputed.
3455
3456 C<value> is the scalar value to store for this key. C<value> is copied
3457 by this function, which thus does not take ownership of any reference
3458 to it, and later changes to the scalar will not be reflected in the
3459 value visible in the C<refcounted_he>. Complex types of scalar will not
3460 be stored with referential integrity, but will be coerced to strings.
3461 C<value> may be either null or C<&PL_sv_placeholder> to indicate that no
3462 value is to be associated with the key; this, as with any non-null value,
3463 takes precedence over the existence of a value for the key further along
3464 the chain.
3465
3466 C<parent> points to the rest of the C<refcounted_he> chain to be
3467 attached to the new C<refcounted_he>. This function takes ownership
3468 of one reference to C<parent>, and returns one reference to the new
3469 C<refcounted_he>.
3470
3471 =cut
3472 */
3473
3474 struct refcounted_he *
Perl_refcounted_he_new_pvn(pTHX_ struct refcounted_he * parent,const char * keypv,STRLEN keylen,U32 hash,SV * value,U32 flags)3475 Perl_refcounted_he_new_pvn(pTHX_ struct refcounted_he *parent,
3476 const char *keypv, STRLEN keylen, U32 hash, SV *value, U32 flags)
3477 {
3478 STRLEN value_len = 0;
3479 const char *value_p = NULL;
3480 bool is_pv;
3481 char value_type;
3482 char hekflags;
3483 STRLEN key_offset = 1;
3484 struct refcounted_he *he;
3485 PERL_ARGS_ASSERT_REFCOUNTED_HE_NEW_PVN;
3486
3487 if (!value || value == &PL_sv_placeholder) {
3488 value_type = HVrhek_delete;
3489 } else if (SvPOK(value)) {
3490 value_type = HVrhek_PV;
3491 } else if (SvIOK(value)) {
3492 value_type = SvUOK((const SV *)value) ? HVrhek_UV : HVrhek_IV;
3493 } else if (!SvOK(value)) {
3494 value_type = HVrhek_undef;
3495 } else {
3496 value_type = HVrhek_PV;
3497 }
3498 is_pv = value_type == HVrhek_PV;
3499 if (is_pv) {
3500 /* Do it this way so that the SvUTF8() test is after the SvPV, in case
3501 the value is overloaded, and doesn't yet have the UTF-8flag set. */
3502 value_p = SvPV_const(value, value_len);
3503 if (SvUTF8(value))
3504 value_type = HVrhek_PV_UTF8;
3505 key_offset = value_len + 2;
3506 }
3507 hekflags = value_type;
3508
3509 if (flags & REFCOUNTED_HE_KEY_UTF8) {
3510 /* Canonicalise to Latin-1 where possible. */
3511 const char *keyend = keypv + keylen, *p;
3512 STRLEN nonascii_count = 0;
3513 for (p = keypv; p != keyend; p++) {
3514 if (! UTF8_IS_INVARIANT(*p)) {
3515 if (! UTF8_IS_NEXT_CHAR_DOWNGRADEABLE(p, keyend)) {
3516 goto canonicalised_key;
3517 }
3518 nonascii_count++;
3519 p++;
3520 }
3521 }
3522 if (nonascii_count) {
3523 char *q;
3524 const char *p = keypv, *keyend = keypv + keylen;
3525 keylen -= nonascii_count;
3526 Newx(q, keylen, char);
3527 SAVEFREEPV(q);
3528 keypv = q;
3529 for (; p != keyend; p++, q++) {
3530 U8 c = (U8)*p;
3531 if (UTF8_IS_INVARIANT(c)) {
3532 *q = (char) c;
3533 }
3534 else {
3535 p++;
3536 *q = (char) EIGHT_BIT_UTF8_TO_NATIVE(c, *p);
3537 }
3538 }
3539 }
3540 flags &= ~REFCOUNTED_HE_KEY_UTF8;
3541 canonicalised_key: ;
3542 }
3543 if (flags & REFCOUNTED_HE_KEY_UTF8)
3544 hekflags |= HVhek_UTF8;
3545 if (!hash)
3546 PERL_HASH(hash, keypv, keylen);
3547
3548 #ifdef USE_ITHREADS
3549 he = (struct refcounted_he*)
3550 PerlMemShared_malloc(sizeof(struct refcounted_he) - 1
3551 + keylen
3552 + key_offset);
3553 #else
3554 he = (struct refcounted_he*)
3555 PerlMemShared_malloc(sizeof(struct refcounted_he) - 1
3556 + key_offset);
3557 #endif
3558
3559 he->refcounted_he_next = parent;
3560
3561 if (is_pv) {
3562 Copy(value_p, he->refcounted_he_data + 1, value_len + 1, char);
3563 he->refcounted_he_val.refcounted_he_u_len = value_len;
3564 } else if (value_type == HVrhek_IV) {
3565 he->refcounted_he_val.refcounted_he_u_iv = SvIVX(value);
3566 } else if (value_type == HVrhek_UV) {
3567 he->refcounted_he_val.refcounted_he_u_uv = SvUVX(value);
3568 }
3569
3570 #ifdef USE_ITHREADS
3571 he->refcounted_he_hash = hash;
3572 he->refcounted_he_keylen = keylen;
3573 Copy(keypv, he->refcounted_he_data + key_offset, keylen, char);
3574 #else
3575 he->refcounted_he_hek = share_hek_flags(keypv, keylen, hash, hekflags);
3576 #endif
3577
3578 he->refcounted_he_data[0] = hekflags;
3579 he->refcounted_he_refcnt = 1;
3580
3581 return he;
3582 }
3583
3584 /*
3585 =for apidoc refcounted_he_new_pv
3586
3587 Like L</refcounted_he_new_pvn>, but takes a nul-terminated string instead
3588 of a string/length pair.
3589
3590 =cut
3591 */
3592
3593 struct refcounted_he *
Perl_refcounted_he_new_pv(pTHX_ struct refcounted_he * parent,const char * key,U32 hash,SV * value,U32 flags)3594 Perl_refcounted_he_new_pv(pTHX_ struct refcounted_he *parent,
3595 const char *key, U32 hash, SV *value, U32 flags)
3596 {
3597 PERL_ARGS_ASSERT_REFCOUNTED_HE_NEW_PV;
3598 return refcounted_he_new_pvn(parent, key, strlen(key), hash, value, flags);
3599 }
3600
3601 /*
3602 =for apidoc refcounted_he_new_sv
3603
3604 Like L</refcounted_he_new_pvn>, but takes a Perl scalar instead of a
3605 string/length pair.
3606
3607 =cut
3608 */
3609
3610 struct refcounted_he *
Perl_refcounted_he_new_sv(pTHX_ struct refcounted_he * parent,SV * key,U32 hash,SV * value,U32 flags)3611 Perl_refcounted_he_new_sv(pTHX_ struct refcounted_he *parent,
3612 SV *key, U32 hash, SV *value, U32 flags)
3613 {
3614 const char *keypv;
3615 STRLEN keylen;
3616 PERL_ARGS_ASSERT_REFCOUNTED_HE_NEW_SV;
3617 if (flags & REFCOUNTED_HE_KEY_UTF8)
3618 Perl_croak(aTHX_ "panic: refcounted_he_new_sv bad flags %" UVxf,
3619 (UV)flags);
3620 keypv = SvPV_const(key, keylen);
3621 if (SvUTF8(key))
3622 flags |= REFCOUNTED_HE_KEY_UTF8;
3623 if (!hash && SvIsCOW_shared_hash(key))
3624 hash = SvSHARED_HASH(key);
3625 return refcounted_he_new_pvn(parent, keypv, keylen, hash, value, flags);
3626 }
3627
3628 /*
3629 =for apidoc refcounted_he_free
3630
3631 Decrements the reference count of a C<refcounted_he> by one. If the
3632 reference count reaches zero the structure's memory is freed, which
3633 (recursively) causes a reduction of its parent C<refcounted_he>'s
3634 reference count. It is safe to pass a null pointer to this function:
3635 no action occurs in this case.
3636
3637 =cut
3638 */
3639
3640 void
Perl_refcounted_he_free(pTHX_ struct refcounted_he * he)3641 Perl_refcounted_he_free(pTHX_ struct refcounted_he *he) {
3642 PERL_UNUSED_CONTEXT;
3643
3644 while (he) {
3645 struct refcounted_he *copy;
3646 U32 new_count;
3647
3648 HINTS_REFCNT_LOCK;
3649 new_count = --he->refcounted_he_refcnt;
3650 HINTS_REFCNT_UNLOCK;
3651
3652 if (new_count) {
3653 return;
3654 }
3655
3656 #ifndef USE_ITHREADS
3657 unshare_hek_or_pvn (he->refcounted_he_hek, 0, 0, 0);
3658 #endif
3659 copy = he;
3660 he = he->refcounted_he_next;
3661 PerlMemShared_free(copy);
3662 }
3663 }
3664
3665 /*
3666 =for apidoc refcounted_he_inc
3667
3668 Increment the reference count of a C<refcounted_he>. The pointer to the
3669 C<refcounted_he> is also returned. It is safe to pass a null pointer
3670 to this function: no action occurs and a null pointer is returned.
3671
3672 =cut
3673 */
3674
3675 struct refcounted_he *
Perl_refcounted_he_inc(pTHX_ struct refcounted_he * he)3676 Perl_refcounted_he_inc(pTHX_ struct refcounted_he *he)
3677 {
3678 PERL_UNUSED_CONTEXT;
3679 if (he) {
3680 HINTS_REFCNT_LOCK;
3681 he->refcounted_he_refcnt++;
3682 HINTS_REFCNT_UNLOCK;
3683 }
3684 return he;
3685 }
3686
3687 /*
3688 =for apidoc_section $COP
3689 =for apidoc cop_fetch_label
3690
3691 Returns the label attached to a cop, and stores its length in bytes into
3692 C<*len>.
3693 Upon return, C<*flags> will be set to either C<SVf_UTF8> or 0.
3694
3695 Alternatively, use the macro C<L</CopLABEL_len_flags>>;
3696 or if you don't need to know if the label is UTF-8 or not, the macro
3697 C<L</CopLABEL_len>>;
3698 or if you additionally dont need to know the length, C<L</CopLABEL>>.
3699
3700 =cut
3701 */
3702
3703 /* pp_entereval is aware that labels are stored with a key ':' at the top of
3704 the linked list. */
3705 const char *
Perl_cop_fetch_label(pTHX_ COP * const cop,STRLEN * len,U32 * flags)3706 Perl_cop_fetch_label(pTHX_ COP *const cop, STRLEN *len, U32 *flags) {
3707 struct refcounted_he *const chain = cop->cop_hints_hash;
3708
3709 PERL_ARGS_ASSERT_COP_FETCH_LABEL;
3710 PERL_UNUSED_CONTEXT;
3711
3712 if (!chain)
3713 return NULL;
3714 #ifdef USE_ITHREADS
3715 if (chain->refcounted_he_keylen != 1)
3716 return NULL;
3717 if (*REF_HE_KEY(chain) != ':')
3718 return NULL;
3719 #else
3720 if ((STRLEN)HEK_LEN(chain->refcounted_he_hek) != 1)
3721 return NULL;
3722 if (*HEK_KEY(chain->refcounted_he_hek) != ':')
3723 return NULL;
3724 #endif
3725 /* Stop anyone trying to really mess us up by adding their own value for
3726 ':' into %^H */
3727 if ((chain->refcounted_he_data[0] & HVrhek_typemask) != HVrhek_PV
3728 && (chain->refcounted_he_data[0] & HVrhek_typemask) != HVrhek_PV_UTF8)
3729 return NULL;
3730
3731 if (len)
3732 *len = chain->refcounted_he_val.refcounted_he_u_len;
3733 if (flags) {
3734 *flags = ((chain->refcounted_he_data[0] & HVrhek_typemask)
3735 == HVrhek_PV_UTF8) ? SVf_UTF8 : 0;
3736 }
3737 return chain->refcounted_he_data + 1;
3738 }
3739
3740 /*
3741 =for apidoc cop_store_label
3742
3743 Save a label into a C<cop_hints_hash>.
3744 You need to set flags to C<SVf_UTF8>
3745 for a UTF-8 label. Any other flag is ignored.
3746
3747 =cut
3748 */
3749
3750 void
Perl_cop_store_label(pTHX_ COP * const cop,const char * label,STRLEN len,U32 flags)3751 Perl_cop_store_label(pTHX_ COP *const cop, const char *label, STRLEN len,
3752 U32 flags)
3753 {
3754 SV *labelsv;
3755 PERL_ARGS_ASSERT_COP_STORE_LABEL;
3756
3757 if (flags & ~(SVf_UTF8))
3758 Perl_croak(aTHX_ "panic: cop_store_label illegal flag bits 0x%" UVxf,
3759 (UV)flags);
3760 labelsv = newSVpvn_flags(label, len, SVs_TEMP);
3761 if (flags & SVf_UTF8)
3762 SvUTF8_on(labelsv);
3763 cop->cop_hints_hash
3764 = refcounted_he_new_pvs(cop->cop_hints_hash, ":", labelsv, 0);
3765 }
3766
3767 /*
3768 =for apidoc_section $HV
3769 =for apidoc hv_assert
3770
3771 Check that a hash is in an internally consistent state.
3772
3773 =cut
3774 */
3775
3776 #ifdef DEBUGGING
3777
3778 void
Perl_hv_assert(pTHX_ HV * hv)3779 Perl_hv_assert(pTHX_ HV *hv)
3780 {
3781 HE* entry;
3782 int withflags = 0;
3783 int placeholders = 0;
3784 int real = 0;
3785 int bad = 0;
3786 const I32 riter = HvRITER_get(hv);
3787 HE *eiter = HvEITER_get(hv);
3788
3789 PERL_ARGS_ASSERT_HV_ASSERT;
3790
3791 (void)hv_iterinit(hv);
3792
3793 while ((entry = hv_iternext_flags(hv, HV_ITERNEXT_WANTPLACEHOLDERS))) {
3794 /* sanity check the values */
3795 if (HeVAL(entry) == &PL_sv_placeholder)
3796 placeholders++;
3797 else
3798 real++;
3799 /* sanity check the keys */
3800 if (HeSVKEY(entry)) {
3801 NOOP; /* Don't know what to check on SV keys. */
3802 } else if (HeKUTF8(entry)) {
3803 withflags++;
3804 if (HeKWASUTF8(entry)) {
3805 PerlIO_printf(Perl_debug_log,
3806 "hash key has both WASUTF8 and UTF8: '%.*s'\n",
3807 (int) HeKLEN(entry), HeKEY(entry));
3808 bad = 1;
3809 }
3810 } else if (HeKWASUTF8(entry))
3811 withflags++;
3812 }
3813 if (!SvTIED_mg((const SV *)hv, PERL_MAGIC_tied)) {
3814 static const char bad_count[] = "Count %d %s(s), but hash reports %d\n";
3815 const int nhashkeys = HvUSEDKEYS(hv);
3816 const int nhashplaceholders = HvPLACEHOLDERS_get(hv);
3817
3818 if (nhashkeys != real) {
3819 PerlIO_printf(Perl_debug_log, bad_count, real, "keys", nhashkeys );
3820 bad = 1;
3821 }
3822 if (nhashplaceholders != placeholders) {
3823 PerlIO_printf(Perl_debug_log, bad_count, placeholders, "placeholder", nhashplaceholders );
3824 bad = 1;
3825 }
3826 }
3827 if (withflags && ! HvHASKFLAGS(hv)) {
3828 PerlIO_printf(Perl_debug_log,
3829 "Hash has HASKFLAGS off but I count %d key(s) with flags\n",
3830 withflags);
3831 bad = 1;
3832 }
3833 if (bad) {
3834 sv_dump(MUTABLE_SV(hv));
3835 }
3836 HvRITER_set(hv, riter); /* Restore hash iterator state */
3837 HvEITER_set(hv, eiter);
3838 }
3839
3840 #endif
3841
3842 /*
3843 * ex: set ts=8 sts=4 sw=4 et:
3844 */
3845