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 #define DEBUG_HASH_RAND_BITS (DEBUG_h_TEST)
53
54 /* Algorithm "xor" from p. 4 of Marsaglia, "Xorshift RNGs"
55 * See also https://en.wikipedia.org/wiki/Xorshift
56 */
57 #if IVSIZE == 8
58 /* 64 bit version */
59 #define XORSHIFT_RAND_BITS(x) PERL_XORSHIFT64_A(x)
60 #else
61 /* 32 bit version */
62 #define XORSHIFT_RAND_BITS(x) PERL_XORSHIFT32_A(x)
63 #endif
64
65 #define UPDATE_HASH_RAND_BITS_KEY(key,klen) \
66 STMT_START { \
67 XORSHIFT_RAND_BITS(PL_hash_rand_bits); \
68 if (DEBUG_HASH_RAND_BITS) { \
69 PerlIO_printf( Perl_debug_log, \
70 "PL_hash_rand_bits=%016" UVxf" @ %s:%-4d", \
71 (UV)PL_hash_rand_bits, __FILE__, __LINE__ \
72 ); \
73 if (DEBUG_v_TEST && key) { \
74 PerlIO_printf( Perl_debug_log, " key:'%.*s' %" UVuf"\n", \
75 (int)klen, \
76 key ? key : "", /* silence warning */ \
77 (UV)klen \
78 ); \
79 } else { \
80 PerlIO_printf( Perl_debug_log, "\n"); \
81 } \
82 } \
83 } STMT_END
84
85 #define MAYBE_UPDATE_HASH_RAND_BITS_KEY(key,klen) \
86 STMT_START { \
87 if (PL_HASH_RAND_BITS_ENABLED) \
88 UPDATE_HASH_RAND_BITS_KEY(key,klen); \
89 } STMT_END
90
91
92 #define UPDATE_HASH_RAND_BITS() \
93 UPDATE_HASH_RAND_BITS_KEY(NULL,0)
94
95 #define MAYBE_UPDATE_HASH_RAND_BITS() \
96 MAYBE_UPDATE_HASH_RAND_BITS_KEY(NULL,0)
97
98 /* HeKFLAGS(entry) is a single U8, so only provides 8 flags bits.
99 We currently use 3. All 3 we have behave differently, so if we find a use for
100 more flags it's hard to predict which they group with.
101
102 Hash keys are stored as flat octet sequences, not SVs. Hence we need a flag
103 bit to say whether those octet sequences represent ISO-8859-1 or UTF-8 -
104 HVhek_UTF8. The value of this flag bit matters for (regular) hash key
105 lookups.
106
107 To speed up comparisons, keys are normalised to octets. But we (also)
108 preserve whether the key was supplied, so we need another flag bit to say
109 whether to reverse the normalisation when iterating the keys (converting them
110 back to SVs) - HVhek_WASUTF8. The value of this flag bit must be ignored for
111 (regular) hash key lookups.
112
113 But for the shared string table (the private "hash" that manages shared hash
114 keys and their reference counts), we need to be able to store both variants
115 (HVhek_WASUTF8 set and clear), so the code performing lookups in this hash
116 must be different and consider both keys.
117
118 However, regular hashes (now) can have a mix of shared and unshared keys.
119 (This avoids the need to reallocate all the keys into unshared storage at
120 the point where hash passes the "large" hash threshold, and no longer uses
121 the shared string table - existing keys remain shared, to avoid makework.)
122
123 Meaning that HVhek_NOTSHARED *may* be set in regular hashes (but should be
124 ignored for hash lookups) but must always be clear in the keys in the shared
125 string table (because the pointers to these keys are directly copied into
126 regular hashes - this is how shared keys work.)
127
128 Hence all 3 are different, and it's hard to predict the best way to future
129 proof what is needed next.
130
131 We also have HVhek_ENABLEHVKFLAGS, which is used as a mask within the code
132 below to determine whether to set HvHASKFLAGS() true on the hash as a whole.
133 This is a public "optimisation" flag provided to serealisers, to indicate
134 (up front) that a hash contains non-8-bit keys, if they want to use different
135 storage formats for hashes where all keys are simple octet sequences
136 (avoiding needing to store an extra byte per hash key), and they need to know
137 that this holds *before* iterating the hash keys. Only Storable seems to use
138 this. (For this use case, HVhek_NOTSHARED doesn't matter)
139
140 For now, we assume that any future flag bits will need to be distinguished
141 in the shared string table, hence we create this mask for the shared string
142 table code. It happens to be the same as HVhek_ENABLEHVKFLAGS, but that might
143 change if we add a flag bit that matters to the shared string table but not
144 to Storable (or similar). */
145
146 #define HVhek_STORAGE_MASK (0xFF & ~HVhek_NOTSHARED)
147
148 #ifdef PURIFY
149
150 #define new_HE() (HE*)safemalloc(sizeof(HE))
151 #define del_HE(p) safefree((char*)p)
152
153 #else
154
155 STATIC HE*
S_new_he(pTHX)156 S_new_he(pTHX)
157 {
158 HE* he;
159 void ** const root = &PL_body_roots[HE_ARENA_ROOT_IX];
160
161 if (!*root)
162 Perl_more_bodies(aTHX_ HE_ARENA_ROOT_IX, sizeof(HE), PERL_ARENA_SIZE);
163 he = (HE*) *root;
164 assert(he);
165 *root = HeNEXT(he);
166 return he;
167 }
168
169 #define new_HE() new_he()
170 #define del_HE(p) \
171 STMT_START { \
172 HeNEXT(p) = (HE*)(PL_body_roots[HE_ARENA_ROOT_IX]); \
173 PL_body_roots[HE_ARENA_ROOT_IX] = p; \
174 } STMT_END
175
176
177
178 #endif
179
180 STATIC HEK *
S_save_hek_flags(const char * str,I32 len,U32 hash,int flags)181 S_save_hek_flags(const char *str, I32 len, U32 hash, int flags)
182 {
183 char *k;
184 HEK *hek;
185
186 PERL_ARGS_ASSERT_SAVE_HEK_FLAGS;
187
188 Newx(k, HEK_BASESIZE + len + 2, char);
189 hek = (HEK*)k;
190 Copy(str, HEK_KEY(hek), len, char);
191 HEK_KEY(hek)[len] = 0;
192 HEK_LEN(hek) = len;
193 HEK_HASH(hek) = hash;
194 HEK_FLAGS(hek) = HVhek_NOTSHARED | (flags & HVhek_STORAGE_MASK);
195
196 if (flags & HVhek_FREEKEY)
197 Safefree(str);
198 return hek;
199 }
200
201 /* free the pool of temporary HE/HEK pairs returned by hv_fetch_ent
202 * for tied hashes */
203
204 void
Perl_free_tied_hv_pool(pTHX)205 Perl_free_tied_hv_pool(pTHX)
206 {
207 HE *he = PL_hv_fetch_ent_mh;
208 while (he) {
209 HE * const ohe = he;
210 Safefree(HeKEY_hek(he));
211 he = HeNEXT(he);
212 del_HE(ohe);
213 }
214 PL_hv_fetch_ent_mh = NULL;
215 }
216
217 #if defined(USE_ITHREADS)
218 HEK *
Perl_hek_dup(pTHX_ HEK * source,CLONE_PARAMS * param)219 Perl_hek_dup(pTHX_ HEK *source, CLONE_PARAMS* param)
220 {
221 HEK *shared;
222
223 PERL_ARGS_ASSERT_HEK_DUP;
224 PERL_UNUSED_ARG(param);
225
226 if (!source)
227 return NULL;
228
229 shared = (HEK*)ptr_table_fetch(PL_ptr_table, source);
230 if (shared) {
231 /* We already shared this hash key. */
232 (void)share_hek_hek(shared);
233 }
234 else {
235 shared
236 = share_hek_flags(HEK_KEY(source), HEK_LEN(source),
237 HEK_HASH(source), HEK_FLAGS(source));
238 ptr_table_store(PL_ptr_table, source, shared);
239 }
240 return shared;
241 }
242
243 HE *
Perl_he_dup(pTHX_ const HE * e,bool shared,CLONE_PARAMS * param)244 Perl_he_dup(pTHX_ const HE *e, bool shared, CLONE_PARAMS* param)
245 {
246 HE *ret;
247
248 PERL_ARGS_ASSERT_HE_DUP;
249
250 /* All the *_dup functions are deemed to be API, despite most being deeply
251 tied to the internals. Hence we can't simply remove the parameter
252 "shared" from this function. */
253 /* sv_dup and sv_dup_inc seem to be the only two that are used by XS code.
254 Probably the others should be dropped from the API. See #19409 */
255 PERL_UNUSED_ARG(shared);
256
257 if (!e)
258 return NULL;
259 /* look for it in the table first */
260 ret = (HE*)ptr_table_fetch(PL_ptr_table, e);
261 if (ret)
262 return ret;
263
264 /* create anew and remember what it is */
265 ret = new_HE();
266 ptr_table_store(PL_ptr_table, e, ret);
267
268 if (HeKLEN(e) == HEf_SVKEY) {
269 char *k;
270 Newx(k, HEK_BASESIZE + sizeof(const SV *), char);
271 HeKEY_hek(ret) = (HEK*)k;
272 HeKEY_sv(ret) = sv_dup_inc(HeKEY_sv(e), param);
273 }
274 else if (!(HeKFLAGS(e) & HVhek_NOTSHARED)) {
275 /* This is hek_dup inlined, which seems to be important for speed
276 reasons. */
277 HEK * const source = HeKEY_hek(e);
278 HEK *shared = (HEK*)ptr_table_fetch(PL_ptr_table, source);
279
280 if (shared) {
281 /* We already shared this hash key. */
282 (void)share_hek_hek(shared);
283 }
284 else {
285 shared
286 = share_hek_flags(HEK_KEY(source), HEK_LEN(source),
287 HEK_HASH(source), HEK_FLAGS(source));
288 ptr_table_store(PL_ptr_table, source, shared);
289 }
290 HeKEY_hek(ret) = shared;
291 }
292 else
293 HeKEY_hek(ret) = save_hek_flags(HeKEY(e), HeKLEN(e), HeHASH(e),
294 HeKFLAGS(e));
295 HeVAL(ret) = sv_dup_inc(HeVAL(e), param);
296
297 HeNEXT(ret) = he_dup(HeNEXT(e), FALSE, param);
298 return ret;
299 }
300 #endif /* USE_ITHREADS */
301
302 static void
S_hv_notallowed(pTHX_ int flags,const char * key,I32 klen,const char * msg)303 S_hv_notallowed(pTHX_ int flags, const char *key, I32 klen,
304 const char *msg)
305 {
306 /* Straight to SVt_PVN here, as needed by sv_setpvn_fresh and
307 * sv_usepvn would otherwise call it */
308 SV * const sv = newSV_type_mortal(SVt_PV);
309
310 PERL_ARGS_ASSERT_HV_NOTALLOWED;
311
312 if (!(flags & HVhek_FREEKEY)) {
313 sv_setpvn_fresh(sv, key, klen);
314 }
315 else {
316 /* Need to free saved eventually assign to mortal SV */
317 /* XXX is this line an error ???: SV *sv = sv_newmortal(); */
318 sv_usepvn(sv, (char *) key, klen);
319 }
320 if (flags & HVhek_UTF8) {
321 SvUTF8_on(sv);
322 }
323 Perl_croak(aTHX_ msg, SVfARG(sv));
324 }
325
326 /* (klen == HEf_SVKEY) is special for MAGICAL hv entries, meaning key slot
327 * contains an SV* */
328
329 /*
330 =for apidoc hv_store
331 =for apidoc_item hv_stores
332
333 These each store SV C<val> with the specified key in hash C<hv>, returning NULL
334 if the operation failed or if the value did not need to be actually stored
335 within the hash (as in the case of tied hashes). Otherwise it can be
336 dereferenced to get the original C<SV*>.
337
338 They differ only in how the hash key is specified.
339
340 In C<hv_stores>, the key is a C language string literal, enclosed in double
341 quotes. It is never treated as being in UTF-8.
342
343 In C<hv_store>, C<key> is either NULL or points to the first byte of the string
344 specifying the key, and its length in bytes is given by the absolute value of
345 an additional parameter, C<klen>. A NULL key indicates the key is to be
346 treated as C<undef>, and C<klen> is ignored; otherwise the key string may
347 contain embedded-NUL bytes. If C<klen> is negative, the string is treated as
348 being encoded in UTF-8; otherwise not.
349
350 C<hv_store> has another extra parameter, C<hash>, a precomputed hash of the key
351 string, or zero if it has not been precomputed. This parameter is omitted from
352 C<hv_stores>, as it is computed automatically at compile time.
353
354 If <hv> is NULL, NULL is returned and no action is taken.
355
356 If C<val> is NULL, it is treated as being C<undef>; otherwise the caller is
357 responsible for suitably incrementing the reference count of C<val> before
358 the call, and decrementing it if the function returned C<NULL>. Effectively
359 a successful C<hv_store> takes ownership of one reference to C<val>. This is
360 usually what you want; a newly created SV has a reference count of one, so
361 if all your code does is create SVs then store them in a hash, C<hv_store>
362 will own the only reference to the new SV, and your code doesn't need to do
363 anything further to tidy up.
364
365 C<hv_store> is not implemented as a call to L</C<hv_store_ent>>, and does not
366 create a temporary SV for the key, so if your key data is not already in SV
367 form then use C<hv_store> in preference to C<hv_store_ent>.
368
369 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
370 information on how to use this function on tied hashes.
371
372 =for apidoc hv_store_ent
373
374 Stores C<val> in a hash. The hash key is specified as C<key>. The C<hash>
375 parameter is the precomputed hash value; if it is zero then Perl will
376 compute it. The return value is the new hash entry so created. It will be
377 C<NULL> if the operation failed or if the value did not need to be actually
378 stored within the hash (as in the case of tied hashes). Otherwise the
379 contents of the return value can be accessed using the C<He?> macros
380 described here. Note that the caller is responsible for suitably
381 incrementing the reference count of C<val> before the call, and
382 decrementing it if the function returned NULL. Effectively a successful
383 C<hv_store_ent> takes ownership of one reference to C<val>. This is
384 usually what you want; a newly created SV has a reference count of one, so
385 if all your code does is create SVs then store them in a hash, C<hv_store>
386 will own the only reference to the new SV, and your code doesn't need to do
387 anything further to tidy up. Note that C<hv_store_ent> only reads the C<key>;
388 unlike C<val> it does not take ownership of it, so maintaining the correct
389 reference count on C<key> is entirely the caller's responsibility. The reason
390 it does not take ownership, is that C<key> is not used after this function
391 returns, and so can be freed immediately. C<hv_store>
392 is not implemented as a call to C<hv_store_ent>, and does not create a temporary
393 SV for the key, so if your key data is not already in SV form then use
394 C<hv_store> in preference to C<hv_store_ent>.
395
396 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
397 information on how to use this function on tied hashes.
398
399 =for apidoc hv_exists
400
401 Returns a boolean indicating whether the specified hash key exists. The
402 absolute value of C<klen> is the length of the key. If C<klen> is
403 negative the key is assumed to be in UTF-8-encoded Unicode.
404
405 =for apidoc hv_fetch
406
407 Returns the SV which corresponds to the specified key in the hash.
408 The absolute value of C<klen> is the length of the key. If C<klen> is
409 negative the key is assumed to be in UTF-8-encoded Unicode. If
410 C<lval> is set then the fetch will be part of a store. This means that if
411 there is no value in the hash associated with the given key, then one is
412 created and a pointer to it is returned. The C<SV*> it points to can be
413 assigned to. But always check that the
414 return value is non-null before dereferencing it to an C<SV*>.
415
416 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
417 information on how to use this function on tied hashes.
418
419 =for apidoc hv_exists_ent
420
421 Returns a boolean indicating whether
422 the specified hash key exists. C<hash>
423 can be a valid precomputed hash value, or 0 to ask for it to be
424 computed.
425
426 =cut
427 */
428
429 /* returns an HE * structure with the all fields set */
430 /* note that hent_val will be a mortal sv for MAGICAL hashes */
431 /*
432 =for apidoc hv_fetch_ent
433
434 Returns the hash entry which corresponds to the specified key in the hash.
435 C<hash> must be a valid precomputed hash number for the given C<key>, or 0
436 if you want the function to compute it. IF C<lval> is set then the fetch
437 will be part of a store. Make sure the return value is non-null before
438 accessing it. The return value when C<hv> is a tied hash is a pointer to a
439 static location, so be sure to make a copy of the structure if you need to
440 store it somewhere.
441
442 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
443 information on how to use this function on tied hashes.
444
445 =cut
446 */
447
448 /* Common code for hv_delete()/hv_exists()/hv_fetch()/hv_store() */
449 void *
Perl_hv_common_key_len(pTHX_ HV * hv,const char * key,I32 klen_i32,const int action,SV * val,const U32 hash)450 Perl_hv_common_key_len(pTHX_ HV *hv, const char *key, I32 klen_i32,
451 const int action, SV *val, const U32 hash)
452 {
453 STRLEN klen;
454 int flags;
455
456 PERL_ARGS_ASSERT_HV_COMMON_KEY_LEN;
457
458 if (klen_i32 < 0) {
459 klen = -klen_i32;
460 flags = HVhek_UTF8;
461 } else {
462 klen = klen_i32;
463 flags = 0;
464 }
465 return hv_common(hv, NULL, key, klen, flags, action, val, hash);
466 }
467
468 void *
Perl_hv_common(pTHX_ HV * hv,SV * keysv,const char * key,STRLEN klen,int flags,int action,SV * val,U32 hash)469 Perl_hv_common(pTHX_ HV *hv, SV *keysv, const char *key, STRLEN klen,
470 int flags, int action, SV *val, U32 hash)
471 {
472 XPVHV* xhv;
473 HE *entry;
474 HE **oentry;
475 SV *sv;
476 bool is_utf8;
477 bool in_collision;
478 const int return_svp = action & HV_FETCH_JUST_SV;
479 HEK *keysv_hek = NULL;
480
481 if (!hv)
482 return NULL;
483 if (SvIS_FREED(hv))
484 return NULL;
485
486 assert(SvTYPE(hv) == SVt_PVHV);
487
488 if (SvSMAGICAL(hv) && SvGMAGICAL(hv) && !(action & HV_DISABLE_UVAR_XKEY)) {
489 MAGIC* mg;
490 if ((mg = mg_find((const SV *)hv, PERL_MAGIC_uvar))) {
491 struct ufuncs * const uf = (struct ufuncs *)mg->mg_ptr;
492 if (uf->uf_set == NULL) {
493 SV* obj = mg->mg_obj;
494
495 if (!keysv) {
496 keysv = newSVpvn_flags(key, klen, SVs_TEMP |
497 ((flags & HVhek_UTF8)
498 ? SVf_UTF8 : 0));
499 }
500
501 mg->mg_obj = keysv; /* pass key */
502 uf->uf_index = action; /* pass action */
503 magic_getuvar(MUTABLE_SV(hv), mg);
504 keysv = mg->mg_obj; /* may have changed */
505 mg->mg_obj = obj;
506
507 /* If the key may have changed, then we need to invalidate
508 any passed-in computed hash value. */
509 hash = 0;
510 }
511 }
512 }
513
514 /* flags might have HVhek_NOTSHARED set. If so, we need to ignore that.
515 Some callers to hv_common() pass the flags value from an existing HEK,
516 and if that HEK is not shared, then it has the relevant flag bit set,
517 which must not be passed into share_hek_flags().
518
519 It would be "purer" to insist that all callers clear it, but we'll end up
520 with subtle bugs if we leave it to them, or runtime assertion failures if
521 we try to enforce our documentation with landmines.
522
523 If keysv is true, all code paths assign a new value to flags with that
524 bit clear, so we're always "good". Hence we only need to explicitly clear
525 this bit in the else block. */
526 if (keysv) {
527 if (flags & HVhek_FREEKEY)
528 Safefree(key);
529 key = SvPV_const(keysv, klen);
530 is_utf8 = (SvUTF8(keysv) != 0);
531 if (SvIsCOW_shared_hash(keysv)) {
532 flags = HVhek_KEYCANONICAL | (is_utf8 ? HVhek_UTF8 : 0);
533 } else {
534 flags = 0;
535 }
536 } else {
537 is_utf8 = cBOOL(flags & HVhek_UTF8);
538 flags &= ~HVhek_NOTSHARED;
539 }
540
541 if (action & HV_DELETE) {
542 return (void *) hv_delete_common(hv, keysv, key, klen,
543 flags | (is_utf8 ? HVhek_UTF8 : 0),
544 action, hash);
545 }
546
547 xhv = (XPVHV*)SvANY(hv);
548 if (SvMAGICAL(hv)) {
549 if (SvRMAGICAL(hv) && !(action & (HV_FETCH_ISSTORE|HV_FETCH_ISEXISTS))) {
550 if (mg_find((const SV *)hv, PERL_MAGIC_tied)
551 || SvGMAGICAL((const SV *)hv))
552 {
553 /* FIXME should be able to skimp on the HE/HEK here when
554 HV_FETCH_JUST_SV is true. */
555 if (!keysv) {
556 keysv = newSVpvn_utf8(key, klen, is_utf8);
557 } else {
558 keysv = newSVsv(keysv);
559 }
560 sv = sv_newmortal();
561 mg_copy(MUTABLE_SV(hv), sv, (char *)keysv, HEf_SVKEY);
562
563 /* grab a fake HE/HEK pair from the pool or make a new one */
564 entry = PL_hv_fetch_ent_mh;
565 if (entry)
566 PL_hv_fetch_ent_mh = HeNEXT(entry);
567 else {
568 char *k;
569 entry = new_HE();
570 Newx(k, HEK_BASESIZE + sizeof(const SV *), char);
571 HeKEY_hek(entry) = (HEK*)k;
572 }
573 HeNEXT(entry) = NULL;
574 HeSVKEY_set(entry, keysv);
575 HeVAL(entry) = sv;
576 sv_upgrade(sv, SVt_PVLV);
577 LvTYPE(sv) = 'T';
578 /* so we can free entry when freeing sv */
579 LvTARG(sv) = MUTABLE_SV(entry);
580
581 /* XXX remove at some point? */
582 if (flags & HVhek_FREEKEY)
583 Safefree(key);
584
585 if (return_svp) {
586 return entry ? (void *) &HeVAL(entry) : NULL;
587 }
588 return (void *) entry;
589 }
590 #ifdef ENV_IS_CASELESS
591 else if (mg_find((const SV *)hv, PERL_MAGIC_env)) {
592 U32 i;
593 for (i = 0; i < klen; ++i)
594 if (isLOWER(key[i])) {
595 /* Would be nice if we had a routine to do the
596 copy and uppercase in a single pass through. */
597 const char * const nkey = strupr(savepvn(key,klen));
598 /* Note that this fetch is for nkey (the uppercased
599 key) whereas the store is for key (the original) */
600 void *result = hv_common(hv, NULL, nkey, klen,
601 HVhek_FREEKEY, /* free nkey */
602 0 /* non-LVAL fetch */
603 | HV_DISABLE_UVAR_XKEY
604 | return_svp,
605 NULL /* no value */,
606 0 /* compute hash */);
607 if (!result && (action & HV_FETCH_LVALUE)) {
608 /* This call will free key if necessary.
609 Do it this way to encourage compiler to tail
610 call optimise. */
611 result = hv_common(hv, keysv, key, klen, flags,
612 HV_FETCH_ISSTORE
613 | HV_DISABLE_UVAR_XKEY
614 | return_svp,
615 newSV_type(SVt_NULL), hash);
616 } else {
617 if (flags & HVhek_FREEKEY)
618 Safefree(key);
619 }
620 return result;
621 }
622 }
623 #endif
624 } /* ISFETCH */
625 else if (SvRMAGICAL(hv) && (action & HV_FETCH_ISEXISTS)) {
626 if (mg_find((const SV *)hv, PERL_MAGIC_tied)
627 || SvGMAGICAL((const SV *)hv)) {
628 /* I don't understand why hv_exists_ent has svret and sv,
629 whereas hv_exists only had one. */
630 SV * const svret = sv_newmortal();
631 sv = sv_newmortal();
632
633 if (keysv || is_utf8) {
634 if (!keysv) {
635 keysv = newSVpvn_utf8(key, klen, TRUE);
636 } else {
637 keysv = newSVsv(keysv);
638 }
639 mg_copy(MUTABLE_SV(hv), sv, (char *)sv_2mortal(keysv), HEf_SVKEY);
640 } else {
641 mg_copy(MUTABLE_SV(hv), sv, key, klen);
642 }
643 if (flags & HVhek_FREEKEY)
644 Safefree(key);
645 {
646 MAGIC * const mg = mg_find(sv, PERL_MAGIC_tiedelem);
647 if (mg)
648 magic_existspack(svret, mg);
649 }
650 /* This cast somewhat evil, but I'm merely using NULL/
651 not NULL to return the boolean exists.
652 And I know hv is not NULL. */
653 return SvTRUE_NN(svret) ? (void *)hv : NULL;
654 }
655 #ifdef ENV_IS_CASELESS
656 else if (mg_find((const SV *)hv, PERL_MAGIC_env)) {
657 /* XXX This code isn't UTF8 clean. */
658 char * const keysave = (char * const)key;
659 /* Will need to free this, so set FREEKEY flag. */
660 key = savepvn(key,klen);
661 key = (const char*)strupr((char*)key);
662 is_utf8 = FALSE;
663 hash = 0;
664 keysv = 0;
665
666 if (flags & HVhek_FREEKEY) {
667 Safefree(keysave);
668 }
669 flags |= HVhek_FREEKEY;
670 }
671 #endif
672 } /* ISEXISTS */
673 else if (action & HV_FETCH_ISSTORE) {
674 bool needs_copy;
675 bool needs_store;
676 hv_magic_check (hv, &needs_copy, &needs_store);
677 if (needs_copy) {
678 const bool save_taint = TAINT_get;
679 if (keysv || is_utf8) {
680 if (!keysv) {
681 keysv = newSVpvn_utf8(key, klen, TRUE);
682 }
683 if (TAINTING_get)
684 TAINT_set(SvTAINTED(keysv));
685 keysv = sv_2mortal(newSVsv(keysv));
686 mg_copy(MUTABLE_SV(hv), val, (char*)keysv, HEf_SVKEY);
687 } else {
688 mg_copy(MUTABLE_SV(hv), val, key, klen);
689 }
690
691 TAINT_IF(save_taint);
692 #ifdef NO_TAINT_SUPPORT
693 PERL_UNUSED_VAR(save_taint);
694 #endif
695 if (!needs_store) {
696 if (flags & HVhek_FREEKEY)
697 Safefree(key);
698 return NULL;
699 }
700 #ifdef ENV_IS_CASELESS
701 else if (mg_find((const SV *)hv, PERL_MAGIC_env)) {
702 /* XXX This code isn't UTF8 clean. */
703 const char *keysave = key;
704 /* Will need to free this, so set FREEKEY flag. */
705 key = savepvn(key,klen);
706 key = (const char*)strupr((char*)key);
707 is_utf8 = FALSE;
708 hash = 0;
709 keysv = 0;
710
711 if (flags & HVhek_FREEKEY) {
712 Safefree(keysave);
713 }
714 flags |= HVhek_FREEKEY;
715 }
716 #endif
717 }
718 } /* ISSTORE */
719 } /* SvMAGICAL */
720
721 if (!HvARRAY(hv)) {
722 if ((action & (HV_FETCH_LVALUE | HV_FETCH_ISSTORE))
723 #ifdef DYNAMIC_ENV_FETCH /* if it's an %ENV lookup, we may get it on the fly */
724 || (SvRMAGICAL((const SV *)hv)
725 && mg_find((const SV *)hv, PERL_MAGIC_env))
726 #endif
727 ) {
728 char *array;
729 Newxz(array,
730 PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */),
731 char);
732 HvARRAY(hv) = (HE**)array;
733 }
734 #ifdef DYNAMIC_ENV_FETCH
735 else if (action & HV_FETCH_ISEXISTS) {
736 /* for an %ENV exists, if we do an insert it's by a recursive
737 store call, so avoid creating HvARRAY(hv) right now. */
738 }
739 #endif
740 else {
741 /* XXX remove at some point? */
742 if (flags & HVhek_FREEKEY)
743 Safefree(key);
744
745 return NULL;
746 }
747 }
748
749 if (is_utf8 && !(flags & HVhek_KEYCANONICAL)) {
750 char * const keysave = (char *)key;
751 key = (char*)bytes_from_utf8((U8*)key, &klen, &is_utf8);
752 if (is_utf8)
753 flags |= HVhek_UTF8;
754 else
755 flags &= ~HVhek_UTF8;
756 if (key != keysave) {
757 if (flags & HVhek_FREEKEY)
758 Safefree(keysave);
759 flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
760 /* If the caller calculated a hash, it was on the sequence of
761 octets that are the UTF-8 form. We've now changed the sequence
762 of octets stored to that of the equivalent byte representation,
763 so the hash we need is different. */
764 hash = 0;
765 }
766 }
767
768 if (keysv && (SvIsCOW_shared_hash(keysv))) {
769 if (HvSHAREKEYS(hv))
770 keysv_hek = SvSHARED_HEK_FROM_PV(SvPVX_const(keysv));
771 hash = SvSHARED_HASH(keysv);
772 }
773 else if (!hash)
774 PERL_HASH(hash, key, klen);
775
776 #ifdef DYNAMIC_ENV_FETCH
777 if (!HvARRAY(hv)) entry = NULL;
778 else
779 #endif
780 {
781 entry = (HvARRAY(hv))[hash & (I32) HvMAX(hv)];
782 }
783
784 if (!entry)
785 goto not_found;
786
787 if (keysv_hek) {
788 /* keysv is actually a HEK in disguise, so we can match just by
789 * comparing the HEK pointers in the HE chain. There is a slight
790 * caveat: on something like "\x80", which has both plain and utf8
791 * representations, perl's hashes do encoding-insensitive lookups,
792 * but preserve the encoding of the stored key. Thus a particular
793 * key could map to two different HEKs in PL_strtab. We only
794 * conclude 'not found' if all the flags are the same; otherwise
795 * we fall back to a full search (this should only happen in rare
796 * cases).
797 */
798 int keysv_flags = HEK_FLAGS(keysv_hek);
799 HE *orig_entry = entry;
800
801 for (; entry; entry = HeNEXT(entry)) {
802 HEK *hek = HeKEY_hek(entry);
803 if (hek == keysv_hek)
804 goto found;
805 if (HEK_FLAGS(hek) != keysv_flags)
806 break; /* need to do full match */
807 }
808 if (!entry)
809 goto not_found;
810 /* failed on shortcut - do full search loop */
811 entry = orig_entry;
812 }
813
814 for (; entry; entry = HeNEXT(entry)) {
815 if (HeHASH(entry) != hash) /* strings can't be equal */
816 continue;
817 if (HeKLEN(entry) != (I32)klen)
818 continue;
819 if (memNE(HeKEY(entry),key,klen)) /* is this it? */
820 continue;
821 if ((HeKFLAGS(entry) ^ flags) & HVhek_UTF8)
822 continue;
823
824 found:
825 if (action & (HV_FETCH_LVALUE|HV_FETCH_ISSTORE)) {
826 if ((HeKFLAGS(entry) ^ flags) & HVhek_WASUTF8) {
827 /* We match if HVhek_UTF8 bit in our flags and hash key's
828 match. But if entry was set previously with HVhek_WASUTF8
829 and key now doesn't (or vice versa) then we should change
830 the key's flag, as this is assignment. */
831 if ((HeKFLAGS(entry) & HVhek_NOTSHARED) == 0) {
832 /* Need to swap the key we have for a key with the flags we
833 need. As keys are shared we can't just write to the
834 flag, so we share the new one, unshare the old one. */
835 HEK * const new_hek
836 = share_hek_flags(key, klen, hash, flags & ~HVhek_FREEKEY);
837 unshare_hek (HeKEY_hek(entry));
838 HeKEY_hek(entry) = new_hek;
839 }
840 else if (hv == PL_strtab) {
841 /* PL_strtab is usually the only hash without HvSHAREKEYS,
842 so putting this test here is cheap */
843 if (flags & HVhek_FREEKEY)
844 Safefree(key);
845 Perl_croak(aTHX_ S_strtab_error,
846 action & HV_FETCH_LVALUE ? "fetch" : "store");
847 }
848 else {
849 /* Effectively this is save_hek_flags() for a new version
850 of the HEK and Safefree() of the old rolled together. */
851 HeKFLAGS(entry) ^= HVhek_WASUTF8;
852 }
853 if (flags & HVhek_ENABLEHVKFLAGS)
854 HvHASKFLAGS_on(hv);
855 }
856 if (HeVAL(entry) == &PL_sv_placeholder) {
857 /* yes, can store into placeholder slot */
858 if (action & HV_FETCH_LVALUE) {
859 if (SvMAGICAL(hv)) {
860 /* This preserves behaviour with the old hv_fetch
861 implementation which at this point would bail out
862 with a break; (at "if we find a placeholder, we
863 pretend we haven't found anything")
864
865 That break mean that if a placeholder were found, it
866 caused a call into hv_store, which in turn would
867 check magic, and if there is no magic end up pretty
868 much back at this point (in hv_store's code). */
869 break;
870 }
871 /* LVAL fetch which actually needs a store. */
872 val = newSV_type(SVt_NULL);
873 HvPLACEHOLDERS(hv)--;
874 } else {
875 /* store */
876 if (val != &PL_sv_placeholder)
877 HvPLACEHOLDERS(hv)--;
878 }
879 HeVAL(entry) = val;
880 } else if (action & HV_FETCH_ISSTORE) {
881 SvREFCNT_dec(HeVAL(entry));
882 HeVAL(entry) = val;
883 }
884 } else if (HeVAL(entry) == &PL_sv_placeholder) {
885 /* if we find a placeholder, we pretend we haven't found
886 anything */
887 break;
888 }
889 if (flags & HVhek_FREEKEY)
890 Safefree(key);
891 if (return_svp) {
892 return (void *) &HeVAL(entry);
893 }
894 return entry;
895 }
896
897 not_found:
898 #ifdef DYNAMIC_ENV_FETCH /* %ENV lookup? If so, try to fetch the value now */
899 if (!(action & HV_FETCH_ISSTORE)
900 && SvRMAGICAL((const SV *)hv)
901 && mg_find((const SV *)hv, PERL_MAGIC_env)) {
902 unsigned long len;
903 const char * const env = PerlEnv_ENVgetenv_len(key,&len);
904 if (env) {
905 sv = newSVpvn(env,len);
906 SvTAINTED_on(sv);
907 return hv_common(hv, keysv, key, klen, flags,
908 HV_FETCH_ISSTORE|HV_DISABLE_UVAR_XKEY|return_svp,
909 sv, hash);
910 }
911 }
912 #endif
913
914 if (!entry && SvREADONLY(hv) && !(action & HV_FETCH_ISEXISTS)) {
915 hv_notallowed(flags, key, klen,
916 "Attempt to access disallowed key '%" SVf "' in"
917 " a restricted hash");
918 }
919 if (!(action & (HV_FETCH_LVALUE|HV_FETCH_ISSTORE))) {
920 /* Not doing some form of store, so return failure. */
921 if (flags & HVhek_FREEKEY)
922 Safefree(key);
923 return NULL;
924 }
925 if (action & HV_FETCH_LVALUE) {
926 val = action & HV_FETCH_EMPTY_HE ? NULL : newSV_type(SVt_NULL);
927 if (SvMAGICAL(hv)) {
928 /* At this point the old hv_fetch code would call to hv_store,
929 which in turn might do some tied magic. So we need to make that
930 magic check happen. */
931 /* gonna assign to this, so it better be there */
932 /* If a fetch-as-store fails on the fetch, then the action is to
933 recurse once into "hv_store". If we didn't do this, then that
934 recursive call would call the key conversion routine again.
935 However, as we replace the original key with the converted
936 key, this would result in a double conversion, which would show
937 up as a bug if the conversion routine is not idempotent.
938 Hence the use of HV_DISABLE_UVAR_XKEY. */
939 return hv_common(hv, keysv, key, klen, flags,
940 HV_FETCH_ISSTORE|HV_DISABLE_UVAR_XKEY|return_svp,
941 val, hash);
942 /* XXX Surely that could leak if the fetch-was-store fails?
943 Just like the hv_fetch. */
944 }
945 }
946
947 /* Welcome to hv_store... */
948
949 if (!HvARRAY(hv)) {
950 /* Not sure if we can get here. I think the only case of oentry being
951 NULL is for %ENV with dynamic env fetch. But that should disappear
952 with magic in the previous code. */
953 char *array;
954 Newxz(array,
955 PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */),
956 char);
957 HvARRAY(hv) = (HE**)array;
958 }
959
960 oentry = &(HvARRAY(hv))[hash & (I32) xhv->xhv_max];
961
962 /* share_hek_flags will do the free for us. This might be considered
963 bad API design. */
964 if (LIKELY(HvSHAREKEYS(hv))) {
965 entry = new_HE();
966 HeKEY_hek(entry) = share_hek_flags(key, klen, hash, flags);
967 }
968 else if (UNLIKELY(hv == PL_strtab)) {
969 /* PL_strtab is usually the only hash without HvSHAREKEYS, so putting
970 this test here is cheap */
971 if (flags & HVhek_FREEKEY)
972 Safefree(key);
973 Perl_croak(aTHX_ S_strtab_error,
974 action & HV_FETCH_LVALUE ? "fetch" : "store");
975 }
976 else {
977 /* gotta do the real thing */
978 entry = new_HE();
979 HeKEY_hek(entry) = save_hek_flags(key, klen, hash, flags);
980 }
981 HeVAL(entry) = val;
982 in_collision = cBOOL(*oentry != NULL);
983
984
985 #ifdef PERL_HASH_RANDOMIZE_KEYS
986 /* This logic semi-randomizes the insert order in a bucket.
987 * Either we insert into the top, or the slot below the top,
988 * making it harder to see if there is a collision. We also
989 * reset the iterator randomizer if there is one.
990 */
991
992
993 if ( *oentry && PL_HASH_RAND_BITS_ENABLED) {
994 UPDATE_HASH_RAND_BITS_KEY(key,klen);
995 if ( PL_hash_rand_bits & 1 ) {
996 HeNEXT(entry) = HeNEXT(*oentry);
997 HeNEXT(*oentry) = entry;
998 } else {
999 HeNEXT(entry) = *oentry;
1000 *oentry = entry;
1001 }
1002 } else
1003 #endif
1004 {
1005 HeNEXT(entry) = *oentry;
1006 *oentry = entry;
1007 }
1008 #ifdef PERL_HASH_RANDOMIZE_KEYS
1009 if (HvHasAUX(hv)) {
1010 /* Currently this makes various tests warn in annoying ways.
1011 * So Silenced for now. - Yves | bogus end of comment =>* /
1012 if (HvAUX(hv)->xhv_riter != -1) {
1013 Perl_ck_warner_d(aTHX_ packWARN(WARN_INTERNAL),
1014 "[TESTING] Inserting into a hash during each() traversal results in undefined behavior"
1015 pTHX__FORMAT
1016 pTHX__VALUE);
1017 }
1018 */
1019 MAYBE_UPDATE_HASH_RAND_BITS_KEY(key,klen);
1020 HvAUX(hv)->xhv_rand= (U32)PL_hash_rand_bits;
1021 }
1022 #endif
1023
1024 if (val == &PL_sv_placeholder)
1025 HvPLACEHOLDERS(hv)++;
1026 if (flags & HVhek_ENABLEHVKFLAGS)
1027 HvHASKFLAGS_on(hv);
1028
1029 xhv->xhv_keys++; /* HvTOTALKEYS(hv)++ */
1030 if ( in_collision && DO_HSPLIT(xhv) ) {
1031 const STRLEN oldsize = xhv->xhv_max + 1;
1032 const U32 items = (U32)HvPLACEHOLDERS_get(hv);
1033
1034 if (items /* hash has placeholders */
1035 && !SvREADONLY(hv) /* but is not a restricted hash */) {
1036 /* If this hash previously was a "restricted hash" and had
1037 placeholders, but the "restricted" flag has been turned off,
1038 then the placeholders no longer serve any useful purpose.
1039 However, they have the downsides of taking up RAM, and adding
1040 extra steps when finding used values. It's safe to clear them
1041 at this point, even though Storable rebuilds restricted hashes by
1042 putting in all the placeholders (first) before turning on the
1043 readonly flag, because Storable always pre-splits the hash.
1044 If we're lucky, then we may clear sufficient placeholders to
1045 avoid needing to split the hash at all. */
1046 clear_placeholders(hv, items);
1047 if (DO_HSPLIT(xhv))
1048 hsplit(hv, oldsize, oldsize * 2);
1049 } else
1050 hsplit(hv, oldsize, oldsize * 2);
1051 }
1052
1053 if (return_svp) {
1054 return entry ? (void *) &HeVAL(entry) : NULL;
1055 }
1056 return (void *) entry;
1057 }
1058
1059 STATIC void
S_hv_magic_check(HV * hv,bool * needs_copy,bool * needs_store)1060 S_hv_magic_check(HV *hv, bool *needs_copy, bool *needs_store)
1061 {
1062 const MAGIC *mg = SvMAGIC(hv);
1063
1064 PERL_ARGS_ASSERT_HV_MAGIC_CHECK;
1065
1066 *needs_copy = FALSE;
1067 *needs_store = TRUE;
1068 while (mg) {
1069 if (isUPPER(mg->mg_type)) {
1070 *needs_copy = TRUE;
1071 if (mg->mg_type == PERL_MAGIC_tied) {
1072 *needs_store = FALSE;
1073 return; /* We've set all there is to set. */
1074 }
1075 }
1076 mg = mg->mg_moremagic;
1077 }
1078 }
1079
1080 /*
1081 =for apidoc hv_scalar
1082
1083 Evaluates the hash in scalar context and returns the result.
1084
1085 When the hash is tied dispatches through to the SCALAR method,
1086 otherwise returns a mortal SV containing the number of keys
1087 in the hash.
1088
1089 Note, prior to 5.25 this function returned what is now
1090 returned by the hv_bucket_ratio() function.
1091
1092 =cut
1093 */
1094
1095 SV *
Perl_hv_scalar(pTHX_ HV * hv)1096 Perl_hv_scalar(pTHX_ HV *hv)
1097 {
1098 SV *sv;
1099 UV u;
1100
1101 PERL_ARGS_ASSERT_HV_SCALAR;
1102
1103 if (SvRMAGICAL(hv)) {
1104 MAGIC * const mg = mg_find((const SV *)hv, PERL_MAGIC_tied);
1105 if (mg)
1106 return magic_scalarpack(hv, mg);
1107 }
1108
1109 sv = newSV_type_mortal(SVt_IV);
1110
1111 /* Inlined sv_setuv(sv, HvUSEDKEYS(hv)) follows:*/
1112 u = HvUSEDKEYS(hv);
1113
1114 if (u <= (UV)IV_MAX) {
1115 SvIV_set(sv, (IV)u);
1116 (void)SvIOK_only(sv);
1117 SvTAINT(sv);
1118 } else {
1119 SvIV_set(sv, 0);
1120 SvUV_set(sv, u);
1121 (void)SvIOK_only_UV(sv);
1122 SvTAINT(sv);
1123 }
1124
1125 return sv;
1126 }
1127
1128
1129 /*
1130 hv_pushkv(): push all the keys and/or values of a hash onto the stack.
1131 The rough Perl equivalents:
1132 () = %hash;
1133 () = keys %hash;
1134 () = values %hash;
1135
1136 Resets the hash's iterator.
1137
1138 flags : 1 = push keys
1139 2 = push values
1140 1|2 = push keys and values
1141 XXX use symbolic flag constants at some point?
1142 I might unroll the non-tied hv_iternext() in here at some point - DAPM
1143 */
1144
1145 void
Perl_hv_pushkv(pTHX_ HV * hv,U32 flags)1146 Perl_hv_pushkv(pTHX_ HV *hv, U32 flags)
1147 {
1148 HE *entry;
1149 bool tied = SvRMAGICAL(hv) && (mg_find(MUTABLE_SV(hv), PERL_MAGIC_tied)
1150 #ifdef DYNAMIC_ENV_FETCH /* might not know number of keys yet */
1151 || mg_find(MUTABLE_SV(hv), PERL_MAGIC_env)
1152 #endif
1153 );
1154 dSP;
1155
1156 PERL_ARGS_ASSERT_HV_PUSHKV;
1157 assert(flags); /* must be pushing at least one of keys and values */
1158
1159 (void)hv_iterinit(hv);
1160
1161 if (tied) {
1162 SSize_t ext = (flags == 3) ? 2 : 1;
1163 while ((entry = hv_iternext(hv))) {
1164 EXTEND(SP, ext);
1165 if (flags & 1)
1166 PUSHs(hv_iterkeysv(entry));
1167 if (flags & 2)
1168 PUSHs(hv_iterval(hv, entry));
1169 }
1170 }
1171 else {
1172 Size_t nkeys = HvUSEDKEYS(hv);
1173 SSize_t ext;
1174
1175 if (!nkeys)
1176 return;
1177
1178 /* 2*nkeys() should never be big enough to truncate or wrap */
1179 assert(nkeys <= (SSize_t_MAX >> 1));
1180 ext = nkeys * ((flags == 3) ? 2 : 1);
1181
1182 EXTEND_MORTAL(nkeys);
1183 EXTEND(SP, ext);
1184
1185 while ((entry = hv_iternext(hv))) {
1186 if (flags & 1) {
1187 SV *keysv = newSVhek(HeKEY_hek(entry));
1188 SvTEMP_on(keysv);
1189 PL_tmps_stack[++PL_tmps_ix] = keysv;
1190 PUSHs(keysv);
1191 }
1192 if (flags & 2)
1193 PUSHs(HeVAL(entry));
1194 }
1195 }
1196
1197 PUTBACK;
1198 }
1199
1200
1201 /*
1202 =for apidoc hv_bucket_ratio
1203
1204 If the hash is tied dispatches through to the SCALAR tied method,
1205 otherwise if the hash contains no keys returns 0, otherwise returns
1206 a mortal sv containing a string specifying the number of used buckets,
1207 followed by a slash, followed by the number of available buckets.
1208
1209 This function is expensive, it must scan all of the buckets
1210 to determine which are used, and the count is NOT cached.
1211 In a large hash this could be a lot of buckets.
1212
1213 =cut
1214 */
1215
1216 SV *
Perl_hv_bucket_ratio(pTHX_ HV * hv)1217 Perl_hv_bucket_ratio(pTHX_ HV *hv)
1218 {
1219 SV *sv;
1220
1221 PERL_ARGS_ASSERT_HV_BUCKET_RATIO;
1222
1223 if (SvRMAGICAL(hv)) {
1224 MAGIC * const mg = mg_find((const SV *)hv, PERL_MAGIC_tied);
1225 if (mg)
1226 return magic_scalarpack(hv, mg);
1227 }
1228
1229 if (HvUSEDKEYS((HV *)hv)) {
1230 sv = sv_newmortal();
1231 Perl_sv_setpvf(aTHX_ sv, "%ld/%ld",
1232 (long)HvFILL(hv), (long)HvMAX(hv) + 1);
1233 }
1234 else
1235 sv = &PL_sv_zero;
1236
1237 return sv;
1238 }
1239
1240 /*
1241 =for apidoc hv_delete
1242
1243 Deletes a key/value pair in the hash. The value's SV is removed from
1244 the hash, made mortal, and returned to the caller. The absolute
1245 value of C<klen> is the length of the key. If C<klen> is negative the
1246 key is assumed to be in UTF-8-encoded Unicode. The C<flags> value
1247 will normally be zero; if set to C<G_DISCARD> then C<NULL> will be returned.
1248 C<NULL> will also be returned if the key is not found.
1249
1250 =for apidoc hv_delete_ent
1251
1252 Deletes a key/value pair in the hash. The value SV is removed from the hash,
1253 made mortal, and returned to the caller. The C<flags> value will normally be
1254 zero; if set to C<G_DISCARD> then C<NULL> will be returned. C<NULL> will also
1255 be returned if the key is not found. C<hash> can be a valid precomputed hash
1256 value, or 0 to ask for it to be computed.
1257
1258 =cut
1259 */
1260
1261 STATIC SV *
S_hv_delete_common(pTHX_ HV * hv,SV * keysv,const char * key,STRLEN klen,int k_flags,I32 d_flags,U32 hash)1262 S_hv_delete_common(pTHX_ HV *hv, SV *keysv, const char *key, STRLEN klen,
1263 int k_flags, I32 d_flags, U32 hash)
1264 {
1265 XPVHV* xhv;
1266 HE *entry;
1267 HE **oentry;
1268 HE **first_entry;
1269 bool is_utf8 = cBOOL(k_flags & HVhek_UTF8);
1270 HEK *keysv_hek = NULL;
1271 U8 mro_changes = 0; /* 1 = isa; 2 = package moved */
1272 SV *sv;
1273 GV *gv = NULL;
1274 HV *stash = NULL;
1275
1276 if (SvMAGICAL(hv)) {
1277 bool needs_copy;
1278 bool needs_store;
1279 hv_magic_check (hv, &needs_copy, &needs_store);
1280
1281 if (needs_copy) {
1282 SV *sv;
1283 entry = (HE *) hv_common(hv, keysv, key, klen,
1284 k_flags & ~HVhek_FREEKEY,
1285 HV_FETCH_LVALUE|HV_DISABLE_UVAR_XKEY,
1286 NULL, hash);
1287 sv = entry ? HeVAL(entry) : NULL;
1288 if (sv) {
1289 if (SvMAGICAL(sv)) {
1290 mg_clear(sv);
1291 }
1292 if (!needs_store) {
1293 if (mg_find(sv, PERL_MAGIC_tiedelem)) {
1294 /* No longer an element */
1295 sv_unmagic(sv, PERL_MAGIC_tiedelem);
1296 return sv;
1297 }
1298 return NULL; /* element cannot be deleted */
1299 }
1300 #ifdef ENV_IS_CASELESS
1301 else if (mg_find((const SV *)hv, PERL_MAGIC_env)) {
1302 /* XXX This code isn't UTF8 clean. */
1303 keysv = newSVpvn_flags(key, klen, SVs_TEMP);
1304 if (k_flags & HVhek_FREEKEY) {
1305 Safefree(key);
1306 }
1307 key = strupr(SvPVX(keysv));
1308 is_utf8 = 0;
1309 k_flags = 0;
1310 hash = 0;
1311 }
1312 #endif
1313 }
1314 }
1315 }
1316 xhv = (XPVHV*)SvANY(hv);
1317 if (!HvTOTALKEYS(hv))
1318 return NULL;
1319
1320 if (is_utf8 && !(k_flags & HVhek_KEYCANONICAL)) {
1321 const char * const keysave = key;
1322 key = (char*)bytes_from_utf8((U8*)key, &klen, &is_utf8);
1323
1324 if (is_utf8)
1325 k_flags |= HVhek_UTF8;
1326 else
1327 k_flags &= ~HVhek_UTF8;
1328 if (key != keysave) {
1329 if (k_flags & HVhek_FREEKEY) {
1330 /* This shouldn't happen if our caller does what we expect,
1331 but strictly the API allows it. */
1332 Safefree(keysave);
1333 }
1334 k_flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
1335 }
1336 }
1337
1338 if (keysv && (SvIsCOW_shared_hash(keysv))) {
1339 if (HvSHAREKEYS(hv))
1340 keysv_hek = SvSHARED_HEK_FROM_PV(SvPVX_const(keysv));
1341 hash = SvSHARED_HASH(keysv);
1342 }
1343 else if (!hash)
1344 PERL_HASH(hash, key, klen);
1345
1346 first_entry = oentry = &(HvARRAY(hv))[hash & (I32) HvMAX(hv)];
1347 entry = *oentry;
1348
1349 if (!entry)
1350 goto not_found;
1351
1352 if (keysv_hek) {
1353 /* keysv is actually a HEK in disguise, so we can match just by
1354 * comparing the HEK pointers in the HE chain. There is a slight
1355 * caveat: on something like "\x80", which has both plain and utf8
1356 * representations, perl's hashes do encoding-insensitive lookups,
1357 * but preserve the encoding of the stored key. Thus a particular
1358 * key could map to two different HEKs in PL_strtab. We only
1359 * conclude 'not found' if all the flags are the same; otherwise
1360 * we fall back to a full search (this should only happen in rare
1361 * cases).
1362 */
1363 int keysv_flags = HEK_FLAGS(keysv_hek);
1364
1365 for (; entry; oentry = &HeNEXT(entry), entry = *oentry) {
1366 HEK *hek = HeKEY_hek(entry);
1367 if (hek == keysv_hek)
1368 goto found;
1369 if (HEK_FLAGS(hek) != keysv_flags)
1370 break; /* need to do full match */
1371 }
1372 if (!entry)
1373 goto not_found;
1374 /* failed on shortcut - do full search loop */
1375 oentry = first_entry;
1376 entry = *oentry;
1377 }
1378
1379 for (; entry; oentry = &HeNEXT(entry), entry = *oentry) {
1380 if (HeHASH(entry) != hash) /* strings can't be equal */
1381 continue;
1382 if (HeKLEN(entry) != (I32)klen)
1383 continue;
1384 if (memNE(HeKEY(entry),key,klen)) /* is this it? */
1385 continue;
1386 if ((HeKFLAGS(entry) ^ k_flags) & HVhek_UTF8)
1387 continue;
1388
1389 found:
1390 if (hv == PL_strtab) {
1391 if (k_flags & HVhek_FREEKEY)
1392 Safefree(key);
1393 Perl_croak(aTHX_ S_strtab_error, "delete");
1394 }
1395
1396 sv = HeVAL(entry);
1397
1398 /* if placeholder is here, it's already been deleted.... */
1399 if (sv == &PL_sv_placeholder) {
1400 if (k_flags & HVhek_FREEKEY)
1401 Safefree(key);
1402 return NULL;
1403 }
1404 if (SvREADONLY(hv) && sv && SvREADONLY(sv)) {
1405 hv_notallowed(k_flags, key, klen,
1406 "Attempt to delete readonly key '%" SVf "' from"
1407 " a restricted hash");
1408 }
1409
1410 /*
1411 * If a restricted hash, rather than really deleting the entry, put
1412 * a placeholder there. This marks the key as being "approved", so
1413 * we can still access via not-really-existing key without raising
1414 * an error.
1415 */
1416 if (SvREADONLY(hv)) {
1417 /* We'll be saving this slot, so the number of allocated keys
1418 * doesn't go down, but the number placeholders goes up */
1419 HeVAL(entry) = &PL_sv_placeholder;
1420 HvPLACEHOLDERS(hv)++;
1421 }
1422 else {
1423 HeVAL(entry) = NULL;
1424 *oentry = HeNEXT(entry);
1425 if (HvHasAUX(hv) && entry == HvAUX(hv)->xhv_eiter /* HvEITER(hv) */) {
1426 HvLAZYDEL_on(hv);
1427 }
1428 else {
1429 if (HvHasAUX(hv) && HvLAZYDEL(hv) &&
1430 entry == HeNEXT(HvAUX(hv)->xhv_eiter))
1431 HeNEXT(HvAUX(hv)->xhv_eiter) = HeNEXT(entry);
1432 hv_free_ent(NULL, entry);
1433 }
1434 xhv->xhv_keys--; /* HvTOTALKEYS(hv)-- */
1435 if (xhv->xhv_keys == 0)
1436 HvHASKFLAGS_off(hv);
1437 }
1438
1439 /* If this is a stash and the key ends with ::, then someone is
1440 * deleting a package.
1441 */
1442 if (sv && SvTYPE(sv) == SVt_PVGV && HvHasENAME(hv)) {
1443 gv = (GV *)sv;
1444 if ((
1445 (klen > 1 && key[klen-2] == ':' && key[klen-1] == ':')
1446 ||
1447 (klen == 1 && key[0] == ':')
1448 )
1449 && (klen != 6 || hv!=PL_defstash || memNE(key,"main::",6))
1450 && (stash = GvHV((GV *)gv))
1451 && HvHasENAME(stash)) {
1452 /* A previous version of this code checked that the
1453 * GV was still in the symbol table by fetching the
1454 * GV with its name. That is not necessary (and
1455 * sometimes incorrect), as HvENAME cannot be set
1456 * on hv if it is not in the symtab. */
1457 mro_changes = 2;
1458 /* Hang on to it for a bit. */
1459 SvREFCNT_inc_simple_void_NN(
1460 sv_2mortal((SV *)gv)
1461 );
1462 }
1463 else if (memEQs(key, klen, "ISA") && GvAV(gv)) {
1464 AV *isa = GvAV(gv);
1465 MAGIC *mg = mg_find((SV*)isa, PERL_MAGIC_isa);
1466
1467 mro_changes = 1;
1468 if (mg) {
1469 if (mg->mg_obj == (SV*)gv) {
1470 /* This is the only stash this ISA was used for.
1471 * The isaelem magic asserts if there's no
1472 * isa magic on the array, so explicitly
1473 * remove the magic on both the array and its
1474 * elements. @ISA shouldn't be /too/ large.
1475 */
1476 SV **svp, **end;
1477 strip_magic:
1478 svp = AvARRAY(isa);
1479 if (svp) {
1480 end = svp + (AvFILLp(isa)+1);
1481 while (svp < end) {
1482 if (*svp)
1483 mg_free_type(*svp, PERL_MAGIC_isaelem);
1484 ++svp;
1485 }
1486 }
1487 mg_free_type((SV*)GvAV(gv), PERL_MAGIC_isa);
1488 }
1489 else {
1490 /* mg_obj is an array of stashes
1491 Note that the array doesn't keep a reference
1492 count on the stashes.
1493 */
1494 AV *av = (AV*)mg->mg_obj;
1495 SV **svp, **arrayp;
1496 SSize_t index;
1497 SSize_t items;
1498
1499 assert(SvTYPE(mg->mg_obj) == SVt_PVAV);
1500
1501 /* remove the stash from the magic array */
1502 arrayp = svp = AvARRAY(av);
1503 items = AvFILLp(av) + 1;
1504 if (items == 1) {
1505 assert(*arrayp == (SV *)gv);
1506 mg->mg_obj = NULL;
1507 /* avoid a double free on the last stash */
1508 AvFILLp(av) = -1;
1509 /* The magic isn't MGf_REFCOUNTED, so release
1510 * the array manually.
1511 */
1512 SvREFCNT_dec_NN(av);
1513 goto strip_magic;
1514 }
1515 else {
1516 while (items--) {
1517 if (*svp == (SV*)gv)
1518 break;
1519 ++svp;
1520 }
1521 index = svp - arrayp;
1522 assert(index >= 0 && index <= AvFILLp(av));
1523 if (index < AvFILLp(av)) {
1524 arrayp[index] = arrayp[AvFILLp(av)];
1525 }
1526 arrayp[AvFILLp(av)] = NULL;
1527 --AvFILLp(av);
1528 }
1529 }
1530 }
1531 }
1532 }
1533
1534 if (k_flags & HVhek_FREEKEY)
1535 Safefree(key);
1536
1537 if (sv) {
1538 /* deletion of method from stash */
1539 if (isGV(sv) && isGV_with_GP(sv) && GvCVu(sv)
1540 && HvHasENAME(hv))
1541 mro_method_changed_in(hv);
1542
1543 if (d_flags & G_DISCARD) {
1544 SvREFCNT_dec(sv);
1545 sv = NULL;
1546 }
1547 else {
1548 sv_2mortal(sv);
1549 }
1550 }
1551
1552 if (mro_changes == 1) mro_isa_changed_in(hv);
1553 else if (mro_changes == 2)
1554 mro_package_moved(NULL, stash, gv, 1);
1555
1556 return sv;
1557 }
1558
1559 not_found:
1560 if (SvREADONLY(hv)) {
1561 hv_notallowed(k_flags, key, klen,
1562 "Attempt to delete disallowed key '%" SVf "' from"
1563 " a restricted hash");
1564 }
1565
1566 if (k_flags & HVhek_FREEKEY)
1567 Safefree(key);
1568 return NULL;
1569 }
1570
1571 /* HVs are used for (at least) three things
1572 1) objects
1573 2) symbol tables
1574 3) associative arrays
1575
1576 shared hash keys benefit the first two greatly, because keys are likely
1577 to be re-used between objects, or for constants in the optree
1578
1579 However, for large associative arrays (lookup tables, "seen" hashes) keys are
1580 unlikely to be re-used. Hence having those keys in the shared string table as
1581 well as the hash is a memory hit, if they are never actually shared with a
1582 second hash. Hence we turn off shared hash keys if a (regular) hash gets
1583 large.
1584
1585 This is a heuristic. There might be a better answer than 42, but for now
1586 we'll use it.
1587
1588 NOTE: Configure with -Accflags='-DPERL_USE_UNSHARED_KEYS_IN_LARGE_HASHES'
1589 to enable this new functionality.
1590 */
1591
1592 #ifdef PERL_USE_UNSHARED_KEYS_IN_LARGE_HASHES
1593 static bool
S_large_hash_heuristic(pTHX_ HV * hv,STRLEN size)1594 S_large_hash_heuristic(pTHX_ HV *hv, STRLEN size) {
1595 if (size > 42
1596 && !SvOBJECT(hv)
1597 && !(HvHasAUX(hv) && HvENAME_get(hv))) {
1598 /* This hash appears to be growing quite large.
1599 We gamble that it is not sharing keys with other hashes. */
1600 return TRUE;
1601 }
1602 return FALSE;
1603 }
1604 #endif
1605
1606 STATIC void
S_hsplit(pTHX_ HV * hv,STRLEN const oldsize,STRLEN newsize)1607 S_hsplit(pTHX_ HV *hv, STRLEN const oldsize, STRLEN newsize)
1608 {
1609 STRLEN i = 0;
1610 char *a = (char*) HvARRAY(hv);
1611 HE **aep;
1612
1613 PERL_ARGS_ASSERT_HSPLIT;
1614 if (newsize > MAX_BUCKET_MAX+1)
1615 return;
1616
1617 PL_nomemok = TRUE;
1618 Renew(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize), char);
1619 PL_nomemok = FALSE;
1620 if (!a) {
1621 return;
1622 }
1623
1624 #ifdef PERL_HASH_RANDOMIZE_KEYS
1625 /* the idea of this is that we create a "random" value by hashing the address of
1626 * the array, we then use the low bit to decide if we insert at the top, or insert
1627 * second from top. After each such insert we rotate the hashed value. So we can
1628 * use the same hashed value over and over, and in normal build environments use
1629 * very few ops to do so. ROTL32() should produce a single machine operation. */
1630 MAYBE_UPDATE_HASH_RAND_BITS();
1631 #endif
1632 HvARRAY(hv) = (HE**) a;
1633 HvMAX(hv) = newsize - 1;
1634 /* now we can safely clear the second half */
1635 Zero(&a[oldsize * sizeof(HE*)], (newsize-oldsize) * sizeof(HE*), char); /* zero 2nd half*/
1636
1637 if (!HvTOTALKEYS(hv)) /* skip rest if no entries */
1638 return;
1639
1640 /* don't share keys in large simple hashes */
1641 if (LARGE_HASH_HEURISTIC(hv, HvTOTALKEYS(hv)))
1642 HvSHAREKEYS_off(hv);
1643
1644
1645 newsize--;
1646 aep = (HE**)a;
1647 do {
1648 HE **oentry = aep + i;
1649 HE *entry = aep[i];
1650
1651 if (!entry) /* non-existent */
1652 continue;
1653 do {
1654 U32 j = (HeHASH(entry) & newsize);
1655 if (j != (U32)i) {
1656 *oentry = HeNEXT(entry);
1657 #ifdef PERL_HASH_RANDOMIZE_KEYS
1658 /* if the target cell is empty or PL_HASH_RAND_BITS_ENABLED is false
1659 * insert to top, otherwise rotate the bucket rand 1 bit,
1660 * and use the new low bit to decide if we insert at top,
1661 * or next from top. IOW, we only rotate on a collision.*/
1662 if (aep[j] && PL_HASH_RAND_BITS_ENABLED) {
1663 UPDATE_HASH_RAND_BITS();
1664 if (PL_hash_rand_bits & 1) {
1665 HeNEXT(entry)= HeNEXT(aep[j]);
1666 HeNEXT(aep[j])= entry;
1667 } else {
1668 /* Note, this is structured in such a way as the optimizer
1669 * should eliminate the duplicated code here and below without
1670 * us needing to explicitly use a goto. */
1671 HeNEXT(entry) = aep[j];
1672 aep[j] = entry;
1673 }
1674 } else
1675 #endif
1676 {
1677 /* see comment above about duplicated code */
1678 HeNEXT(entry) = aep[j];
1679 aep[j] = entry;
1680 }
1681 }
1682 else {
1683 oentry = &HeNEXT(entry);
1684 }
1685 entry = *oentry;
1686 } while (entry);
1687 } while (i++ < oldsize);
1688 }
1689
1690 /*
1691 =for apidoc hv_ksplit
1692
1693 Attempt to grow the hash C<hv> so it has at least C<newmax> buckets available.
1694 Perl chooses the actual number for its convenience.
1695
1696 This is the same as doing the following in Perl code:
1697
1698 keys %hv = newmax;
1699
1700 =cut
1701 */
1702
1703 void
Perl_hv_ksplit(pTHX_ HV * hv,IV newmax)1704 Perl_hv_ksplit(pTHX_ HV *hv, IV newmax)
1705 {
1706 XPVHV* xhv = (XPVHV*)SvANY(hv);
1707 const I32 oldsize = (I32) xhv->xhv_max+1; /* HvMAX(hv)+1 */
1708 I32 newsize;
1709 I32 wantsize;
1710 I32 trysize;
1711 char *a;
1712
1713 PERL_ARGS_ASSERT_HV_KSPLIT;
1714
1715 wantsize = (I32) newmax; /* possible truncation here */
1716 if (wantsize != newmax)
1717 return;
1718
1719 wantsize= wantsize + (wantsize >> 1); /* wantsize *= 1.5 */
1720 if (wantsize < newmax) /* overflow detection */
1721 return;
1722
1723 newsize = oldsize;
1724 while (wantsize > newsize) {
1725 trysize = newsize << 1;
1726 if (trysize > newsize) {
1727 newsize = trysize;
1728 } else {
1729 /* we overflowed */
1730 return;
1731 }
1732 }
1733
1734 if (newsize <= oldsize)
1735 return; /* overflow detection */
1736
1737 a = (char *) HvARRAY(hv);
1738 if (a) {
1739 #ifdef PERL_HASH_RANDOMIZE_KEYS
1740 U32 was_ook = HvHasAUX(hv);
1741 #endif
1742 hsplit(hv, oldsize, newsize);
1743 #ifdef PERL_HASH_RANDOMIZE_KEYS
1744 if (was_ook && HvHasAUX(hv) && HvTOTALKEYS(hv)) {
1745 MAYBE_UPDATE_HASH_RAND_BITS();
1746 HvAUX(hv)->xhv_rand = (U32)PL_hash_rand_bits;
1747 }
1748 #endif
1749 } else {
1750 if (LARGE_HASH_HEURISTIC(hv, newmax))
1751 HvSHAREKEYS_off(hv);
1752 Newxz(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize), char);
1753 xhv->xhv_max = newsize - 1;
1754 HvARRAY(hv) = (HE **) a;
1755 }
1756 }
1757
1758 /* IMO this should also handle cases where hv_max is smaller than hv_keys
1759 * as tied hashes could play silly buggers and mess us around. We will
1760 * do the right thing during hv_store() afterwards, but still - Yves */
1761 #define HV_SET_MAX_ADJUSTED_FOR_KEYS(hv,hv_max,hv_keys) STMT_START {\
1762 /* Can we use fewer buckets? (hv_max is always 2^n-1) */ \
1763 if (hv_max < PERL_HASH_DEFAULT_HvMAX) { \
1764 hv_max = PERL_HASH_DEFAULT_HvMAX; \
1765 } else { \
1766 while (hv_max > PERL_HASH_DEFAULT_HvMAX && hv_max + 1 >= hv_keys * 2) \
1767 hv_max = hv_max / 2; \
1768 } \
1769 HvMAX(hv) = hv_max; \
1770 } STMT_END
1771
1772
1773 /*
1774 =for apidoc newHVhv
1775
1776 The content of C<ohv> is copied to a new hash. A pointer to the new hash is
1777 returned.
1778
1779 =cut
1780 */
1781
1782 HV *
Perl_newHVhv(pTHX_ HV * ohv)1783 Perl_newHVhv(pTHX_ HV *ohv)
1784 {
1785 HV * const hv = newHV();
1786 STRLEN hv_max;
1787
1788 if (!ohv || (!HvTOTALKEYS(ohv) && !SvMAGICAL((const SV *)ohv)))
1789 return hv;
1790 hv_max = HvMAX(ohv);
1791
1792 if (!SvMAGICAL((const SV *)ohv)) {
1793 /* It's an ordinary hash, so copy it fast. AMS 20010804 */
1794 STRLEN i;
1795 HE **ents, ** const oents = (HE **)HvARRAY(ohv);
1796 char *a;
1797 Newx(a, PERL_HV_ARRAY_ALLOC_BYTES(hv_max+1), char);
1798 ents = (HE**)a;
1799
1800 if (HvSHAREKEYS(ohv)) {
1801 #ifdef NODEFAULT_SHAREKEYS
1802 HvSHAREKEYS_on(hv);
1803 #else
1804 /* Shared is the default - it should have been set by newHV(). */
1805 assert(HvSHAREKEYS(hv));
1806 #endif
1807 }
1808 else {
1809 HvSHAREKEYS_off(hv);
1810 }
1811
1812 /* In each bucket... */
1813 for (i = 0; i <= hv_max; i++) {
1814 HE *prev = NULL;
1815 HE *oent = oents[i];
1816
1817 if (!oent) {
1818 ents[i] = NULL;
1819 continue;
1820 }
1821
1822 /* Copy the linked list of entries. */
1823 for (; oent; oent = HeNEXT(oent)) {
1824 HE * const ent = new_HE();
1825 SV *const val = HeVAL(oent);
1826 const int flags = HeKFLAGS(oent);
1827
1828 HeVAL(ent) = SvIMMORTAL(val) ? val : newSVsv(val);
1829 if ((flags & HVhek_NOTSHARED) == 0) {
1830 HeKEY_hek(ent) = share_hek_hek(HeKEY_hek(oent));
1831 }
1832 else {
1833 const U32 hash = HeHASH(oent);
1834 const char * const key = HeKEY(oent);
1835 const STRLEN len = HeKLEN(oent);
1836 HeKEY_hek(ent) = save_hek_flags(key, len, hash, flags);
1837 }
1838 if (prev)
1839 HeNEXT(prev) = ent;
1840 else
1841 ents[i] = ent;
1842 prev = ent;
1843 HeNEXT(ent) = NULL;
1844 }
1845 }
1846
1847 HvMAX(hv) = hv_max;
1848 HvTOTALKEYS(hv) = HvTOTALKEYS(ohv);
1849 HvARRAY(hv) = ents;
1850 } /* not magical */
1851 else {
1852 /* Iterate over ohv, copying keys and values one at a time. */
1853 HE *entry;
1854 const I32 riter = HvRITER_get(ohv);
1855 HE * const eiter = HvEITER_get(ohv);
1856 STRLEN hv_keys = HvTOTALKEYS(ohv);
1857
1858 HV_SET_MAX_ADJUSTED_FOR_KEYS(hv,hv_max,hv_keys);
1859
1860 hv_iterinit(ohv);
1861 while ((entry = hv_iternext_flags(ohv, 0))) {
1862 SV *val = hv_iterval(ohv,entry);
1863 SV * const keysv = HeSVKEY(entry);
1864 val = SvIMMORTAL(val) ? val : newSVsv(val);
1865 if (keysv)
1866 (void)hv_store_ent(hv, keysv, val, 0);
1867 else
1868 (void)hv_store_flags(hv, HeKEY(entry), HeKLEN(entry), val,
1869 HeHASH(entry), HeKFLAGS(entry));
1870 }
1871 HvRITER_set(ohv, riter);
1872 HvEITER_set(ohv, eiter);
1873 }
1874
1875 return hv;
1876 }
1877
1878 /*
1879 =for apidoc hv_copy_hints_hv
1880
1881 A specialised version of L</newHVhv> for copying C<%^H>. C<ohv> must be
1882 a pointer to a hash (which may have C<%^H> magic, but should be generally
1883 non-magical), or C<NULL> (interpreted as an empty hash). The content
1884 of C<ohv> is copied to a new hash, which has the C<%^H>-specific magic
1885 added to it. A pointer to the new hash is returned.
1886
1887 =cut
1888 */
1889
1890 HV *
Perl_hv_copy_hints_hv(pTHX_ HV * const ohv)1891 Perl_hv_copy_hints_hv(pTHX_ HV *const ohv)
1892 {
1893 HV * const hv = newHV();
1894
1895 if (ohv) {
1896 STRLEN hv_max = HvMAX(ohv);
1897 STRLEN hv_keys = HvTOTALKEYS(ohv);
1898 HE *entry;
1899 const I32 riter = HvRITER_get(ohv);
1900 HE * const eiter = HvEITER_get(ohv);
1901
1902 ENTER;
1903 SAVEFREESV(hv);
1904
1905 HV_SET_MAX_ADJUSTED_FOR_KEYS(hv,hv_max,hv_keys);
1906
1907 hv_iterinit(ohv);
1908 while ((entry = hv_iternext_flags(ohv, 0))) {
1909 SV *const sv = newSVsv(hv_iterval(ohv,entry));
1910 SV *heksv = HeSVKEY(entry);
1911 if (!heksv && sv) heksv = newSVhek(HeKEY_hek(entry));
1912 if (sv) sv_magic(sv, NULL, PERL_MAGIC_hintselem,
1913 (char *)heksv, HEf_SVKEY);
1914 if (heksv == HeSVKEY(entry))
1915 (void)hv_store_ent(hv, heksv, sv, 0);
1916 else {
1917 (void)hv_common(hv, heksv, HeKEY(entry), HeKLEN(entry),
1918 HeKFLAGS(entry), HV_FETCH_ISSTORE|HV_FETCH_JUST_SV, sv, HeHASH(entry));
1919 SvREFCNT_dec_NN(heksv);
1920 }
1921 }
1922 HvRITER_set(ohv, riter);
1923 HvEITER_set(ohv, eiter);
1924
1925 SvREFCNT_inc_simple_void_NN(hv);
1926 LEAVE;
1927 }
1928 hv_magic(hv, NULL, PERL_MAGIC_hints);
1929 return hv;
1930 }
1931 #undef HV_SET_MAX_ADJUSTED_FOR_KEYS
1932
1933 /* like hv_free_ent, but returns the SV rather than freeing it */
1934 STATIC SV*
S_hv_free_ent_ret(pTHX_ HE * entry)1935 S_hv_free_ent_ret(pTHX_ HE *entry)
1936 {
1937 PERL_ARGS_ASSERT_HV_FREE_ENT_RET;
1938
1939 SV *val = HeVAL(entry);
1940 if (HeKLEN(entry) == HEf_SVKEY) {
1941 SvREFCNT_dec(HeKEY_sv(entry));
1942 Safefree(HeKEY_hek(entry));
1943 }
1944 else if ((HeKFLAGS(entry) & HVhek_NOTSHARED) == 0) {
1945 unshare_hek(HeKEY_hek(entry));
1946 }
1947 else {
1948 Safefree(HeKEY_hek(entry));
1949 }
1950 del_HE(entry);
1951 return val;
1952 }
1953
1954
1955 void
Perl_hv_free_ent(pTHX_ HV * notused,HE * entry)1956 Perl_hv_free_ent(pTHX_ HV *notused, HE *entry)
1957 {
1958 PERL_UNUSED_ARG(notused);
1959
1960 if (!entry)
1961 return;
1962
1963 SV *val = hv_free_ent_ret(entry);
1964 SvREFCNT_dec(val);
1965 }
1966
1967
1968 void
Perl_hv_delayfree_ent(pTHX_ HV * notused,HE * entry)1969 Perl_hv_delayfree_ent(pTHX_ HV *notused, HE *entry)
1970 {
1971 PERL_UNUSED_ARG(notused);
1972
1973 if (!entry)
1974 return;
1975 /* SvREFCNT_inc to counter the SvREFCNT_dec in hv_free_ent */
1976 sv_2mortal(SvREFCNT_inc(HeVAL(entry))); /* free between statements */
1977 if (HeKLEN(entry) == HEf_SVKEY) {
1978 sv_2mortal(SvREFCNT_inc(HeKEY_sv(entry)));
1979 }
1980 hv_free_ent(NULL, entry);
1981 }
1982
1983 /*
1984 =for apidoc hv_clear
1985
1986 Frees all the elements of a hash, leaving it empty.
1987 The XS equivalent of C<%hash = ()>. See also L</hv_undef>.
1988
1989 See L</av_clear> for a note about the hash possibly being invalid on
1990 return.
1991
1992 =cut
1993 */
1994
1995 void
Perl_hv_clear(pTHX_ HV * hv)1996 Perl_hv_clear(pTHX_ HV *hv)
1997 {
1998 SSize_t orig_ix;
1999
2000 if (!hv)
2001 return;
2002
2003 DEBUG_A(Perl_hv_assert(aTHX_ hv));
2004
2005 /* avoid hv being freed when calling destructors below */
2006 EXTEND_MORTAL(1);
2007 PL_tmps_stack[++PL_tmps_ix] = SvREFCNT_inc_simple_NN(hv);
2008 orig_ix = PL_tmps_ix;
2009 if (SvREADONLY(hv) && HvTOTALKEYS(hv)) {
2010 /* restricted hash: convert all keys to placeholders */
2011 STRLEN max = HvMAX(hv);
2012 STRLEN i;
2013 for (i = 0; i <= max; i++) {
2014 HE *entry = (HvARRAY(hv))[i];
2015 for (; entry; entry = HeNEXT(entry)) {
2016 /* not already placeholder */
2017 if (HeVAL(entry) != &PL_sv_placeholder) {
2018 if (HeVAL(entry)) {
2019 if (SvREADONLY(HeVAL(entry))) {
2020 SV* const keysv = hv_iterkeysv(entry);
2021 Perl_croak_nocontext(
2022 "Attempt to delete readonly key '%" SVf "' from a restricted hash",
2023 (void*)keysv);
2024 }
2025 SvREFCNT_dec_NN(HeVAL(entry));
2026 }
2027 HeVAL(entry) = &PL_sv_placeholder;
2028 HvPLACEHOLDERS(hv)++;
2029 }
2030 }
2031 }
2032 }
2033 else {
2034 hv_free_entries(hv);
2035 HvPLACEHOLDERS_set(hv, 0);
2036
2037 if (SvRMAGICAL(hv))
2038 mg_clear(MUTABLE_SV(hv));
2039
2040 HvHASKFLAGS_off(hv);
2041 }
2042 if (HvHasAUX(hv)) {
2043 if(HvENAME_get(hv))
2044 mro_isa_changed_in(hv);
2045 HvEITER_set(hv, NULL);
2046 }
2047 /* disarm hv's premature free guard */
2048 if (LIKELY(PL_tmps_ix == orig_ix))
2049 PL_tmps_ix--;
2050 else
2051 PL_tmps_stack[orig_ix] = &PL_sv_undef;
2052 SvREFCNT_dec_NN(hv);
2053 }
2054
2055 /*
2056 =for apidoc hv_clear_placeholders
2057
2058 Clears any placeholders from a hash. If a restricted hash has any of its keys
2059 marked as readonly and the key is subsequently deleted, the key is not actually
2060 deleted but is marked by assigning it a value of C<&PL_sv_placeholder>. This tags
2061 it so it will be ignored by future operations such as iterating over the hash,
2062 but will still allow the hash to have a value reassigned to the key at some
2063 future point. This function clears any such placeholder keys from the hash.
2064 See C<L<Hash::Util::lock_keys()|Hash::Util/lock_keys>> for an example of its
2065 use.
2066
2067 =cut
2068 */
2069
2070 void
Perl_hv_clear_placeholders(pTHX_ HV * hv)2071 Perl_hv_clear_placeholders(pTHX_ HV *hv)
2072 {
2073 const U32 items = (U32)HvPLACEHOLDERS_get(hv);
2074
2075 PERL_ARGS_ASSERT_HV_CLEAR_PLACEHOLDERS;
2076
2077 if (items)
2078 clear_placeholders(hv, items);
2079 }
2080
2081 static void
S_clear_placeholders(pTHX_ HV * hv,const U32 placeholders)2082 S_clear_placeholders(pTHX_ HV *hv, const U32 placeholders)
2083 {
2084 I32 i;
2085 U32 to_find = placeholders;
2086
2087 PERL_ARGS_ASSERT_CLEAR_PLACEHOLDERS;
2088
2089 assert(to_find);
2090
2091 i = HvMAX(hv);
2092 do {
2093 /* Loop down the linked list heads */
2094 HE **oentry = &(HvARRAY(hv))[i];
2095 HE *entry;
2096
2097 while ((entry = *oentry)) {
2098 if (HeVAL(entry) == &PL_sv_placeholder) {
2099 *oentry = HeNEXT(entry);
2100 if (entry == HvEITER_get(hv))
2101 HvLAZYDEL_on(hv);
2102 else {
2103 if (HvHasAUX(hv) && HvLAZYDEL(hv) &&
2104 entry == HeNEXT(HvAUX(hv)->xhv_eiter))
2105 HeNEXT(HvAUX(hv)->xhv_eiter) = HeNEXT(entry);
2106 hv_free_ent(NULL, entry);
2107 }
2108
2109 if (--to_find == 0) {
2110 /* Finished. */
2111 HvTOTALKEYS(hv) -= (IV)placeholders;
2112 if (HvTOTALKEYS(hv) == 0)
2113 HvHASKFLAGS_off(hv);
2114 HvPLACEHOLDERS_set(hv, 0);
2115 return;
2116 }
2117 } else {
2118 oentry = &HeNEXT(entry);
2119 }
2120 }
2121 } while (--i >= 0);
2122 /* You can't get here, hence assertion should always fail. */
2123 assert (to_find == 0);
2124 NOT_REACHED; /* NOTREACHED */
2125 }
2126
2127 STATIC void
S_hv_free_entries(pTHX_ HV * hv)2128 S_hv_free_entries(pTHX_ HV *hv)
2129 {
2130 STRLEN index = 0;
2131 SV *sv;
2132
2133 PERL_ARGS_ASSERT_HV_FREE_ENTRIES;
2134
2135 while ((sv = Perl_hfree_next_entry(aTHX_ hv, &index)) || HvTOTALKEYS(hv)) {
2136 SvREFCNT_dec(sv);
2137 }
2138 }
2139
2140
2141 /* hfree_next_entry()
2142 * For use only by S_hv_free_entries() and sv_clear().
2143 * Delete the next available HE from hv and return the associated SV.
2144 * Returns null on empty hash. Nevertheless null is not a reliable
2145 * indicator that the hash is empty, as the deleted entry may have a
2146 * null value.
2147 * indexp is a pointer to the current index into HvARRAY. The index should
2148 * initially be set to 0. hfree_next_entry() may update it. */
2149
2150 SV*
Perl_hfree_next_entry(pTHX_ HV * hv,STRLEN * indexp)2151 Perl_hfree_next_entry(pTHX_ HV *hv, STRLEN *indexp)
2152 {
2153 struct xpvhv_aux *iter;
2154 HE *entry;
2155 HE ** array;
2156 #ifdef DEBUGGING
2157 STRLEN orig_index = *indexp;
2158 #endif
2159
2160 PERL_ARGS_ASSERT_HFREE_NEXT_ENTRY;
2161
2162 if (HvHasAUX(hv) && ((iter = HvAUX(hv)))) {
2163 if ((entry = iter->xhv_eiter)) {
2164 /* the iterator may get resurrected after each
2165 * destructor call, so check each time */
2166 if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */
2167 HvLAZYDEL_off(hv);
2168 hv_free_ent(NULL, entry);
2169 /* warning: at this point HvARRAY may have been
2170 * re-allocated, HvMAX changed etc */
2171 }
2172 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
2173 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
2174 #ifdef PERL_HASH_RANDOMIZE_KEYS
2175 iter->xhv_last_rand = iter->xhv_rand;
2176 #endif
2177 }
2178 }
2179
2180 if (!((XPVHV*)SvANY(hv))->xhv_keys)
2181 return NULL;
2182
2183 array = HvARRAY(hv);
2184 assert(array);
2185 while ( ! ((entry = array[*indexp])) ) {
2186 if ((*indexp)++ >= HvMAX(hv))
2187 *indexp = 0;
2188 assert(*indexp != orig_index);
2189 }
2190 array[*indexp] = HeNEXT(entry);
2191 ((XPVHV*) SvANY(hv))->xhv_keys--;
2192
2193 if ( PL_phase != PERL_PHASE_DESTRUCT && HvHasENAME(hv)
2194 && HeVAL(entry) && isGV(HeVAL(entry))
2195 && GvHV(HeVAL(entry)) && HvHasENAME(GvHV(HeVAL(entry)))
2196 ) {
2197 STRLEN klen;
2198 const char * const key = HePV(entry,klen);
2199 if ((klen > 1 && key[klen-1]==':' && key[klen-2]==':')
2200 || (klen == 1 && key[0] == ':')) {
2201 mro_package_moved(
2202 NULL, GvHV(HeVAL(entry)),
2203 (GV *)HeVAL(entry), 0
2204 );
2205 }
2206 }
2207 return hv_free_ent_ret(entry);
2208 }
2209
2210
2211 /*
2212 =for apidoc hv_undef
2213
2214 Undefines the hash. The XS equivalent of C<undef(%hash)>.
2215
2216 As well as freeing all the elements of the hash (like C<hv_clear()>), this
2217 also frees any auxiliary data and storage associated with the hash.
2218
2219 See L</av_clear> for a note about the hash possibly being invalid on
2220 return.
2221
2222 =cut
2223 */
2224
2225 void
Perl_hv_undef_flags(pTHX_ HV * hv,U32 flags)2226 Perl_hv_undef_flags(pTHX_ HV *hv, U32 flags)
2227 {
2228 bool save;
2229 SSize_t orig_ix = PL_tmps_ix; /* silence compiler warning about uninitialized vars */
2230
2231 if (!hv)
2232 return;
2233 save = cBOOL(SvREFCNT(hv));
2234 DEBUG_A(Perl_hv_assert(aTHX_ hv));
2235
2236 /* The name must be deleted before the call to hv_free_entries so that
2237 CVs are anonymised properly. But the effective name must be pre-
2238 served until after that call (and only deleted afterwards if the
2239 call originated from sv_clear). For stashes with one name that is
2240 both the canonical name and the effective name, hv_name_set has to
2241 allocate an array for storing the effective name. We can skip that
2242 during global destruction, as it does not matter where the CVs point
2243 if they will be freed anyway. */
2244 /* note that the code following prior to hv_free_entries is duplicated
2245 * in sv_clear(), and changes here should be done there too */
2246 if (PL_phase != PERL_PHASE_DESTRUCT && HvHasNAME(hv)) {
2247 if (PL_stashcache) {
2248 DEBUG_o(Perl_deb(aTHX_ "hv_undef_flags clearing PL_stashcache for '%"
2249 HEKf "'\n", HEKfARG(HvNAME_HEK(hv))));
2250 (void)hv_deletehek(PL_stashcache, HvNAME_HEK(hv), G_DISCARD);
2251 }
2252 hv_name_set(hv, NULL, 0, 0);
2253 }
2254 if (save) {
2255 /* avoid hv being freed when calling destructors below */
2256 EXTEND_MORTAL(1);
2257 PL_tmps_stack[++PL_tmps_ix] = SvREFCNT_inc_simple_NN(hv);
2258 orig_ix = PL_tmps_ix;
2259 }
2260
2261 /* As well as any/all HE*s in HvARRAY(), this call also ensures that
2262 xhv_eiter is NULL, including handling the case of a tied hash partway
2263 through iteration where HvLAZYDEL() is true and xhv_eiter points to an
2264 HE* that needs to be explicitly freed. */
2265 hv_free_entries(hv);
2266
2267 /* HvHasAUX() is true for a hash if it has struct xpvhv_aux allocated. That
2268 structure has several other pieces of allocated memory - hence those must
2269 be freed before the structure itself can be freed. Some can be freed when
2270 a hash is "undefined" (this function), but some must persist until it is
2271 destroyed (which might be this function's immediate caller).
2272
2273 Hence the code in this block frees what it is logical to free (and NULLs
2274 out anything freed) so that the structure is left in a logically
2275 consistent state - pointers are NULL or point to valid memory, and
2276 non-pointer values are correct for an empty hash. The structure state
2277 must remain consistent, because this code can no longer clear SVf_OOK,
2278 meaning that this structure might be read again at any point in the
2279 future without further checks or reinitialisation. */
2280 if (HvHasAUX(hv)) {
2281 struct xpvhv_aux *aux = HvAUX(hv);
2282 struct mro_meta *meta;
2283 const char *name;
2284
2285 if (HvHasENAME(hv)) {
2286 if (PL_phase != PERL_PHASE_DESTRUCT)
2287 mro_isa_changed_in(hv);
2288 if (PL_stashcache) {
2289 DEBUG_o(Perl_deb(aTHX_ "hv_undef_flags clearing PL_stashcache for effective name '%"
2290 HEKf "'\n", HEKfARG(HvENAME_HEK_NN(hv))));
2291 (void)hv_deletehek(PL_stashcache, HvENAME_HEK_NN(hv), G_DISCARD);
2292 }
2293 }
2294
2295 /* If this call originated from sv_clear, then we must check for
2296 * effective names that need freeing, as well as the usual name. */
2297 name = HvNAME(hv);
2298 if (flags & HV_NAME_SETALL
2299 ? cBOOL(aux->xhv_name_u.xhvnameu_name)
2300 : cBOOL(name))
2301 {
2302 if (name && PL_stashcache) {
2303 DEBUG_o(Perl_deb(aTHX_ "hv_undef_flags clearing PL_stashcache for name '%"
2304 HEKf "'\n", HEKfARG(HvNAME_HEK_NN(hv))));
2305 (void)hv_deletehek(PL_stashcache, HvNAME_HEK_NN(hv), G_DISCARD);
2306 }
2307 hv_name_set(hv, NULL, 0, flags);
2308 }
2309 if((meta = aux->xhv_mro_meta)) {
2310 if (meta->mro_linear_all) {
2311 SvREFCNT_dec_NN(meta->mro_linear_all);
2312 /* mro_linear_current is just acting as a shortcut pointer,
2313 hence the else. */
2314 }
2315 else
2316 /* Only the current MRO is stored, so this owns the data.
2317 */
2318 SvREFCNT_dec(meta->mro_linear_current);
2319 SvREFCNT_dec(meta->mro_nextmethod);
2320 SvREFCNT_dec(meta->isa);
2321 SvREFCNT_dec(meta->super);
2322 Safefree(meta);
2323 aux->xhv_mro_meta = NULL;
2324 }
2325
2326 if(HvSTASH_IS_CLASS(hv)) {
2327 SvREFCNT_dec(aux->xhv_class_superclass);
2328 SvREFCNT_dec(aux->xhv_class_initfields_cv);
2329 SvREFCNT_dec(aux->xhv_class_adjust_blocks);
2330 if(aux->xhv_class_fields)
2331 PadnamelistREFCNT_dec(aux->xhv_class_fields);
2332 SvREFCNT_dec(aux->xhv_class_param_map);
2333 Safefree(aux->xhv_class_suspended_initfields_compcv);
2334 aux->xhv_class_suspended_initfields_compcv = NULL;
2335
2336 aux->xhv_aux_flags &= ~HvAUXf_IS_CLASS;
2337 }
2338 }
2339
2340 Safefree(HvARRAY(hv));
2341 HvMAX(hv) = PERL_HASH_DEFAULT_HvMAX; /* 7 (it's a normal hash) */
2342 HvARRAY(hv) = 0;
2343
2344 /* if we're freeing the HV, the SvMAGIC field has been reused for
2345 * other purposes, and so there can't be any placeholder magic */
2346 if (SvREFCNT(hv))
2347 HvPLACEHOLDERS_set(hv, 0);
2348
2349 if (SvRMAGICAL(hv))
2350 mg_clear(MUTABLE_SV(hv));
2351
2352 if (save) {
2353 /* disarm hv's premature free guard */
2354 if (LIKELY(PL_tmps_ix == orig_ix))
2355 PL_tmps_ix--;
2356 else
2357 PL_tmps_stack[orig_ix] = &PL_sv_undef;
2358 SvREFCNT_dec_NN(hv);
2359 }
2360 }
2361
2362 /*
2363 =for apidoc hv_fill
2364
2365 Returns the number of hash buckets that happen to be in use.
2366
2367 This function implements the L<C<HvFILL> macro|perlapi/HvFILL> which you should
2368 use instead.
2369
2370 As of perl 5.25 this function is used only for debugging
2371 purposes, and the number of used hash buckets is not
2372 in any way cached, thus this function can be costly
2373 to execute as it must iterate over all the buckets in the
2374 hash.
2375
2376 =cut
2377 */
2378
2379 STRLEN
Perl_hv_fill(pTHX_ HV * const hv)2380 Perl_hv_fill(pTHX_ HV *const hv)
2381 {
2382 STRLEN count = 0;
2383 HE **ents = HvARRAY(hv);
2384
2385 PERL_UNUSED_CONTEXT;
2386 PERL_ARGS_ASSERT_HV_FILL;
2387
2388 /* No keys implies no buckets used.
2389 One key can only possibly mean one bucket used. */
2390 if (HvTOTALKEYS(hv) < 2)
2391 return HvTOTALKEYS(hv);
2392
2393 if (ents) {
2394 /* I wonder why we count down here...
2395 * Is it some micro-optimisation?
2396 * I would have thought counting up was better.
2397 * - Yves
2398 */
2399 HE *const *const last = ents + HvMAX(hv);
2400 count = last + 1 - ents;
2401
2402 do {
2403 if (!*ents)
2404 --count;
2405 } while (++ents <= last);
2406 }
2407 return count;
2408 }
2409
2410 static struct xpvhv_aux*
S_hv_auxinit(pTHX_ HV * hv)2411 S_hv_auxinit(pTHX_ HV *hv) {
2412 struct xpvhv_aux *iter;
2413
2414 PERL_ARGS_ASSERT_HV_AUXINIT;
2415
2416 if (!HvHasAUX(hv)) {
2417 char *array = (char *) HvARRAY(hv);
2418 if (!array) {
2419 Newxz(array, PERL_HV_ARRAY_ALLOC_BYTES(HvMAX(hv) + 1), char);
2420 HvARRAY(hv) = (HE**)array;
2421 }
2422 iter = Perl_hv_auxalloc(aTHX_ hv);
2423 #ifdef PERL_HASH_RANDOMIZE_KEYS
2424 MAYBE_UPDATE_HASH_RAND_BITS();
2425 iter->xhv_rand = (U32)PL_hash_rand_bits;
2426 #endif
2427 } else {
2428 iter = HvAUX(hv);
2429 }
2430
2431 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
2432 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
2433 #ifdef PERL_HASH_RANDOMIZE_KEYS
2434 iter->xhv_last_rand = iter->xhv_rand;
2435 #endif
2436 iter->xhv_name_u.xhvnameu_name = 0;
2437 iter->xhv_name_count = 0;
2438 iter->xhv_backreferences = 0;
2439 iter->xhv_mro_meta = NULL;
2440 iter->xhv_aux_flags = 0;
2441 return iter;
2442 }
2443
2444 /*
2445 =for apidoc hv_iterinit
2446
2447 Prepares a starting point to traverse a hash table. Returns the number of
2448 keys in the hash, including placeholders (i.e. the same as C<HvTOTALKEYS(hv)>).
2449 The return value is currently only meaningful for hashes without tie magic.
2450
2451 NOTE: Before version 5.004_65, C<hv_iterinit> used to return the number of
2452 hash buckets that happen to be in use. If you still need that esoteric
2453 value, you can get it through the macro C<HvFILL(hv)>.
2454
2455
2456 =cut
2457 */
2458
2459 I32
Perl_hv_iterinit(pTHX_ HV * hv)2460 Perl_hv_iterinit(pTHX_ HV *hv)
2461 {
2462 PERL_ARGS_ASSERT_HV_ITERINIT;
2463
2464 if (HvHasAUX(hv)) {
2465 struct xpvhv_aux * iter = HvAUX(hv);
2466 HE * const entry = iter->xhv_eiter; /* HvEITER(hv) */
2467 if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */
2468 HvLAZYDEL_off(hv);
2469 hv_free_ent(NULL, entry);
2470 }
2471 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
2472 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
2473 #ifdef PERL_HASH_RANDOMIZE_KEYS
2474 iter->xhv_last_rand = iter->xhv_rand;
2475 #endif
2476 } else {
2477 hv_auxinit(hv);
2478 }
2479
2480 /* note this includes placeholders! */
2481 return HvTOTALKEYS(hv);
2482 }
2483
2484 /*
2485 =for apidoc hv_riter_p
2486
2487 Implements C<HvRITER> which you should use instead.
2488
2489 =cut
2490 */
2491
2492 I32 *
Perl_hv_riter_p(pTHX_ HV * hv)2493 Perl_hv_riter_p(pTHX_ HV *hv) {
2494 struct xpvhv_aux *iter;
2495
2496 PERL_ARGS_ASSERT_HV_RITER_P;
2497
2498 iter = HvHasAUX(hv) ? HvAUX(hv) : hv_auxinit(hv);
2499 return &(iter->xhv_riter);
2500 }
2501
2502 /*
2503 =for apidoc hv_eiter_p
2504
2505 Implements C<HvEITER> which you should use instead.
2506
2507 =cut
2508 */
2509
2510 HE **
Perl_hv_eiter_p(pTHX_ HV * hv)2511 Perl_hv_eiter_p(pTHX_ HV *hv) {
2512 struct xpvhv_aux *iter;
2513
2514 PERL_ARGS_ASSERT_HV_EITER_P;
2515
2516 iter = HvHasAUX(hv) ? HvAUX(hv) : hv_auxinit(hv);
2517 return &(iter->xhv_eiter);
2518 }
2519
2520 /*
2521 =for apidoc hv_riter_set
2522
2523 Implements C<HvRITER_set> which you should use instead.
2524
2525 =cut
2526 */
2527
2528 void
Perl_hv_riter_set(pTHX_ HV * hv,I32 riter)2529 Perl_hv_riter_set(pTHX_ HV *hv, I32 riter) {
2530 struct xpvhv_aux *iter;
2531
2532 PERL_ARGS_ASSERT_HV_RITER_SET;
2533
2534 if (HvHasAUX(hv)) {
2535 iter = HvAUX(hv);
2536 } else {
2537 if (riter == -1)
2538 return;
2539
2540 iter = hv_auxinit(hv);
2541 }
2542 iter->xhv_riter = riter;
2543 }
2544
2545 void
Perl_hv_rand_set(pTHX_ HV * hv,U32 new_xhv_rand)2546 Perl_hv_rand_set(pTHX_ HV *hv, U32 new_xhv_rand) {
2547 struct xpvhv_aux *iter;
2548
2549 PERL_ARGS_ASSERT_HV_RAND_SET;
2550
2551 #ifdef PERL_HASH_RANDOMIZE_KEYS
2552 if (HvHasAUX(hv)) {
2553 iter = HvAUX(hv);
2554 } else {
2555 iter = hv_auxinit(hv);
2556 }
2557 iter->xhv_rand = new_xhv_rand;
2558 #else
2559 Perl_croak(aTHX_ "This Perl has not been built with support for randomized hash key traversal but something called Perl_hv_rand_set().");
2560 #endif
2561 }
2562
2563 /*
2564 =for apidoc hv_eiter_set
2565
2566 Implements C<HvEITER_set> which you should use instead.
2567
2568 =cut
2569 */
2570
2571 void
Perl_hv_eiter_set(pTHX_ HV * hv,HE * eiter)2572 Perl_hv_eiter_set(pTHX_ HV *hv, HE *eiter) {
2573 struct xpvhv_aux *iter;
2574
2575 PERL_ARGS_ASSERT_HV_EITER_SET;
2576
2577 if (HvHasAUX(hv)) {
2578 iter = HvAUX(hv);
2579 } else {
2580 /* 0 is the default so don't go malloc()ing a new structure just to
2581 hold 0. */
2582 if (!eiter)
2583 return;
2584
2585 iter = hv_auxinit(hv);
2586 }
2587 iter->xhv_eiter = eiter;
2588 }
2589
2590 /*
2591 =for apidoc hv_name_set
2592 =for apidoc_item ||hv_name_sets|HV *hv|"name"|U32 flags
2593
2594 These each set the name of stash C<hv> to the specified name.
2595
2596 They differ only in how the name is specified.
2597
2598 In C<hv_name_sets>, the name is a literal C string, enclosed in double quotes.
2599
2600 In C<hv_name_set>, C<name> points to the first byte of the name, and an
2601 additional parameter, C<len>, specifies its length in bytes. Hence, the name
2602 may contain embedded-NUL characters.
2603
2604 If C<SVf_UTF8> is set in C<flags>, the name is treated as being in UTF-8;
2605 otherwise not.
2606
2607 If C<HV_NAME_SETALL> is set in C<flags>, both the name and the effective name
2608 are set.
2609
2610 =for apidoc Amnh||HV_NAME_SETALL
2611
2612 =cut
2613 */
2614
2615 void
Perl_hv_name_set(pTHX_ HV * hv,const char * name,U32 len,U32 flags)2616 Perl_hv_name_set(pTHX_ HV *hv, const char *name, U32 len, U32 flags)
2617 {
2618 struct xpvhv_aux *iter;
2619 U32 hash;
2620 HEK **spot;
2621
2622 PERL_ARGS_ASSERT_HV_NAME_SET;
2623
2624 if (len > I32_MAX)
2625 Perl_croak(aTHX_ "panic: hv name too long (%" UVuf ")", (UV) len);
2626
2627 if (HvHasAUX(hv)) {
2628 iter = HvAUX(hv);
2629 if (iter->xhv_name_u.xhvnameu_name) {
2630 if(iter->xhv_name_count) {
2631 if(flags & HV_NAME_SETALL) {
2632 HEK ** const this_name = HvAUX(hv)->xhv_name_u.xhvnameu_names;
2633 HEK **hekp = this_name + (
2634 iter->xhv_name_count < 0
2635 ? -iter->xhv_name_count
2636 : iter->xhv_name_count
2637 );
2638 while(hekp-- > this_name+1)
2639 unshare_hek_or_pvn(*hekp, 0, 0, 0);
2640 /* The first elem may be null. */
2641 if(*this_name) unshare_hek_or_pvn(*this_name, 0, 0, 0);
2642 Safefree(this_name);
2643 spot = &iter->xhv_name_u.xhvnameu_name;
2644 iter->xhv_name_count = 0;
2645 }
2646 else {
2647 if(iter->xhv_name_count > 0) {
2648 /* shift some things over */
2649 Renew(
2650 iter->xhv_name_u.xhvnameu_names, iter->xhv_name_count + 1, HEK *
2651 );
2652 spot = iter->xhv_name_u.xhvnameu_names;
2653 spot[iter->xhv_name_count] = spot[1];
2654 spot[1] = spot[0];
2655 iter->xhv_name_count = -(iter->xhv_name_count + 1);
2656 }
2657 else if(*(spot = iter->xhv_name_u.xhvnameu_names)) {
2658 unshare_hek_or_pvn(*spot, 0, 0, 0);
2659 }
2660 }
2661 }
2662 else if (flags & HV_NAME_SETALL) {
2663 unshare_hek_or_pvn(iter->xhv_name_u.xhvnameu_name, 0, 0, 0);
2664 spot = &iter->xhv_name_u.xhvnameu_name;
2665 }
2666 else {
2667 HEK * const existing_name = iter->xhv_name_u.xhvnameu_name;
2668 Newx(iter->xhv_name_u.xhvnameu_names, 2, HEK *);
2669 iter->xhv_name_count = -2;
2670 spot = iter->xhv_name_u.xhvnameu_names;
2671 spot[1] = existing_name;
2672 }
2673 }
2674 else { spot = &iter->xhv_name_u.xhvnameu_name; iter->xhv_name_count = 0; }
2675 } else {
2676 if (name == 0)
2677 return;
2678
2679 iter = hv_auxinit(hv);
2680 spot = &iter->xhv_name_u.xhvnameu_name;
2681 }
2682 PERL_HASH(hash, name, len);
2683 *spot = name ? share_hek(name, flags & SVf_UTF8 ? -(I32)len : (I32)len, hash) : NULL;
2684 }
2685
2686 /*
2687 This is basically sv_eq_flags() in sv.c, but we avoid the magic
2688 and bytes checking.
2689 */
2690
2691 STATIC I32
hek_eq_pvn_flags(pTHX_ const HEK * hek,const char * pv,const I32 pvlen,const U32 flags)2692 hek_eq_pvn_flags(pTHX_ const HEK *hek, const char* pv, const I32 pvlen, const U32 flags) {
2693 if ( (HEK_UTF8(hek) ? 1 : 0) != (flags & SVf_UTF8 ? 1 : 0) ) {
2694 if (flags & SVf_UTF8)
2695 return (bytes_cmp_utf8(
2696 (const U8*)HEK_KEY(hek), HEK_LEN(hek),
2697 (const U8*)pv, pvlen) == 0);
2698 else
2699 return (bytes_cmp_utf8(
2700 (const U8*)pv, pvlen,
2701 (const U8*)HEK_KEY(hek), HEK_LEN(hek)) == 0);
2702 }
2703 else
2704 return HEK_LEN(hek) == pvlen && ((HEK_KEY(hek) == pv)
2705 || memEQ(HEK_KEY(hek), pv, pvlen));
2706 }
2707
2708 /*
2709 =for apidoc hv_ename_add
2710
2711 Adds a name to a stash's internal list of effective names. See
2712 C<L</hv_ename_delete>>.
2713
2714 This is called when a stash is assigned to a new location in the symbol
2715 table.
2716
2717 =cut
2718 */
2719
2720 void
Perl_hv_ename_add(pTHX_ HV * hv,const char * name,U32 len,U32 flags)2721 Perl_hv_ename_add(pTHX_ HV *hv, const char *name, U32 len, U32 flags)
2722 {
2723 struct xpvhv_aux *aux = HvHasAUX(hv) ? HvAUX(hv) : hv_auxinit(hv);
2724 U32 hash;
2725
2726 PERL_ARGS_ASSERT_HV_ENAME_ADD;
2727
2728 if (len > I32_MAX)
2729 Perl_croak(aTHX_ "panic: hv name too long (%" UVuf ")", (UV) len);
2730
2731 PERL_HASH(hash, name, len);
2732
2733 if (aux->xhv_name_count) {
2734 I32 count = aux->xhv_name_count;
2735 HEK ** const xhv_name = aux->xhv_name_u.xhvnameu_names + (count<0);
2736 HEK **hekp = xhv_name + (count < 0 ? -count - 1 : count);
2737 while (hekp-- > xhv_name)
2738 {
2739 assert(*hekp);
2740 if (
2741 (HEK_UTF8(*hekp) || (flags & SVf_UTF8))
2742 ? hek_eq_pvn_flags(aTHX_ *hekp, name, (I32)len, flags)
2743 : (HEK_LEN(*hekp) == (I32)len && memEQ(HEK_KEY(*hekp), name, len))
2744 ) {
2745 if (hekp == xhv_name && count < 0)
2746 aux->xhv_name_count = -count;
2747 return;
2748 }
2749 }
2750 if (count < 0) aux->xhv_name_count--, count = -count;
2751 else aux->xhv_name_count++;
2752 Renew(aux->xhv_name_u.xhvnameu_names, count + 1, HEK *);
2753 (aux->xhv_name_u.xhvnameu_names)[count] = share_hek(name, (flags & SVf_UTF8 ? -(I32)len : (I32)len), hash);
2754 }
2755 else {
2756 HEK *existing_name = aux->xhv_name_u.xhvnameu_name;
2757 if (
2758 existing_name && (
2759 (HEK_UTF8(existing_name) || (flags & SVf_UTF8))
2760 ? hek_eq_pvn_flags(aTHX_ existing_name, name, (I32)len, flags)
2761 : (HEK_LEN(existing_name) == (I32)len && memEQ(HEK_KEY(existing_name), name, len))
2762 )
2763 ) return;
2764 Newx(aux->xhv_name_u.xhvnameu_names, 2, HEK *);
2765 aux->xhv_name_count = existing_name ? 2 : -2;
2766 *aux->xhv_name_u.xhvnameu_names = existing_name;
2767 (aux->xhv_name_u.xhvnameu_names)[1] = share_hek(name, (flags & SVf_UTF8 ? -(I32)len : (I32)len), hash);
2768 }
2769 }
2770
2771 /*
2772 =for apidoc hv_ename_delete
2773
2774 Removes a name from a stash's internal list of effective names. If this is
2775 the name returned by C<HvENAME>, then another name in the list will take
2776 its place (C<HvENAME> will use it).
2777
2778 This is called when a stash is deleted from the symbol table.
2779
2780 =cut
2781 */
2782
2783 void
Perl_hv_ename_delete(pTHX_ HV * hv,const char * name,U32 len,U32 flags)2784 Perl_hv_ename_delete(pTHX_ HV *hv, const char *name, U32 len, U32 flags)
2785 {
2786 struct xpvhv_aux *aux;
2787
2788 PERL_ARGS_ASSERT_HV_ENAME_DELETE;
2789
2790 if (len > I32_MAX)
2791 Perl_croak(aTHX_ "panic: hv name too long (%" UVuf ")", (UV) len);
2792
2793 if (!HvHasAUX(hv)) return;
2794
2795 aux = HvAUX(hv);
2796 if (!aux->xhv_name_u.xhvnameu_name) return;
2797
2798 if (aux->xhv_name_count) {
2799 HEK ** const namep = aux->xhv_name_u.xhvnameu_names;
2800 I32 const count = aux->xhv_name_count;
2801 HEK **victim = namep + (count < 0 ? -count : count);
2802 while (victim-- > namep + 1)
2803 if (
2804 (HEK_UTF8(*victim) || (flags & SVf_UTF8))
2805 ? hek_eq_pvn_flags(aTHX_ *victim, name, (I32)len, flags)
2806 : (HEK_LEN(*victim) == (I32)len && memEQ(HEK_KEY(*victim), name, len))
2807 ) {
2808 unshare_hek_or_pvn(*victim, 0, 0, 0);
2809 if (count < 0) ++aux->xhv_name_count;
2810 else --aux->xhv_name_count;
2811 if (
2812 (aux->xhv_name_count == 1 || aux->xhv_name_count == -1)
2813 && !*namep
2814 ) { /* if there are none left */
2815 Safefree(namep);
2816 aux->xhv_name_u.xhvnameu_names = NULL;
2817 aux->xhv_name_count = 0;
2818 }
2819 else {
2820 /* Move the last one back to fill the empty slot. It
2821 does not matter what order they are in. */
2822 *victim = *(namep + (count < 0 ? -count : count) - 1);
2823 }
2824 return;
2825 }
2826 if (
2827 count > 0 && ((HEK_UTF8(*namep) || (flags & SVf_UTF8))
2828 ? hek_eq_pvn_flags(aTHX_ *namep, name, (I32)len, flags)
2829 : (HEK_LEN(*namep) == (I32)len && memEQ(HEK_KEY(*namep), name, len))
2830 )
2831 ) {
2832 aux->xhv_name_count = -count;
2833 }
2834 }
2835 else if(
2836 (HEK_UTF8(aux->xhv_name_u.xhvnameu_name) || (flags & SVf_UTF8))
2837 ? hek_eq_pvn_flags(aTHX_ aux->xhv_name_u.xhvnameu_name, name, (I32)len, flags)
2838 : (HEK_LEN(aux->xhv_name_u.xhvnameu_name) == (I32)len &&
2839 memEQ(HEK_KEY(aux->xhv_name_u.xhvnameu_name), name, len))
2840 ) {
2841 HEK * const namehek = aux->xhv_name_u.xhvnameu_name;
2842 Newx(aux->xhv_name_u.xhvnameu_names, 1, HEK *);
2843 *aux->xhv_name_u.xhvnameu_names = namehek;
2844 aux->xhv_name_count = -1;
2845 }
2846 }
2847
2848 AV **
Perl_hv_backreferences_p(pTHX_ HV * hv)2849 Perl_hv_backreferences_p(pTHX_ HV *hv) {
2850 PERL_ARGS_ASSERT_HV_BACKREFERENCES_P;
2851 /* See also Perl_sv_get_backrefs in sv.c where this logic is unrolled */
2852 {
2853 struct xpvhv_aux * const iter = HvHasAUX(hv) ? HvAUX(hv) : hv_auxinit(hv);
2854 return &(iter->xhv_backreferences);
2855 }
2856 }
2857
2858 void
Perl_hv_kill_backrefs(pTHX_ HV * hv)2859 Perl_hv_kill_backrefs(pTHX_ HV *hv) {
2860 AV *av;
2861
2862 PERL_ARGS_ASSERT_HV_KILL_BACKREFS;
2863
2864 if (!HvHasAUX(hv))
2865 return;
2866
2867 av = HvAUX(hv)->xhv_backreferences;
2868
2869 if (av) {
2870 HvAUX(hv)->xhv_backreferences = 0;
2871 Perl_sv_kill_backrefs(aTHX_ MUTABLE_SV(hv), av);
2872 if (SvTYPE(av) == SVt_PVAV)
2873 SvREFCNT_dec_NN(av);
2874 }
2875 }
2876
2877 /*
2878 hv_iternext is implemented as a macro in hv.h
2879
2880 =for apidoc hv_iternext
2881
2882 Returns entries from a hash iterator. See C<L</hv_iterinit>>.
2883
2884 You may call C<hv_delete> or C<hv_delete_ent> on the hash entry that the
2885 iterator currently points to, without losing your place or invalidating your
2886 iterator. Note that in this case the current entry is deleted from the hash
2887 with your iterator holding the last reference to it. Your iterator is flagged
2888 to free the entry on the next call to C<hv_iternext>, so you must not discard
2889 your iterator immediately else the entry will leak - call C<hv_iternext> to
2890 trigger the resource deallocation.
2891
2892 =for apidoc hv_iternext_flags
2893
2894 Returns entries from a hash iterator. See C<L</hv_iterinit>> and
2895 C<L</hv_iternext>>.
2896 The C<flags> value will normally be zero; if C<HV_ITERNEXT_WANTPLACEHOLDERS> is
2897 set the placeholders keys (for restricted hashes) will be returned in addition
2898 to normal keys. By default placeholders are automatically skipped over.
2899 Currently a placeholder is implemented with a value that is
2900 C<&PL_sv_placeholder>. Note that the implementation of placeholders and
2901 restricted hashes may change, and the implementation currently is
2902 insufficiently abstracted for any change to be tidy.
2903
2904 =for apidoc Amnh||HV_ITERNEXT_WANTPLACEHOLDERS
2905
2906 =cut
2907 */
2908
2909 HE *
Perl_hv_iternext_flags(pTHX_ HV * hv,I32 flags)2910 Perl_hv_iternext_flags(pTHX_ HV *hv, I32 flags)
2911 {
2912 HE *entry;
2913 HE *oldentry;
2914 MAGIC* mg;
2915 struct xpvhv_aux *iter;
2916
2917 PERL_ARGS_ASSERT_HV_ITERNEXT_FLAGS;
2918
2919 if (!HvHasAUX(hv)) {
2920 /* Too many things (well, pp_each at least) merrily assume that you can
2921 call hv_iternext without calling hv_iterinit, so we'll have to deal
2922 with it. */
2923 hv_iterinit(hv);
2924 }
2925 else if (!HvARRAY(hv)) {
2926 /* Since 5.002 calling hv_iternext() has ensured that HvARRAY() is
2927 non-NULL. There was explicit code for this added as part of commit
2928 4633a7c4bad06b47, without any explicit comment as to why, but from
2929 code inspection it seems to be a fix to ensure that the later line
2930 entry = ((HE**)xhv->xhv_array)[xhv->xhv_riter];
2931 was accessing a valid address, because that lookup in the loop was
2932 always reached even if the hash had no keys.
2933
2934 That explicit code was removed in 2005 as part of b79f7545f218479c:
2935 Store the xhv_aux structure after the main array.
2936 This reduces the size of HV bodies from 24 to 20 bytes on a 32 bit
2937 build. It has the side effect of defined %symbol_table:: now always
2938 being true. defined %hash is already deprecated.
2939
2940 with a comment and assertion added to note that after the call to
2941 hv_iterinit() HvARRAY() will now always be non-NULL.
2942
2943 In turn, that potential NULL-pointer access within the loop was made
2944 unreachable in 2009 by commit 9eb4ebd1619c0362
2945 In Perl_hv_iternext_flags(), clarify and generalise the empty hash bailout code.
2946
2947 which skipped the entire while loop if the hash had no keys.
2948 (If the hash has any keys, HvARRAY() cannot be NULL.)
2949 Hence the code in hv_iternext_flags() has long been able to handle
2950 HvARRAY() being NULL because no keys are allocated.
2951
2952 Now that we have decoupled the aux structure from HvARRAY(),
2953 HvARRAY() can now be NULL even when SVf_OOK is true (and the aux
2954 struct is allocated and correction initialised).
2955
2956 Is this actually a guarantee that we need to make? We should check
2957 whether anything is actually relying on this, or if we are simply
2958 making work for ourselves.
2959
2960 For now, keep the behaviour as-was - after calling hv_iternext_flags
2961 ensure that HvARRAY() is non-NULL. Many (other) things are changing -
2962 no need to add risk by changing this too. But in the future we should
2963 consider changing hv_iternext_flags() to avoid allocating HvARRAY()
2964 here, and potentially also we avoid allocating HvARRAY()
2965 automatically in hv_auxinit() */
2966
2967 char *array;
2968 Newxz(array, PERL_HV_ARRAY_ALLOC_BYTES(HvMAX(hv) + 1), char);
2969 HvARRAY(hv) = (HE**)array;
2970 }
2971
2972 iter = HvAUX(hv);
2973
2974 oldentry = entry = iter->xhv_eiter; /* HvEITER(hv) */
2975 if (SvMAGICAL(hv) && SvRMAGICAL(hv)) {
2976 if ( ( mg = mg_find((const SV *)hv, PERL_MAGIC_tied) ) ) {
2977 SV * const key = sv_newmortal();
2978 if (entry) {
2979 sv_setsv(key, HeSVKEY_force(entry));
2980 SvREFCNT_dec(HeSVKEY(entry)); /* get rid of previous key */
2981 HeSVKEY_set(entry, NULL);
2982 }
2983 else {
2984 char *k;
2985 HEK *hek;
2986
2987 /* one HE per MAGICAL hash */
2988 iter->xhv_eiter = entry = new_HE(); /* HvEITER(hv) = new_HE() */
2989 HvLAZYDEL_on(hv); /* make sure entry gets freed */
2990 Zero(entry, 1, HE);
2991 Newxz(k, HEK_BASESIZE + sizeof(const SV *), char);
2992 hek = (HEK*)k;
2993 HeKEY_hek(entry) = hek;
2994 HeKLEN(entry) = HEf_SVKEY;
2995 }
2996 magic_nextpack(MUTABLE_SV(hv),mg,key);
2997 if (SvOK(key)) {
2998 /* force key to stay around until next time */
2999 HeSVKEY_set(entry, SvREFCNT_inc_simple_NN(key));
3000 return entry; /* beware, hent_val is not set */
3001 }
3002 SvREFCNT_dec(HeVAL(entry));
3003 Safefree(HeKEY_hek(entry));
3004 del_HE(entry);
3005 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
3006 HvLAZYDEL_off(hv);
3007 return NULL;
3008 }
3009 }
3010 #if defined(DYNAMIC_ENV_FETCH) && defined(VMS) /* set up %ENV for iteration */
3011 if (!entry && SvRMAGICAL((const SV *)hv)
3012 && mg_find((const SV *)hv, PERL_MAGIC_env)) {
3013 prime_env_iter();
3014 }
3015 #endif
3016
3017 /* hv_iterinit now ensures this. */
3018 assert (HvARRAY(hv));
3019
3020 /* At start of hash, entry is NULL. */
3021 if (entry)
3022 {
3023 entry = HeNEXT(entry);
3024 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
3025 /*
3026 * Skip past any placeholders -- don't want to include them in
3027 * any iteration.
3028 */
3029 while (entry && HeVAL(entry) == &PL_sv_placeholder) {
3030 entry = HeNEXT(entry);
3031 }
3032 }
3033 }
3034
3035 #ifdef PERL_HASH_RANDOMIZE_KEYS
3036 if (iter->xhv_last_rand != iter->xhv_rand) {
3037 if (iter->xhv_riter != -1) {
3038 Perl_ck_warner_d(aTHX_ packWARN(WARN_INTERNAL),
3039 "Use of each() on hash after insertion without resetting hash iterator results in undefined behavior"
3040 pTHX__FORMAT
3041 pTHX__VALUE);
3042 }
3043 iter->xhv_last_rand = iter->xhv_rand;
3044 }
3045 #endif
3046
3047 /* Skip the entire loop if the hash is empty. */
3048 if ((flags & HV_ITERNEXT_WANTPLACEHOLDERS)
3049 ? HvTOTALKEYS(hv) : HvUSEDKEYS(hv)) {
3050 STRLEN max = HvMAX(hv);
3051 while (!entry) {
3052 /* OK. Come to the end of the current list. Grab the next one. */
3053
3054 iter->xhv_riter++; /* HvRITER(hv)++ */
3055 if (iter->xhv_riter > (I32)max /* HvRITER(hv) > HvMAX(hv) */) {
3056 /* There is no next one. End of the hash. */
3057 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
3058 #ifdef PERL_HASH_RANDOMIZE_KEYS
3059 iter->xhv_last_rand = iter->xhv_rand; /* reset xhv_last_rand so we can detect inserts during traversal */
3060 #endif
3061 break;
3062 }
3063 entry = (HvARRAY(hv))[ PERL_HASH_ITER_BUCKET(iter) & max ];
3064
3065 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
3066 /* If we have an entry, but it's a placeholder, don't count it.
3067 Try the next. */
3068 while (entry && HeVAL(entry) == &PL_sv_placeholder)
3069 entry = HeNEXT(entry);
3070 }
3071 /* Will loop again if this linked list starts NULL
3072 (for HV_ITERNEXT_WANTPLACEHOLDERS)
3073 or if we run through it and find only placeholders. */
3074 }
3075 }
3076 else {
3077 iter->xhv_riter = -1;
3078 #ifdef PERL_HASH_RANDOMIZE_KEYS
3079 iter->xhv_last_rand = iter->xhv_rand;
3080 #endif
3081 }
3082
3083 if (oldentry && HvLAZYDEL(hv)) { /* was deleted earlier? */
3084 HvLAZYDEL_off(hv);
3085 hv_free_ent(NULL, oldentry);
3086 }
3087
3088 iter->xhv_eiter = entry; /* HvEITER(hv) = entry */
3089 return entry;
3090 }
3091
3092 /*
3093 =for apidoc hv_iterkey
3094
3095 Returns the key from the current position of the hash iterator. See
3096 C<L</hv_iterinit>>.
3097
3098 =cut
3099 */
3100
3101 char *
Perl_hv_iterkey(pTHX_ HE * entry,I32 * retlen)3102 Perl_hv_iterkey(pTHX_ HE *entry, I32 *retlen)
3103 {
3104 PERL_ARGS_ASSERT_HV_ITERKEY;
3105
3106 if (HeKLEN(entry) == HEf_SVKEY) {
3107 STRLEN len;
3108 char * const p = SvPV(HeKEY_sv(entry), len);
3109 *retlen = len;
3110 return p;
3111 }
3112 else {
3113 *retlen = HeKLEN(entry);
3114 return HeKEY(entry);
3115 }
3116 }
3117
3118 /* unlike hv_iterval(), this always returns a mortal copy of the key */
3119 /*
3120 =for apidoc hv_iterkeysv
3121
3122 Returns the key as an C<SV*> from the current position of the hash
3123 iterator. The return value will always be a mortal copy of the key. Also
3124 see C<L</hv_iterinit>>.
3125
3126 =cut
3127 */
3128
3129 SV *
Perl_hv_iterkeysv(pTHX_ HE * entry)3130 Perl_hv_iterkeysv(pTHX_ HE *entry)
3131 {
3132 PERL_ARGS_ASSERT_HV_ITERKEYSV;
3133
3134 return newSVhek_mortal(HeKEY_hek(entry));
3135 }
3136
3137 /*
3138 =for apidoc hv_iterval
3139
3140 Returns the value from the current position of the hash iterator. See
3141 C<L</hv_iterkey>>.
3142
3143 =cut
3144 */
3145
3146 SV *
Perl_hv_iterval(pTHX_ HV * hv,HE * entry)3147 Perl_hv_iterval(pTHX_ HV *hv, HE *entry)
3148 {
3149 PERL_ARGS_ASSERT_HV_ITERVAL;
3150
3151 if (SvRMAGICAL(hv)) {
3152 if (mg_find((const SV *)hv, PERL_MAGIC_tied)) {
3153 SV* const sv = sv_newmortal();
3154 if (HeKLEN(entry) == HEf_SVKEY)
3155 mg_copy(MUTABLE_SV(hv), sv, (char*)HeKEY_sv(entry), HEf_SVKEY);
3156 else
3157 mg_copy(MUTABLE_SV(hv), sv, HeKEY(entry), HeKLEN(entry));
3158 return sv;
3159 }
3160 }
3161 return HeVAL(entry);
3162 }
3163
3164 /*
3165 =for apidoc hv_iternextsv
3166
3167 Performs an C<hv_iternext>, C<hv_iterkey>, and C<hv_iterval> in one
3168 operation.
3169
3170 =cut
3171 */
3172
3173 SV *
Perl_hv_iternextsv(pTHX_ HV * hv,char ** key,I32 * retlen)3174 Perl_hv_iternextsv(pTHX_ HV *hv, char **key, I32 *retlen)
3175 {
3176 HE * const he = hv_iternext_flags(hv, 0);
3177
3178 PERL_ARGS_ASSERT_HV_ITERNEXTSV;
3179
3180 if (!he)
3181 return NULL;
3182 *key = hv_iterkey(he, retlen);
3183 return hv_iterval(hv, he);
3184 }
3185
3186 /*
3187
3188 Now a macro in hv.h
3189
3190 =for apidoc hv_magic
3191
3192 Adds magic to a hash. See C<L</sv_magic>>.
3193
3194 =for apidoc unsharepvn
3195
3196 If no one has access to shared string C<str> with length C<len>, free it.
3197
3198 C<len> and C<hash> must both be valid for C<str>.
3199
3200 =cut
3201 */
3202
3203 void
Perl_unsharepvn(pTHX_ const char * str,I32 len,U32 hash)3204 Perl_unsharepvn(pTHX_ const char *str, I32 len, U32 hash)
3205 {
3206 unshare_hek_or_pvn (NULL, str, len, hash);
3207 }
3208
3209
3210 void
Perl_unshare_hek(pTHX_ HEK * hek)3211 Perl_unshare_hek(pTHX_ HEK *hek)
3212 {
3213 assert(hek);
3214 unshare_hek_or_pvn(hek, NULL, 0, 0);
3215 }
3216
3217 /* possibly free a shared string if no one has access to it
3218 hek if non-NULL takes priority over the other 3, else str, len and hash
3219 are used. If so, len and hash must both be valid for str.
3220 */
3221 STATIC void
S_unshare_hek_or_pvn(pTHX_ const HEK * hek,const char * str,I32 len,U32 hash)3222 S_unshare_hek_or_pvn(pTHX_ const HEK *hek, const char *str, I32 len, U32 hash)
3223 {
3224 HE *entry;
3225 HE **oentry;
3226 bool is_utf8 = FALSE;
3227 int k_flags = 0;
3228 const char * const save = str;
3229 struct shared_he *he = NULL;
3230
3231 if (hek) {
3232 assert((HEK_FLAGS(hek) & HVhek_NOTSHARED) == 0);
3233 /* Find the shared he which is just before us in memory. */
3234 he = (struct shared_he *)(((char *)hek)
3235 - STRUCT_OFFSET(struct shared_he,
3236 shared_he_hek));
3237
3238 /* Assert that the caller passed us a genuine (or at least consistent)
3239 shared hek */
3240 assert (he->shared_he_he.hent_hek == hek);
3241
3242 if (he->shared_he_he.he_valu.hent_refcount - 1) {
3243 --he->shared_he_he.he_valu.hent_refcount;
3244 return;
3245 }
3246
3247 hash = HEK_HASH(hek);
3248 } else if (len < 0) {
3249 STRLEN tmplen = -len;
3250 is_utf8 = TRUE;
3251 /* See the note in hv_fetch(). --jhi */
3252 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
3253 len = tmplen;
3254 if (is_utf8)
3255 k_flags = HVhek_UTF8;
3256 if (str != save)
3257 k_flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
3258 }
3259
3260 /* what follows was the moral equivalent of:
3261 if ((Svp = hv_fetch(PL_strtab, tmpsv, FALSE, hash))) {
3262 if (--*Svp == NULL)
3263 hv_delete(PL_strtab, str, len, G_DISCARD, hash);
3264 } */
3265
3266 /* assert(xhv_array != 0) */
3267 oentry = &(HvARRAY(PL_strtab))[hash & (I32) HvMAX(PL_strtab)];
3268 if (he) {
3269 const HE *const he_he = &(he->shared_he_he);
3270 for (entry = *oentry; entry; oentry = &HeNEXT(entry), entry = *oentry) {
3271 if (entry == he_he)
3272 break;
3273 }
3274 } else {
3275 const U8 flags_masked = k_flags & HVhek_STORAGE_MASK;
3276 for (entry = *oentry; entry; oentry = &HeNEXT(entry), entry = *oentry) {
3277 if (HeHASH(entry) != hash) /* strings can't be equal */
3278 continue;
3279 if (HeKLEN(entry) != len)
3280 continue;
3281 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
3282 continue;
3283 if (HeKFLAGS(entry) != flags_masked)
3284 continue;
3285 break;
3286 }
3287 }
3288
3289 if (entry) {
3290 if (--entry->he_valu.hent_refcount == 0) {
3291 *oentry = HeNEXT(entry);
3292 Safefree(entry);
3293 HvTOTALKEYS(PL_strtab)--;
3294 }
3295 }
3296
3297 if (!entry)
3298 Perl_ck_warner_d(aTHX_ packWARN(WARN_INTERNAL),
3299 "Attempt to free nonexistent shared string '%s'%s"
3300 pTHX__FORMAT,
3301 hek ? HEK_KEY(hek) : str,
3302 ((k_flags & HVhek_UTF8) ? " (utf8)" : "") pTHX__VALUE);
3303 if (k_flags & HVhek_FREEKEY)
3304 Safefree(str);
3305 }
3306
3307 /* get a (constant) string ptr from the global string table
3308 * string will get added if it is not already there.
3309 * len and hash must both be valid for str.
3310 */
3311 HEK *
Perl_share_hek(pTHX_ const char * str,SSize_t len,U32 hash)3312 Perl_share_hek(pTHX_ const char *str, SSize_t len, U32 hash)
3313 {
3314 bool is_utf8 = FALSE;
3315 int flags = 0;
3316 const char * const save = str;
3317
3318 PERL_ARGS_ASSERT_SHARE_HEK;
3319
3320 if (len < 0) {
3321 STRLEN tmplen = -len;
3322 is_utf8 = TRUE;
3323 /* See the note in hv_fetch(). --jhi */
3324 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
3325 len = tmplen;
3326 /* If we were able to downgrade here, then than means that we were passed
3327 in a key which only had chars 0-255, but was utf8 encoded. */
3328 if (is_utf8)
3329 flags = HVhek_UTF8;
3330 /* If we found we were able to downgrade the string to bytes, then
3331 we should flag that it needs upgrading on keys or each. Also flag
3332 that we need share_hek_flags to free the string. */
3333 if (str != save) {
3334 PERL_HASH(hash, str, len);
3335 flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
3336 }
3337 }
3338
3339 return share_hek_flags (str, len, hash, flags);
3340 }
3341
3342 STATIC HEK *
S_share_hek_flags(pTHX_ const char * str,STRLEN len,U32 hash,int flags)3343 S_share_hek_flags(pTHX_ const char *str, STRLEN len, U32 hash, int flags)
3344 {
3345 HE *entry;
3346 const U8 flags_masked = flags & HVhek_STORAGE_MASK;
3347 const U32 hindex = hash & (I32) HvMAX(PL_strtab);
3348
3349 PERL_ARGS_ASSERT_SHARE_HEK_FLAGS;
3350 assert(!(flags & HVhek_NOTSHARED));
3351
3352 if (UNLIKELY(len > (STRLEN) I32_MAX)) {
3353 Perl_croak_nocontext("Sorry, hash keys must be smaller than 2**31 bytes");
3354 }
3355
3356 /* what follows is the moral equivalent of:
3357
3358 if (!(Svp = hv_fetch(PL_strtab, str, len, FALSE)))
3359 hv_store(PL_strtab, str, len, NULL, hash);
3360
3361 Can't rehash the shared string table, so not sure if it's worth
3362 counting the number of entries in the linked list
3363 */
3364
3365 /* assert(xhv_array != 0) */
3366 entry = (HvARRAY(PL_strtab))[hindex];
3367 for (;entry; entry = HeNEXT(entry)) {
3368 if (HeHASH(entry) != hash) /* strings can't be equal */
3369 continue;
3370 if (HeKLEN(entry) != (SSize_t) len)
3371 continue;
3372 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
3373 continue;
3374 if (HeKFLAGS(entry) != flags_masked)
3375 continue;
3376 break;
3377 }
3378
3379 if (!entry) {
3380 /* What used to be head of the list.
3381 If this is NULL, then we're the first entry for this slot, which
3382 means we need to increase fill. */
3383 struct shared_he *new_entry;
3384 HEK *hek;
3385 char *k;
3386 HE **const head = &HvARRAY(PL_strtab)[hindex];
3387 HE *const next = *head;
3388 XPVHV * const xhv = (XPVHV*)SvANY(PL_strtab);
3389
3390 /* We don't actually store a HE from the arena and a regular HEK.
3391 Instead we allocate one chunk of memory big enough for both,
3392 and put the HEK straight after the HE. This way we can find the
3393 HE directly from the HEK.
3394 */
3395
3396 Newx(k, STRUCT_OFFSET(struct shared_he,
3397 shared_he_hek.hek_key[0]) + len + 2, char);
3398 new_entry = (struct shared_he *)k;
3399 entry = &(new_entry->shared_he_he);
3400 hek = &(new_entry->shared_he_hek);
3401
3402 Copy(str, HEK_KEY(hek), len, char);
3403 HEK_KEY(hek)[len] = 0;
3404 HEK_LEN(hek) = len;
3405 HEK_HASH(hek) = hash;
3406 HEK_FLAGS(hek) = (unsigned char)flags_masked;
3407
3408 /* Still "point" to the HEK, so that other code need not know what
3409 we're up to. */
3410 HeKEY_hek(entry) = hek;
3411 entry->he_valu.hent_refcount = 0;
3412 HeNEXT(entry) = next;
3413 *head = entry;
3414
3415 xhv->xhv_keys++; /* HvTOTALKEYS(hv)++ */
3416 if (!next) { /* initial entry? */
3417 } else if ( DO_HSPLIT(xhv) ) {
3418 const STRLEN oldsize = xhv->xhv_max + 1;
3419 hsplit(PL_strtab, oldsize, oldsize * 2);
3420 }
3421 }
3422
3423 ++entry->he_valu.hent_refcount;
3424
3425 if (flags & HVhek_FREEKEY)
3426 Safefree(str);
3427
3428 return HeKEY_hek(entry);
3429 }
3430
3431 SSize_t *
Perl_hv_placeholders_p(pTHX_ HV * hv)3432 Perl_hv_placeholders_p(pTHX_ HV *hv)
3433 {
3434 MAGIC *mg = mg_find((const SV *)hv, PERL_MAGIC_rhash);
3435
3436 PERL_ARGS_ASSERT_HV_PLACEHOLDERS_P;
3437
3438 if (!mg) {
3439 mg = sv_magicext(MUTABLE_SV(hv), 0, PERL_MAGIC_rhash, 0, 0, 0);
3440
3441 if (!mg) {
3442 Perl_die(aTHX_ "panic: hv_placeholders_p");
3443 }
3444 }
3445 return &(mg->mg_len);
3446 }
3447
3448 /*
3449 =for apidoc hv_placeholders_get
3450
3451 Implements C<HvPLACEHOLDERS_get>, which you should use instead.
3452
3453 =cut
3454 */
3455
3456 I32
Perl_hv_placeholders_get(pTHX_ const HV * hv)3457 Perl_hv_placeholders_get(pTHX_ const HV *hv)
3458 {
3459 MAGIC * const mg = mg_find((const SV *)hv, PERL_MAGIC_rhash);
3460
3461 PERL_ARGS_ASSERT_HV_PLACEHOLDERS_GET;
3462 PERL_UNUSED_CONTEXT;
3463
3464 return mg ? mg->mg_len : 0;
3465 }
3466
3467 /*
3468 =for apidoc hv_placeholders_set
3469
3470 Implements C<HvPLACEHOLDERS_set>, which you should use instead.
3471
3472 =cut
3473 */
3474
3475 void
Perl_hv_placeholders_set(pTHX_ HV * hv,I32 ph)3476 Perl_hv_placeholders_set(pTHX_ HV *hv, I32 ph)
3477 {
3478 MAGIC * const mg = mg_find((const SV *)hv, PERL_MAGIC_rhash);
3479
3480 PERL_ARGS_ASSERT_HV_PLACEHOLDERS_SET;
3481
3482 if (mg) {
3483 mg->mg_len = ph;
3484 } else if (ph) {
3485 if (!sv_magicext(MUTABLE_SV(hv), 0, PERL_MAGIC_rhash, 0, 0, ph))
3486 Perl_die(aTHX_ "panic: hv_placeholders_set");
3487 }
3488 /* else we don't need to add magic to record 0 placeholders. */
3489 }
3490
3491 STATIC SV *
S_refcounted_he_value(pTHX_ const struct refcounted_he * he)3492 S_refcounted_he_value(pTHX_ const struct refcounted_he *he)
3493 {
3494 SV *value;
3495
3496 PERL_ARGS_ASSERT_REFCOUNTED_HE_VALUE;
3497
3498 switch(he->refcounted_he_data[0] & HVrhek_typemask) {
3499 case HVrhek_undef:
3500 value = newSV_type(SVt_NULL);
3501 break;
3502 case HVrhek_delete:
3503 value = &PL_sv_placeholder;
3504 break;
3505 case HVrhek_IV:
3506 value = newSViv(he->refcounted_he_val.refcounted_he_u_iv);
3507 break;
3508 case HVrhek_UV:
3509 value = newSVuv(he->refcounted_he_val.refcounted_he_u_uv);
3510 break;
3511 case HVrhek_PV:
3512 case HVrhek_PV_UTF8:
3513 /* Create a string SV that directly points to the bytes in our
3514 structure. */
3515 value = newSV_type(SVt_PV);
3516 SvPV_set(value, (char *) he->refcounted_he_data + 1);
3517 SvCUR_set(value, he->refcounted_he_val.refcounted_he_u_len);
3518 /* This stops anything trying to free it */
3519 SvLEN_set(value, 0);
3520 SvPOK_on(value);
3521 SvREADONLY_on(value);
3522 if ((he->refcounted_he_data[0] & HVrhek_typemask) == HVrhek_PV_UTF8)
3523 SvUTF8_on(value);
3524 break;
3525 default:
3526 Perl_croak(aTHX_ "panic: refcounted_he_value bad flags %" UVxf,
3527 (UV)he->refcounted_he_data[0]);
3528 }
3529 return value;
3530 }
3531
3532 /*
3533 =for apidoc refcounted_he_chain_2hv
3534
3535 Generates and returns a C<HV *> representing the content of a
3536 C<refcounted_he> chain.
3537 C<flags> is currently unused and must be zero.
3538
3539 =cut
3540 */
3541 HV *
Perl_refcounted_he_chain_2hv(pTHX_ const struct refcounted_he * chain,U32 flags)3542 Perl_refcounted_he_chain_2hv(pTHX_ const struct refcounted_he *chain, U32 flags)
3543 {
3544 HV *hv;
3545 U32 placeholders, max;
3546
3547 if (flags)
3548 Perl_croak(aTHX_ "panic: refcounted_he_chain_2hv bad flags %" UVxf,
3549 (UV)flags);
3550
3551 /* We could chase the chain once to get an idea of the number of keys,
3552 and call ksplit. But for now we'll make a potentially inefficient
3553 hash with only 8 entries in its array. */
3554 hv = newHV();
3555 #ifdef NODEFAULT_SHAREKEYS
3556 /* We share keys in the COP, so it's much easier to keep sharing keys in
3557 the hash we build from it. */
3558 HvSHAREKEYS_on(hv);
3559 #endif
3560 max = HvMAX(hv);
3561 if (!HvARRAY(hv)) {
3562 char *array;
3563 Newxz(array, PERL_HV_ARRAY_ALLOC_BYTES(max + 1), char);
3564 HvARRAY(hv) = (HE**)array;
3565 }
3566
3567 placeholders = 0;
3568 while (chain) {
3569 #ifdef USE_ITHREADS
3570 U32 hash = chain->refcounted_he_hash;
3571 #else
3572 U32 hash = HEK_HASH(chain->refcounted_he_hek);
3573 #endif
3574 HE **oentry = &((HvARRAY(hv))[hash & max]);
3575 HE *entry = *oentry;
3576 SV *value;
3577
3578 for (; entry; entry = HeNEXT(entry)) {
3579 if (HeHASH(entry) == hash) {
3580 /* We might have a duplicate key here. If so, entry is older
3581 than the key we've already put in the hash, so if they are
3582 the same, skip adding entry. */
3583 #ifdef USE_ITHREADS
3584 const STRLEN klen = HeKLEN(entry);
3585 const char *const key = HeKEY(entry);
3586 if (klen == chain->refcounted_he_keylen
3587 && (cBOOL(HeKUTF8(entry))
3588 == cBOOL((chain->refcounted_he_data[0] & HVhek_UTF8)))
3589 && memEQ(key, REF_HE_KEY(chain), klen))
3590 goto next_please;
3591 #else
3592 if (HeKEY_hek(entry) == chain->refcounted_he_hek)
3593 goto next_please;
3594 if (HeKLEN(entry) == HEK_LEN(chain->refcounted_he_hek)
3595 && HeKUTF8(entry) == HEK_UTF8(chain->refcounted_he_hek)
3596 && memEQ(HeKEY(entry), HEK_KEY(chain->refcounted_he_hek),
3597 HeKLEN(entry)))
3598 goto next_please;
3599 #endif
3600 }
3601 }
3602 assert (!entry);
3603 entry = new_HE();
3604
3605 #ifdef USE_ITHREADS
3606 HeKEY_hek(entry)
3607 = share_hek_flags(REF_HE_KEY(chain),
3608 chain->refcounted_he_keylen,
3609 chain->refcounted_he_hash,
3610 (chain->refcounted_he_data[0]
3611 & (HVhek_UTF8|HVhek_WASUTF8)));
3612 #else
3613 HeKEY_hek(entry) = share_hek_hek(chain->refcounted_he_hek);
3614 #endif
3615 value = refcounted_he_value(chain);
3616 if (value == &PL_sv_placeholder)
3617 placeholders++;
3618 HeVAL(entry) = value;
3619
3620 /* Link it into the chain. */
3621 HeNEXT(entry) = *oentry;
3622 *oentry = entry;
3623
3624 HvTOTALKEYS(hv)++;
3625
3626 next_please:
3627 chain = chain->refcounted_he_next;
3628 }
3629
3630 if (placeholders) {
3631 clear_placeholders(hv, placeholders);
3632 }
3633
3634 /* We could check in the loop to see if we encounter any keys with key
3635 flags, but it's probably not worth it, as this per-hash flag is only
3636 really meant as an optimisation for things like Storable. */
3637 HvHASKFLAGS_on(hv);
3638 DEBUG_A(Perl_hv_assert(aTHX_ hv));
3639
3640 return hv;
3641 }
3642
3643 /*
3644 =for apidoc refcounted_he_fetch_pvn
3645
3646 Search along a C<refcounted_he> chain for an entry with the key specified
3647 by C<keypv> and C<keylen>. If C<flags> has the C<REFCOUNTED_HE_KEY_UTF8>
3648 bit set, the key octets are interpreted as UTF-8, otherwise they
3649 are interpreted as Latin-1. C<hash> is a precomputed hash of the key
3650 string, or zero if it has not been precomputed. Returns a mortal scalar
3651 representing the value associated with the key, or C<&PL_sv_placeholder>
3652 if there is no value associated with the key.
3653
3654 =cut
3655 */
3656
3657 SV *
Perl_refcounted_he_fetch_pvn(pTHX_ const struct refcounted_he * chain,const char * keypv,STRLEN keylen,U32 hash,U32 flags)3658 Perl_refcounted_he_fetch_pvn(pTHX_ const struct refcounted_he *chain,
3659 const char *keypv, STRLEN keylen, U32 hash, U32 flags)
3660 {
3661 U8 utf8_flag;
3662 PERL_ARGS_ASSERT_REFCOUNTED_HE_FETCH_PVN;
3663
3664 if (flags & ~(REFCOUNTED_HE_KEY_UTF8|REFCOUNTED_HE_EXISTS))
3665 Perl_croak(aTHX_ "panic: refcounted_he_fetch_pvn bad flags %" UVxf,
3666 (UV)flags);
3667 if (!chain)
3668 goto ret;
3669 if (flags & REFCOUNTED_HE_KEY_UTF8) {
3670 /* For searching purposes, canonicalise to Latin-1 where possible. */
3671 const char *keyend = keypv + keylen, *p;
3672 STRLEN nonascii_count = 0;
3673 for (p = keypv; p != keyend; p++) {
3674 if (! UTF8_IS_INVARIANT(*p)) {
3675 if (! UTF8_IS_NEXT_CHAR_DOWNGRADEABLE(p, keyend)) {
3676 goto canonicalised_key;
3677 }
3678 nonascii_count++;
3679 p++;
3680 }
3681 }
3682 if (nonascii_count) {
3683 char *q;
3684 const char *p = keypv, *keyend = keypv + keylen;
3685 keylen -= nonascii_count;
3686 Newx(q, keylen, char);
3687 SAVEFREEPV(q);
3688 keypv = q;
3689 for (; p != keyend; p++, q++) {
3690 U8 c = (U8)*p;
3691 if (UTF8_IS_INVARIANT(c)) {
3692 *q = (char) c;
3693 }
3694 else {
3695 p++;
3696 *q = (char) EIGHT_BIT_UTF8_TO_NATIVE(c, *p);
3697 }
3698 }
3699 }
3700 flags &= ~REFCOUNTED_HE_KEY_UTF8;
3701 canonicalised_key: ;
3702 }
3703 utf8_flag = (flags & REFCOUNTED_HE_KEY_UTF8) ? HVhek_UTF8 : 0;
3704 if (!hash)
3705 PERL_HASH(hash, keypv, keylen);
3706
3707 for (; chain; chain = chain->refcounted_he_next) {
3708 if (
3709 #ifdef USE_ITHREADS
3710 hash == chain->refcounted_he_hash &&
3711 keylen == chain->refcounted_he_keylen &&
3712 memEQ(REF_HE_KEY(chain), keypv, keylen) &&
3713 utf8_flag == (chain->refcounted_he_data[0] & HVhek_UTF8)
3714 #else
3715 hash == HEK_HASH(chain->refcounted_he_hek) &&
3716 keylen == (STRLEN)HEK_LEN(chain->refcounted_he_hek) &&
3717 memEQ(HEK_KEY(chain->refcounted_he_hek), keypv, keylen) &&
3718 utf8_flag == (HEK_FLAGS(chain->refcounted_he_hek) & HVhek_UTF8)
3719 #endif
3720 ) {
3721 if (flags & REFCOUNTED_HE_EXISTS)
3722 return (chain->refcounted_he_data[0] & HVrhek_typemask)
3723 == HVrhek_delete
3724 ? NULL : &PL_sv_yes;
3725 return sv_2mortal(refcounted_he_value(chain));
3726 }
3727 }
3728 ret:
3729 return flags & REFCOUNTED_HE_EXISTS ? NULL : &PL_sv_placeholder;
3730 }
3731
3732 /*
3733 =for apidoc refcounted_he_fetch_pv
3734
3735 Like L</refcounted_he_fetch_pvn>, but takes a nul-terminated string
3736 instead of a string/length pair.
3737
3738 =cut
3739 */
3740
3741 SV *
Perl_refcounted_he_fetch_pv(pTHX_ const struct refcounted_he * chain,const char * key,U32 hash,U32 flags)3742 Perl_refcounted_he_fetch_pv(pTHX_ const struct refcounted_he *chain,
3743 const char *key, U32 hash, U32 flags)
3744 {
3745 PERL_ARGS_ASSERT_REFCOUNTED_HE_FETCH_PV;
3746 return refcounted_he_fetch_pvn(chain, key, strlen(key), hash, flags);
3747 }
3748
3749 /*
3750 =for apidoc refcounted_he_fetch_sv
3751
3752 Like L</refcounted_he_fetch_pvn>, but takes a Perl scalar instead of a
3753 string/length pair.
3754
3755 =cut
3756 */
3757
3758 SV *
Perl_refcounted_he_fetch_sv(pTHX_ const struct refcounted_he * chain,SV * key,U32 hash,U32 flags)3759 Perl_refcounted_he_fetch_sv(pTHX_ const struct refcounted_he *chain,
3760 SV *key, U32 hash, U32 flags)
3761 {
3762 const char *keypv;
3763 STRLEN keylen;
3764 PERL_ARGS_ASSERT_REFCOUNTED_HE_FETCH_SV;
3765 if (flags & REFCOUNTED_HE_KEY_UTF8)
3766 Perl_croak(aTHX_ "panic: refcounted_he_fetch_sv bad flags %" UVxf,
3767 (UV)flags);
3768 keypv = SvPV_const(key, keylen);
3769 if (SvUTF8(key))
3770 flags |= REFCOUNTED_HE_KEY_UTF8;
3771 if (!hash && SvIsCOW_shared_hash(key))
3772 hash = SvSHARED_HASH(key);
3773 return refcounted_he_fetch_pvn(chain, keypv, keylen, hash, flags);
3774 }
3775
3776 /*
3777 =for apidoc refcounted_he_new_pvn
3778
3779 Creates a new C<refcounted_he>. This consists of a single key/value
3780 pair and a reference to an existing C<refcounted_he> chain (which may
3781 be empty), and thus forms a longer chain. When using the longer chain,
3782 the new key/value pair takes precedence over any entry for the same key
3783 further along the chain.
3784
3785 The new key is specified by C<keypv> and C<keylen>. If C<flags> has
3786 the C<REFCOUNTED_HE_KEY_UTF8> bit set, the key octets are interpreted
3787 as UTF-8, otherwise they are interpreted as Latin-1. C<hash> is
3788 a precomputed hash of the key string, or zero if it has not been
3789 precomputed.
3790
3791 C<value> is the scalar value to store for this key. C<value> is copied
3792 by this function, which thus does not take ownership of any reference
3793 to it, and later changes to the scalar will not be reflected in the
3794 value visible in the C<refcounted_he>. Complex types of scalar will not
3795 be stored with referential integrity, but will be coerced to strings.
3796 C<value> may be either null or C<&PL_sv_placeholder> to indicate that no
3797 value is to be associated with the key; this, as with any non-null value,
3798 takes precedence over the existence of a value for the key further along
3799 the chain.
3800
3801 C<parent> points to the rest of the C<refcounted_he> chain to be
3802 attached to the new C<refcounted_he>. This function takes ownership
3803 of one reference to C<parent>, and returns one reference to the new
3804 C<refcounted_he>.
3805
3806 =cut
3807 */
3808
3809 struct refcounted_he *
Perl_refcounted_he_new_pvn(pTHX_ struct refcounted_he * parent,const char * keypv,STRLEN keylen,U32 hash,SV * value,U32 flags)3810 Perl_refcounted_he_new_pvn(pTHX_ struct refcounted_he *parent,
3811 const char *keypv, STRLEN keylen, U32 hash, SV *value, U32 flags)
3812 {
3813 STRLEN value_len = 0;
3814 const char *value_p = NULL;
3815 bool is_pv;
3816 char value_type;
3817 char hekflags;
3818 STRLEN key_offset = 1;
3819 struct refcounted_he *he;
3820 PERL_ARGS_ASSERT_REFCOUNTED_HE_NEW_PVN;
3821
3822 if (!value || value == &PL_sv_placeholder) {
3823 value_type = HVrhek_delete;
3824 } else if (SvPOK(value)) {
3825 value_type = HVrhek_PV;
3826 } else if (SvIOK(value)) {
3827 value_type = SvUOK((const SV *)value) ? HVrhek_UV : HVrhek_IV;
3828 } else if (!SvOK(value)) {
3829 value_type = HVrhek_undef;
3830 } else {
3831 value_type = HVrhek_PV;
3832 }
3833 is_pv = value_type == HVrhek_PV;
3834 if (is_pv) {
3835 /* Do it this way so that the SvUTF8() test is after the SvPV, in case
3836 the value is overloaded, and doesn't yet have the UTF-8flag set. */
3837 value_p = SvPV_const(value, value_len);
3838 if (SvUTF8(value))
3839 value_type = HVrhek_PV_UTF8;
3840 key_offset = value_len + 2;
3841 }
3842 hekflags = value_type;
3843
3844 if (flags & REFCOUNTED_HE_KEY_UTF8) {
3845 /* Canonicalise to Latin-1 where possible. */
3846 const char *keyend = keypv + keylen, *p;
3847 STRLEN nonascii_count = 0;
3848 for (p = keypv; p != keyend; p++) {
3849 if (! UTF8_IS_INVARIANT(*p)) {
3850 if (! UTF8_IS_NEXT_CHAR_DOWNGRADEABLE(p, keyend)) {
3851 goto canonicalised_key;
3852 }
3853 nonascii_count++;
3854 p++;
3855 }
3856 }
3857 if (nonascii_count) {
3858 char *q;
3859 const char *p = keypv, *keyend = keypv + keylen;
3860 keylen -= nonascii_count;
3861 Newx(q, keylen, char);
3862 SAVEFREEPV(q);
3863 keypv = q;
3864 for (; p != keyend; p++, q++) {
3865 U8 c = (U8)*p;
3866 if (UTF8_IS_INVARIANT(c)) {
3867 *q = (char) c;
3868 }
3869 else {
3870 p++;
3871 *q = (char) EIGHT_BIT_UTF8_TO_NATIVE(c, *p);
3872 }
3873 }
3874 }
3875 flags &= ~REFCOUNTED_HE_KEY_UTF8;
3876 canonicalised_key: ;
3877 }
3878 if (flags & REFCOUNTED_HE_KEY_UTF8)
3879 hekflags |= HVhek_UTF8;
3880 if (!hash)
3881 PERL_HASH(hash, keypv, keylen);
3882
3883 #ifdef USE_ITHREADS
3884 he = (struct refcounted_he*)
3885 PerlMemShared_malloc(sizeof(struct refcounted_he) - 1
3886 + keylen
3887 + key_offset);
3888 #else
3889 he = (struct refcounted_he*)
3890 PerlMemShared_malloc(sizeof(struct refcounted_he) - 1
3891 + key_offset);
3892 #endif
3893
3894 he->refcounted_he_next = parent;
3895
3896 if (is_pv) {
3897 Copy(value_p, he->refcounted_he_data + 1, value_len + 1, char);
3898 he->refcounted_he_val.refcounted_he_u_len = value_len;
3899 } else if (value_type == HVrhek_IV) {
3900 he->refcounted_he_val.refcounted_he_u_iv = SvIVX(value);
3901 } else if (value_type == HVrhek_UV) {
3902 he->refcounted_he_val.refcounted_he_u_uv = SvUVX(value);
3903 }
3904
3905 #ifdef USE_ITHREADS
3906 he->refcounted_he_hash = hash;
3907 he->refcounted_he_keylen = keylen;
3908 Copy(keypv, he->refcounted_he_data + key_offset, keylen, char);
3909 #else
3910 he->refcounted_he_hek = share_hek_flags(keypv, keylen, hash, hekflags);
3911 #endif
3912
3913 he->refcounted_he_data[0] = hekflags;
3914 he->refcounted_he_refcnt = 1;
3915
3916 return he;
3917 }
3918
3919 /*
3920 =for apidoc refcounted_he_new_pv
3921
3922 Like L</refcounted_he_new_pvn>, but takes a nul-terminated string instead
3923 of a string/length pair.
3924
3925 =cut
3926 */
3927
3928 struct refcounted_he *
Perl_refcounted_he_new_pv(pTHX_ struct refcounted_he * parent,const char * key,U32 hash,SV * value,U32 flags)3929 Perl_refcounted_he_new_pv(pTHX_ struct refcounted_he *parent,
3930 const char *key, U32 hash, SV *value, U32 flags)
3931 {
3932 PERL_ARGS_ASSERT_REFCOUNTED_HE_NEW_PV;
3933 return refcounted_he_new_pvn(parent, key, strlen(key), hash, value, flags);
3934 }
3935
3936 /*
3937 =for apidoc refcounted_he_new_sv
3938
3939 Like L</refcounted_he_new_pvn>, but takes a Perl scalar instead of a
3940 string/length pair.
3941
3942 =cut
3943 */
3944
3945 struct refcounted_he *
Perl_refcounted_he_new_sv(pTHX_ struct refcounted_he * parent,SV * key,U32 hash,SV * value,U32 flags)3946 Perl_refcounted_he_new_sv(pTHX_ struct refcounted_he *parent,
3947 SV *key, U32 hash, SV *value, U32 flags)
3948 {
3949 const char *keypv;
3950 STRLEN keylen;
3951 PERL_ARGS_ASSERT_REFCOUNTED_HE_NEW_SV;
3952 if (flags & REFCOUNTED_HE_KEY_UTF8)
3953 Perl_croak(aTHX_ "panic: refcounted_he_new_sv bad flags %" UVxf,
3954 (UV)flags);
3955 keypv = SvPV_const(key, keylen);
3956 if (SvUTF8(key))
3957 flags |= REFCOUNTED_HE_KEY_UTF8;
3958 if (!hash && SvIsCOW_shared_hash(key))
3959 hash = SvSHARED_HASH(key);
3960 return refcounted_he_new_pvn(parent, keypv, keylen, hash, value, flags);
3961 }
3962
3963 /*
3964 =for apidoc refcounted_he_free
3965
3966 Decrements the reference count of a C<refcounted_he> by one. If the
3967 reference count reaches zero the structure's memory is freed, which
3968 (recursively) causes a reduction of its parent C<refcounted_he>'s
3969 reference count. It is safe to pass a null pointer to this function:
3970 no action occurs in this case.
3971
3972 =cut
3973 */
3974
3975 void
Perl_refcounted_he_free(pTHX_ struct refcounted_he * he)3976 Perl_refcounted_he_free(pTHX_ struct refcounted_he *he) {
3977 PERL_UNUSED_CONTEXT;
3978
3979 while (he) {
3980 struct refcounted_he *copy;
3981 U32 new_count;
3982
3983 HINTS_REFCNT_LOCK;
3984 new_count = --he->refcounted_he_refcnt;
3985 HINTS_REFCNT_UNLOCK;
3986
3987 if (new_count) {
3988 return;
3989 }
3990
3991 #ifndef USE_ITHREADS
3992 unshare_hek_or_pvn (he->refcounted_he_hek, 0, 0, 0);
3993 #endif
3994 copy = he;
3995 he = he->refcounted_he_next;
3996 PerlMemShared_free(copy);
3997 }
3998 }
3999
4000 /*
4001 =for apidoc refcounted_he_inc
4002
4003 Increment the reference count of a C<refcounted_he>. The pointer to the
4004 C<refcounted_he> is also returned. It is safe to pass a null pointer
4005 to this function: no action occurs and a null pointer is returned.
4006
4007 =cut
4008 */
4009
4010 struct refcounted_he *
Perl_refcounted_he_inc(pTHX_ struct refcounted_he * he)4011 Perl_refcounted_he_inc(pTHX_ struct refcounted_he *he)
4012 {
4013 PERL_UNUSED_CONTEXT;
4014 if (he) {
4015 HINTS_REFCNT_LOCK;
4016 he->refcounted_he_refcnt++;
4017 HINTS_REFCNT_UNLOCK;
4018 }
4019 return he;
4020 }
4021
4022 /*
4023 =for apidoc_section $COP
4024 =for apidoc cop_fetch_label
4025
4026 Returns the label attached to a cop, and stores its length in bytes into
4027 C<*len>.
4028 Upon return, C<*flags> will be set to either C<SVf_UTF8> or 0.
4029
4030 Alternatively, use the macro C<L</CopLABEL_len_flags>>;
4031 or if you don't need to know if the label is UTF-8 or not, the macro
4032 C<L</CopLABEL_len>>;
4033 or if you additionally don't need to know the length, C<L</CopLABEL>>.
4034
4035 =cut
4036 */
4037
4038 /* pp_entereval is aware that labels are stored with a key ':' at the top of
4039 the linked list. */
4040 const char *
Perl_cop_fetch_label(pTHX_ COP * const cop,STRLEN * len,U32 * flags)4041 Perl_cop_fetch_label(pTHX_ COP *const cop, STRLEN *len, U32 *flags) {
4042 struct refcounted_he *const chain = cop->cop_hints_hash;
4043
4044 PERL_ARGS_ASSERT_COP_FETCH_LABEL;
4045 PERL_UNUSED_CONTEXT;
4046
4047 if (!chain)
4048 return NULL;
4049 #ifdef USE_ITHREADS
4050 if (chain->refcounted_he_keylen != 1)
4051 return NULL;
4052 if (*REF_HE_KEY(chain) != ':')
4053 return NULL;
4054 #else
4055 if ((STRLEN)HEK_LEN(chain->refcounted_he_hek) != 1)
4056 return NULL;
4057 if (*HEK_KEY(chain->refcounted_he_hek) != ':')
4058 return NULL;
4059 #endif
4060 /* Stop anyone trying to really mess us up by adding their own value for
4061 ':' into %^H */
4062 if ((chain->refcounted_he_data[0] & HVrhek_typemask) != HVrhek_PV
4063 && (chain->refcounted_he_data[0] & HVrhek_typemask) != HVrhek_PV_UTF8)
4064 return NULL;
4065
4066 if (len)
4067 *len = chain->refcounted_he_val.refcounted_he_u_len;
4068 if (flags) {
4069 *flags = ((chain->refcounted_he_data[0] & HVrhek_typemask)
4070 == HVrhek_PV_UTF8) ? SVf_UTF8 : 0;
4071 }
4072 return chain->refcounted_he_data + 1;
4073 }
4074
4075 /*
4076 =for apidoc cop_store_label
4077
4078 Save a label into a C<cop_hints_hash>.
4079 You need to set flags to C<SVf_UTF8>
4080 for a UTF-8 label. Any other flag is ignored.
4081
4082 =cut
4083 */
4084
4085 void
Perl_cop_store_label(pTHX_ COP * const cop,const char * label,STRLEN len,U32 flags)4086 Perl_cop_store_label(pTHX_ COP *const cop, const char *label, STRLEN len,
4087 U32 flags)
4088 {
4089 SV *labelsv;
4090 PERL_ARGS_ASSERT_COP_STORE_LABEL;
4091
4092 if (flags & ~(SVf_UTF8))
4093 Perl_croak(aTHX_ "panic: cop_store_label illegal flag bits 0x%" UVxf,
4094 (UV)flags);
4095 labelsv = newSVpvn_flags(label, len, SVs_TEMP);
4096 if (flags & SVf_UTF8)
4097 SvUTF8_on(labelsv);
4098 cop->cop_hints_hash
4099 = refcounted_he_new_pvs(cop->cop_hints_hash, ":", labelsv, 0);
4100 }
4101
4102 /*
4103 =for apidoc_section $HV
4104 =for apidoc hv_assert
4105
4106 Check that a hash is in an internally consistent state.
4107
4108 =cut
4109 */
4110
4111 #ifdef DEBUGGING
4112
4113 void
Perl_hv_assert(pTHX_ HV * hv)4114 Perl_hv_assert(pTHX_ HV *hv)
4115 {
4116 HE* entry;
4117 int withflags = 0;
4118 int placeholders = 0;
4119 int real = 0;
4120 int bad = 0;
4121 const I32 riter = HvRITER_get(hv);
4122 HE *eiter = HvEITER_get(hv);
4123
4124 PERL_ARGS_ASSERT_HV_ASSERT;
4125
4126 (void)hv_iterinit(hv);
4127
4128 while ((entry = hv_iternext_flags(hv, HV_ITERNEXT_WANTPLACEHOLDERS))) {
4129 /* sanity check the values */
4130 if (HeVAL(entry) == &PL_sv_placeholder)
4131 placeholders++;
4132 else
4133 real++;
4134 /* sanity check the keys */
4135 if (HeSVKEY(entry)) {
4136 NOOP; /* Don't know what to check on SV keys. */
4137 } else if (HeKUTF8(entry)) {
4138 withflags++;
4139 if (HeKWASUTF8(entry)) {
4140 PerlIO_printf(Perl_debug_log,
4141 "hash key has both WASUTF8 and UTF8: '%.*s'\n",
4142 (int) HeKLEN(entry), HeKEY(entry));
4143 bad = 1;
4144 }
4145 } else if (HeKWASUTF8(entry))
4146 withflags++;
4147 }
4148 if (!SvTIED_mg((const SV *)hv, PERL_MAGIC_tied)) {
4149 static const char bad_count[] = "Count %d %s(s), but hash reports %d\n";
4150 const int nhashkeys = HvUSEDKEYS(hv);
4151 const int nhashplaceholders = HvPLACEHOLDERS_get(hv);
4152
4153 if (nhashkeys != real) {
4154 PerlIO_printf(Perl_debug_log, bad_count, real, "keys", nhashkeys );
4155 bad = 1;
4156 }
4157 if (nhashplaceholders != placeholders) {
4158 PerlIO_printf(Perl_debug_log, bad_count, placeholders, "placeholder", nhashplaceholders );
4159 bad = 1;
4160 }
4161 }
4162 if (withflags && ! HvHASKFLAGS(hv)) {
4163 PerlIO_printf(Perl_debug_log,
4164 "Hash has HASKFLAGS off but I count %d key(s) with flags\n",
4165 withflags);
4166 bad = 1;
4167 }
4168 if (bad) {
4169 sv_dump(MUTABLE_SV(hv));
4170 }
4171 HvRITER_set(hv, riter); /* Restore hash iterator state */
4172 HvEITER_set(hv, eiter);
4173 }
4174
4175 #endif
4176
4177 /*
4178 * ex: set ts=8 sts=4 sw=4 et:
4179 */
4180