xref: /openbsd-src/gnu/usr.bin/perl/hv.h (revision f2da64fbbbf1b03f09f390ab01267c93dfd77c4c)
1 /*    hv.h
2  *
3  *    Copyright (C) 1991, 1992, 1993, 1996, 1997, 1998, 1999,
4  *    2000, 2001, 2002, 2003, 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 /* These control hash traversal randomization and the environment variable PERL_PERTURB_KEYS.
12  * Currently disabling this functionality will break a few tests, but should otherwise work fine.
13  * See perlrun for more details. */
14 
15 #if defined(PERL_PERTURB_KEYS_DISABLED)
16 #   define PL_HASH_RAND_BITS_ENABLED        0
17 #   define PERL_HASH_ITER_BUCKET(iter)      ((iter)->xhv_riter)
18 #else
19 #   define PERL_HASH_RANDOMIZE_KEYS         1
20 #   if defined(PERL_PERTURB_KEYS_RANDOM)
21 #       define PL_HASH_RAND_BITS_ENABLED    1
22 #   elif defined(PERL_PERTURB_KEYS_DETERMINISTIC)
23 #       define PL_HASH_RAND_BITS_ENABLED    2
24 #   else
25 #       define USE_PERL_PERTURB_KEYS        1
26 #       define PL_HASH_RAND_BITS_ENABLED    PL_hash_rand_bits_enabled
27 #   endif
28 #   define PERL_HASH_ITER_BUCKET(iter)      (((iter)->xhv_riter) ^ ((iter)->xhv_rand))
29 #endif
30 
31 /* entry in hash value chain */
32 struct he {
33     /* Keep hent_next first in this structure, because sv_free_arenas take
34        advantage of this to share code between the he arenas and the SV
35        body arenas  */
36     HE		*hent_next;	/* next entry in chain */
37     HEK		*hent_hek;	/* hash key */
38     union {
39 	SV	*hent_val;	/* scalar value that was hashed */
40 	Size_t	hent_refcount;	/* references for this shared hash key */
41     } he_valu;
42 };
43 
44 /* hash key -- defined separately for use as shared pointer */
45 struct hek {
46     U32		hek_hash;	/* hash of key */
47     I32		hek_len;	/* length of hash key */
48     char	hek_key[1];	/* variable-length hash key */
49     /* the hash-key is \0-terminated */
50     /* after the \0 there is a byte for flags, such as whether the key
51        is UTF-8 */
52 };
53 
54 struct shared_he {
55     struct he shared_he_he;
56     struct hek shared_he_hek;
57 };
58 
59 /* Subject to change.
60    Don't access this directly.
61    Use the funcs in mro.c
62 */
63 
64 struct mro_alg {
65     AV *(*resolve)(pTHX_ HV* stash, U32 level);
66     const char *name;
67     U16 length;
68     U16	kflags;	/* For the hash API - set HVhek_UTF8 if name is UTF-8 */
69     U32 hash; /* or 0 */
70 };
71 
72 struct mro_meta {
73     /* a hash holding the different MROs private data.  */
74     HV      *mro_linear_all;
75     /* a pointer directly to the current MROs private data.  If mro_linear_all
76        is NULL, this owns the SV reference, else it is just a pointer to a
77        value stored in and owned by mro_linear_all.  */
78     SV      *mro_linear_current;
79     HV      *mro_nextmethod; /* next::method caching */
80     U32     cache_gen;       /* Bumping this invalidates our method cache */
81     U32     pkg_gen;         /* Bumps when local methods/@ISA change */
82     const struct mro_alg *mro_which; /* which mro alg is in use? */
83     HV      *isa;            /* Everything this class @ISA */
84     HV      *super;          /* SUPER method cache */
85     U32     destroy_gen;     /* Generation number of DESTROY cache */
86 };
87 
88 #define MRO_GET_PRIVATE_DATA(smeta, which)		   \
89     (((smeta)->mro_which && (which) == (smeta)->mro_which) \
90      ? (smeta)->mro_linear_current			   \
91      : Perl_mro_get_private_data(aTHX_ (smeta), (which)))
92 
93 /* Subject to change.
94    Don't access this directly.
95 */
96 
97 union _xhvnameu {
98     HEK *xhvnameu_name;		/* When xhv_name_count is 0 */
99     HEK **xhvnameu_names;	/* When xhv_name_count is non-0 */
100 };
101 
102 struct xpvhv_aux {
103     union _xhvnameu xhv_name_u;	/* name, if a symbol table */
104     AV		*xhv_backreferences; /* back references for weak references */
105     HE		*xhv_eiter;	/* current entry of iterator */
106     I32		xhv_riter;	/* current root of iterator */
107 
108 /* Concerning xhv_name_count: When non-zero, xhv_name_u contains a pointer
109  * to an array of HEK pointers, this being the length. The first element is
110  * the name of the stash, which may be NULL. If xhv_name_count is positive,
111  * then *xhv_name is one of the effective names. If xhv_name_count is nega-
112  * tive, then xhv_name_u.xhvnameu_names[1] is the first effective name.
113  */
114     I32		xhv_name_count;
115     struct mro_meta *xhv_mro_meta;
116 #ifdef PERL_HASH_RANDOMIZE_KEYS
117     U32         xhv_rand;       /* random value for hash traversal */
118     U32         xhv_last_rand;  /* last random value for hash traversal,
119                                    used to detect each() after insert for warnings */
120 #endif
121     U32         xhv_fill_lazy;
122     U32         xhv_aux_flags;      /* assorted extra flags */
123 };
124 
125 #define HvAUXf_SCAN_STASH   0x1   /* stash is being scanned by gv_check */
126 #define HvAUXf_NO_DEREF     0x2   /* @{}, %{} etc (and nomethod) not present */
127 
128 /* hash structure: */
129 /* This structure must match the beginning of struct xpvmg in sv.h. */
130 struct xpvhv {
131     HV*		xmg_stash;	/* class package */
132     union _xmgu	xmg_u;
133     STRLEN      xhv_keys;       /* total keys, including placeholders */
134     STRLEN      xhv_max;        /* subscript of last element of xhv_array */
135 };
136 
137 /*
138 =head1 Hash Manipulation Functions
139 
140 =for apidoc AmU||HEf_SVKEY
141 This flag, used in the length slot of hash entries and magic structures,
142 specifies the structure contains an C<SV*> pointer where a C<char*> pointer
143 is to be expected.  (For information only--not to be used).
144 
145 =head1 Handy Values
146 
147 =for apidoc AmU||Nullhv
148 Null HV pointer.
149 
150 (deprecated - use C<(HV *)NULL> instead)
151 
152 =head1 Hash Manipulation Functions
153 
154 =for apidoc Am|char*|HvNAME|HV* stash
155 Returns the package name of a stash, or NULL if C<stash> isn't a stash.
156 See C<SvSTASH>, C<CvSTASH>.
157 
158 =for apidoc Am|STRLEN|HvNAMELEN|HV *stash
159 Returns the length of the stash's name.
160 
161 =for apidoc Am|unsigned char|HvNAMEUTF8|HV *stash
162 Returns true if the name is in UTF8 encoding.
163 
164 =for apidoc Am|char*|HvENAME|HV* stash
165 Returns the effective name of a stash, or NULL if there is none.  The
166 effective name represents a location in the symbol table where this stash
167 resides.  It is updated automatically when packages are aliased or deleted.
168 A stash that is no longer in the symbol table has no effective name.  This
169 name is preferable to C<HvNAME> for use in MRO linearisations and isa
170 caches.
171 
172 =for apidoc Am|STRLEN|HvENAMELEN|HV *stash
173 Returns the length of the stash's effective name.
174 
175 =for apidoc Am|unsigned char|HvENAMEUTF8|HV *stash
176 Returns true if the effective name is in UTF8 encoding.
177 
178 =for apidoc Am|void*|HeKEY|HE* he
179 Returns the actual pointer stored in the key slot of the hash entry.  The
180 pointer may be either C<char*> or C<SV*>, depending on the value of
181 C<HeKLEN()>.  Can be assigned to.  The C<HePV()> or C<HeSVKEY()> macros are
182 usually preferable for finding the value of a key.
183 
184 =for apidoc Am|STRLEN|HeKLEN|HE* he
185 If this is negative, and amounts to C<HEf_SVKEY>, it indicates the entry
186 holds an C<SV*> key.  Otherwise, holds the actual length of the key.  Can
187 be assigned to.  The C<HePV()> macro is usually preferable for finding key
188 lengths.
189 
190 =for apidoc Am|SV*|HeVAL|HE* he
191 Returns the value slot (type C<SV*>)
192 stored in the hash entry.  Can be assigned
193 to.
194 
195   SV *foo= HeVAL(hv);
196   HeVAL(hv)= sv;
197 
198 
199 =for apidoc Am|U32|HeHASH|HE* he
200 Returns the computed hash stored in the hash entry.
201 
202 =for apidoc Am|char*|HePV|HE* he|STRLEN len
203 Returns the key slot of the hash entry as a C<char*> value, doing any
204 necessary dereferencing of possibly C<SV*> keys.  The length of the string
205 is placed in C<len> (this is a macro, so do I<not> use C<&len>).  If you do
206 not care about what the length of the key is, you may use the global
207 variable C<PL_na>, though this is rather less efficient than using a local
208 variable.  Remember though, that hash keys in perl are free to contain
209 embedded nulls, so using C<strlen()> or similar is not a good way to find
210 the length of hash keys.  This is very similar to the C<SvPV()> macro
211 described elsewhere in this document.  See also C<HeUTF8>.
212 
213 If you are using C<HePV> to get values to pass to C<newSVpvn()> to create a
214 new SV, you should consider using C<newSVhek(HeKEY_hek(he))> as it is more
215 efficient.
216 
217 =for apidoc Am|U32|HeUTF8|HE* he
218 Returns whether the C<char *> value returned by C<HePV> is encoded in UTF-8,
219 doing any necessary dereferencing of possibly C<SV*> keys.  The value returned
220 will be 0 or non-0, not necessarily 1 (or even a value with any low bits set),
221 so B<do not> blindly assign this to a C<bool> variable, as C<bool> may be a
222 typedef for C<char>.
223 
224 =for apidoc Am|SV*|HeSVKEY|HE* he
225 Returns the key as an C<SV*>, or C<NULL> if the hash entry does not
226 contain an C<SV*> key.
227 
228 =for apidoc Am|SV*|HeSVKEY_force|HE* he
229 Returns the key as an C<SV*>.  Will create and return a temporary mortal
230 C<SV*> if the hash entry contains only a C<char*> key.
231 
232 =for apidoc Am|SV*|HeSVKEY_set|HE* he|SV* sv
233 Sets the key to a given C<SV*>, taking care to set the appropriate flags to
234 indicate the presence of an C<SV*> key, and returns the same
235 C<SV*>.
236 
237 =cut
238 */
239 
240 #define PERL_HASH_DEFAULT_HvMAX 7
241 
242 /* During hsplit(), if HvMAX(hv)+1 (the new bucket count) is >= this value,
243  * we preallocate the HvAUX() struct.
244  * The assumption being that we are using so much space anyway we might
245  * as well allocate the extra bytes and speed up later keys()
246  * or each() operations. We don't do this to small hashes as we assume
247  * that a) it will be easy/fast to resize them to add the iterator, and b) that
248  * many of them will be objects which won't be traversed. Larger hashes however
249  * will take longer to extend, and the size of the aux struct is swamped by the
250  * overall length of the bucket array.
251  * */
252 #define PERL_HV_ALLOC_AUX_SIZE (1 << 9)
253 
254 /* these hash entry flags ride on hent_klen (for use only in magic/tied HVs) */
255 #define HEf_SVKEY	-2	/* hent_key is an SV* */
256 
257 #ifndef PERL_CORE
258 #  define Nullhv Null(HV*)
259 #endif
260 #define HvARRAY(hv)	((hv)->sv_u.svu_hash)
261 #define HvFILL(hv)	Perl_hv_fill(aTHX_ MUTABLE_HV(hv))
262 #define HvMAX(hv)	((XPVHV*)  SvANY(hv))->xhv_max
263 /* This quite intentionally does no flag checking first. That's your
264    responsibility.  */
265 #define HvAUX(hv)	((struct xpvhv_aux*)&(HvARRAY(hv)[HvMAX(hv)+1]))
266 #define HvRITER(hv)	(*Perl_hv_riter_p(aTHX_ MUTABLE_HV(hv)))
267 #define HvEITER(hv)	(*Perl_hv_eiter_p(aTHX_ MUTABLE_HV(hv)))
268 #define HvRITER_set(hv,r)	Perl_hv_riter_set(aTHX_ MUTABLE_HV(hv), r)
269 #define HvEITER_set(hv,e)	Perl_hv_eiter_set(aTHX_ MUTABLE_HV(hv), e)
270 #define HvRITER_get(hv)	(SvOOK(hv) ? HvAUX(hv)->xhv_riter : -1)
271 #define HvEITER_get(hv)	(SvOOK(hv) ? HvAUX(hv)->xhv_eiter : NULL)
272 #define HvRAND_get(hv)	(SvOOK(hv) ? HvAUX(hv)->xhv_rand : 0)
273 #define HvLASTRAND_get(hv)	(SvOOK(hv) ? HvAUX(hv)->xhv_last_rand : 0)
274 
275 #define HvNAME(hv)	HvNAME_get(hv)
276 #define HvNAMELEN(hv)   HvNAMELEN_get(hv)
277 #define HvENAME(hv)	HvENAME_get(hv)
278 #define HvENAMELEN(hv)  HvENAMELEN_get(hv)
279 
280 /* Checking that hv is a valid package stash is the
281    caller's responsibility */
282 #define HvMROMETA(hv) (HvAUX(hv)->xhv_mro_meta \
283                        ? HvAUX(hv)->xhv_mro_meta \
284                        : Perl_mro_meta_init(aTHX_ hv))
285 
286 #define HvNAME_HEK_NN(hv)			  \
287  (						  \
288   HvAUX(hv)->xhv_name_count			  \
289   ? *HvAUX(hv)->xhv_name_u.xhvnameu_names	  \
290   : HvAUX(hv)->xhv_name_u.xhvnameu_name		  \
291  )
292 /* This macro may go away without notice.  */
293 #define HvNAME_HEK(hv) \
294 	(SvOOK(hv) && HvAUX(hv)->xhv_name_u.xhvnameu_name ? HvNAME_HEK_NN(hv) : NULL)
295 #define HvNAME_get(hv) \
296 	((SvOOK(hv) && HvAUX(hv)->xhv_name_u.xhvnameu_name && HvNAME_HEK_NN(hv)) \
297 			 ? HEK_KEY(HvNAME_HEK_NN(hv)) : NULL)
298 #define HvNAMELEN_get(hv) \
299 	((SvOOK(hv) && HvAUX(hv)->xhv_name_u.xhvnameu_name && HvNAME_HEK_NN(hv)) \
300 				 ? HEK_LEN(HvNAME_HEK_NN(hv)) : 0)
301 #define HvNAMEUTF8(hv) \
302 	((SvOOK(hv) && HvAUX(hv)->xhv_name_u.xhvnameu_name && HvNAME_HEK_NN(hv)) \
303 				 ? HEK_UTF8(HvNAME_HEK_NN(hv)) : 0)
304 #define HvENAME_HEK_NN(hv)                                             \
305  (                                                                      \
306   HvAUX(hv)->xhv_name_count > 0   ? HvAUX(hv)->xhv_name_u.xhvnameu_names[0] : \
307   HvAUX(hv)->xhv_name_count < -1  ? HvAUX(hv)->xhv_name_u.xhvnameu_names[1] : \
308   HvAUX(hv)->xhv_name_count == -1 ? NULL                              : \
309                                     HvAUX(hv)->xhv_name_u.xhvnameu_name \
310  )
311 #define HvENAME_HEK(hv) \
312 	(SvOOK(hv) && HvAUX(hv)->xhv_name_u.xhvnameu_name ? HvENAME_HEK_NN(hv) : NULL)
313 #define HvENAME_get(hv) \
314    ((SvOOK(hv) && HvAUX(hv)->xhv_name_u.xhvnameu_name && HvAUX(hv)->xhv_name_count != -1) \
315 			 ? HEK_KEY(HvENAME_HEK_NN(hv)) : NULL)
316 #define HvENAMELEN_get(hv) \
317    ((SvOOK(hv) && HvAUX(hv)->xhv_name_u.xhvnameu_name && HvAUX(hv)->xhv_name_count != -1) \
318 				 ? HEK_LEN(HvENAME_HEK_NN(hv)) : 0)
319 #define HvENAMEUTF8(hv) \
320    ((SvOOK(hv) && HvAUX(hv)->xhv_name_u.xhvnameu_name && HvAUX(hv)->xhv_name_count != -1) \
321 				 ? HEK_UTF8(HvENAME_HEK_NN(hv)) : 0)
322 
323 /* the number of keys (including any placeholders) */
324 #define XHvTOTALKEYS(xhv)	((xhv)->xhv_keys)
325 
326 /*
327  * HvKEYS gets the number of keys that actually exist(), and is provided
328  * for backwards compatibility with old XS code. The core uses HvUSEDKEYS
329  * (keys, excluding placeholders) and HvTOTALKEYS (including placeholders)
330  */
331 #define HvKEYS(hv)		HvUSEDKEYS(hv)
332 #define HvUSEDKEYS(hv)		(HvTOTALKEYS(hv) - HvPLACEHOLDERS_get(hv))
333 #define HvTOTALKEYS(hv)		XHvTOTALKEYS((XPVHV*)  SvANY(hv))
334 #define HvPLACEHOLDERS(hv)	(*Perl_hv_placeholders_p(aTHX_ MUTABLE_HV(hv)))
335 #define HvPLACEHOLDERS_get(hv)	(SvMAGIC(hv) ? Perl_hv_placeholders_get(aTHX_ (const HV *)hv) : 0)
336 #define HvPLACEHOLDERS_set(hv,p)	Perl_hv_placeholders_set(aTHX_ MUTABLE_HV(hv), p)
337 
338 #define HvSHAREKEYS(hv)		(SvFLAGS(hv) & SVphv_SHAREKEYS)
339 #define HvSHAREKEYS_on(hv)	(SvFLAGS(hv) |= SVphv_SHAREKEYS)
340 #define HvSHAREKEYS_off(hv)	(SvFLAGS(hv) &= ~SVphv_SHAREKEYS)
341 
342 /* This is an optimisation flag. It won't be set if all hash keys have a 0
343  * flag. Currently the only flags relate to utf8.
344  * Hence it won't be set if all keys are 8 bit only. It will be set if any key
345  * is utf8 (including 8 bit keys that were entered as utf8, and need upgrading
346  * when retrieved during iteration. It may still be set when there are no longer
347  * any utf8 keys.
348  * See HVhek_ENABLEHVKFLAGS for the trigger.
349  */
350 #define HvHASKFLAGS(hv)		(SvFLAGS(hv) & SVphv_HASKFLAGS)
351 #define HvHASKFLAGS_on(hv)	(SvFLAGS(hv) |= SVphv_HASKFLAGS)
352 #define HvHASKFLAGS_off(hv)	(SvFLAGS(hv) &= ~SVphv_HASKFLAGS)
353 
354 #define HvLAZYDEL(hv)		(SvFLAGS(hv) & SVphv_LAZYDEL)
355 #define HvLAZYDEL_on(hv)	(SvFLAGS(hv) |= SVphv_LAZYDEL)
356 #define HvLAZYDEL_off(hv)	(SvFLAGS(hv) &= ~SVphv_LAZYDEL)
357 
358 #ifndef PERL_CORE
359 #  define Nullhe Null(HE*)
360 #endif
361 #define HeNEXT(he)		(he)->hent_next
362 #define HeKEY_hek(he)		(he)->hent_hek
363 #define HeKEY(he)		HEK_KEY(HeKEY_hek(he))
364 #define HeKEY_sv(he)		(*(SV**)HeKEY(he))
365 #define HeKLEN(he)		HEK_LEN(HeKEY_hek(he))
366 #define HeKUTF8(he)  HEK_UTF8(HeKEY_hek(he))
367 #define HeKWASUTF8(he)  HEK_WASUTF8(HeKEY_hek(he))
368 #define HeKLEN_UTF8(he)  (HeKUTF8(he) ? -HeKLEN(he) : HeKLEN(he))
369 #define HeKFLAGS(he)  HEK_FLAGS(HeKEY_hek(he))
370 #define HeVAL(he)		(he)->he_valu.hent_val
371 #define HeHASH(he)		HEK_HASH(HeKEY_hek(he))
372 #define HePV(he,lp)		((HeKLEN(he) == HEf_SVKEY) ?		\
373 				 SvPV(HeKEY_sv(he),lp) :		\
374 				 ((lp = HeKLEN(he)), HeKEY(he)))
375 #define HeUTF8(he)		((HeKLEN(he) == HEf_SVKEY) ?		\
376 				 SvUTF8(HeKEY_sv(he)) :			\
377 				 (U32)HeKUTF8(he))
378 
379 #define HeSVKEY(he)		((HeKEY(he) && 				\
380 				  HeKLEN(he) == HEf_SVKEY) ?		\
381 				 HeKEY_sv(he) : NULL)
382 
383 #define HeSVKEY_force(he)	(HeKEY(he) ?				\
384 				 ((HeKLEN(he) == HEf_SVKEY) ?		\
385 				  HeKEY_sv(he) :			\
386 				  newSVpvn_flags(HeKEY(he),		\
387                                                  HeKLEN(he),            \
388                                                  SVs_TEMP |             \
389                                       ( HeKUTF8(he) ? SVf_UTF8 : 0 ))) : \
390 				 &PL_sv_undef)
391 #define HeSVKEY_set(he,sv)	((HeKLEN(he) = HEf_SVKEY), (HeKEY_sv(he) = sv))
392 
393 #ifndef PERL_CORE
394 #  define Nullhek Null(HEK*)
395 #endif
396 #define HEK_BASESIZE		STRUCT_OFFSET(HEK, hek_key[0])
397 #define HEK_HASH(hek)		(hek)->hek_hash
398 #define HEK_LEN(hek)		(hek)->hek_len
399 #define HEK_KEY(hek)		(hek)->hek_key
400 #define HEK_FLAGS(hek)	(*((unsigned char *)(HEK_KEY(hek))+HEK_LEN(hek)+1))
401 
402 #define HVhek_UTF8	0x01 /* Key is utf8 encoded. */
403 #define HVhek_WASUTF8	0x02 /* Key is bytes here, but was supplied as utf8. */
404 #define HVhek_UNSHARED	0x08 /* This key isn't a shared hash key. */
405 #define HVhek_FREEKEY	0x100 /* Internal flag to say key is malloc()ed.  */
406 #define HVhek_PLACEHOLD	0x200 /* Internal flag to create placeholder.
407                                * (may change, but Storable is a core module) */
408 #define HVhek_KEYCANONICAL 0x400 /* Internal flag - key is in canonical form.
409 				    If the string is UTF-8, it cannot be
410 				    converted to bytes. */
411 #define HVhek_MASK	0xFF
412 
413 #define HVhek_ENABLEHVKFLAGS        (HVhek_MASK & ~(HVhek_UNSHARED))
414 
415 #define HEK_UTF8(hek)		(HEK_FLAGS(hek) & HVhek_UTF8)
416 #define HEK_UTF8_on(hek)	(HEK_FLAGS(hek) |= HVhek_UTF8)
417 #define HEK_UTF8_off(hek)	(HEK_FLAGS(hek) &= ~HVhek_UTF8)
418 #define HEK_WASUTF8(hek)	(HEK_FLAGS(hek) & HVhek_WASUTF8)
419 #define HEK_WASUTF8_on(hek)	(HEK_FLAGS(hek) |= HVhek_WASUTF8)
420 #define HEK_WASUTF8_off(hek)	(HEK_FLAGS(hek) &= ~HVhek_WASUTF8)
421 
422 /* calculate HV array allocation */
423 #ifndef PERL_USE_LARGE_HV_ALLOC
424 /* Default to allocating the correct size - default to assuming that malloc()
425    is not broken and is efficient at allocating blocks sized at powers-of-two.
426 */
427 #  define PERL_HV_ARRAY_ALLOC_BYTES(size) ((size) * sizeof(HE*))
428 #else
429 #  define MALLOC_OVERHEAD 16
430 #  define PERL_HV_ARRAY_ALLOC_BYTES(size) \
431 			(((size) < 64)					\
432 			 ? (size) * sizeof(HE*)				\
433 			 : (size) * sizeof(HE*) * 2 - MALLOC_OVERHEAD)
434 #endif
435 
436 /* Flags for hv_iternext_flags.  */
437 #define HV_ITERNEXT_WANTPLACEHOLDERS	0x01	/* Don't skip placeholders.  */
438 
439 #define hv_iternext(hv)	hv_iternext_flags(hv, 0)
440 #define hv_magic(hv, gv, how) sv_magic(MUTABLE_SV(hv), MUTABLE_SV(gv), how, NULL, 0)
441 #define hv_undef(hv) Perl_hv_undef_flags(aTHX_ hv, 0)
442 
443 #define Perl_sharepvn(pv, len, hash) HEK_KEY(share_hek(pv, len, hash))
444 #define sharepvn(pv, len, hash)	     Perl_sharepvn(pv, len, hash)
445 
446 #define share_hek_hek(hek)						\
447     (++(((struct shared_he *)(((char *)hek)				\
448 			      - STRUCT_OFFSET(struct shared_he,		\
449 					      shared_he_hek)))		\
450 	->shared_he_he.he_valu.hent_refcount),				\
451      hek)
452 
453 #define hv_store_ent(hv, keysv, val, hash)				\
454     ((HE *) hv_common((hv), (keysv), NULL, 0, 0, HV_FETCH_ISSTORE,	\
455 		      (val), (hash)))
456 
457 #define hv_exists_ent(hv, keysv, hash)					\
458     (hv_common((hv), (keysv), NULL, 0, 0, HV_FETCH_ISEXISTS, 0, (hash))	\
459      ? TRUE : FALSE)
460 #define hv_fetch_ent(hv, keysv, lval, hash)				\
461     ((HE *) hv_common((hv), (keysv), NULL, 0, 0,			\
462 		      ((lval) ? HV_FETCH_LVALUE : 0), NULL, (hash)))
463 #define hv_delete_ent(hv, key, flags, hash)				\
464     (MUTABLE_SV(hv_common((hv), (key), NULL, 0, 0, (flags) | HV_DELETE,	\
465 			  NULL, (hash))))
466 
467 #define hv_store_flags(hv, key, klen, val, hash, flags)			\
468     ((SV**) hv_common((hv), NULL, (key), (klen), (flags),		\
469 		      (HV_FETCH_ISSTORE|HV_FETCH_JUST_SV), (val),	\
470 		      (hash)))
471 
472 #define hv_store(hv, key, klen, val, hash)				\
473     ((SV**) hv_common_key_len((hv), (key), (klen),			\
474 			      (HV_FETCH_ISSTORE|HV_FETCH_JUST_SV),	\
475 			      (val), (hash)))
476 
477 #define hv_exists(hv, key, klen)					\
478     (hv_common_key_len((hv), (key), (klen), HV_FETCH_ISEXISTS, NULL, 0) \
479      ? TRUE : FALSE)
480 
481 #define hv_fetch(hv, key, klen, lval)					\
482     ((SV**) hv_common_key_len((hv), (key), (klen), (lval)		\
483 			      ? (HV_FETCH_JUST_SV | HV_FETCH_LVALUE)	\
484 			      : HV_FETCH_JUST_SV, NULL, 0))
485 
486 #define hv_delete(hv, key, klen, flags)					\
487     (MUTABLE_SV(hv_common_key_len((hv), (key), (klen),			\
488 				  (flags) | HV_DELETE, NULL, 0)))
489 
490 #ifdef PERL_CORE
491 # define hv_storehek(hv, hek, val) \
492     hv_common((hv), NULL, HEK_KEY(hek), HEK_LEN(hek), HEK_UTF8(hek),	\
493 	      HV_FETCH_ISSTORE|HV_FETCH_JUST_SV, (val), HEK_HASH(hek))
494 # define hv_fetchhek(hv, hek, lval) \
495     ((SV **)								\
496      hv_common((hv), NULL, HEK_KEY(hek), HEK_LEN(hek), HEK_UTF8(hek),	\
497 	       (lval)							\
498 		? (HV_FETCH_JUST_SV | HV_FETCH_LVALUE)			\
499 		: HV_FETCH_JUST_SV,					\
500 	       NULL, HEK_HASH(hek)))
501 # define hv_deletehek(hv, hek, flags) \
502     hv_common((hv), NULL, HEK_KEY(hek), HEK_LEN(hek), HEK_UTF8(hek), \
503 	      (flags)|HV_DELETE, NULL, HEK_HASH(hek))
504 #endif
505 
506 /* This refcounted he structure is used for storing the hints used for lexical
507    pragmas. Without threads, it's basically struct he + refcount.
508    With threads, life gets more complex as the structure needs to be shared
509    between threads (because it hangs from OPs, which are shared), hence the
510    alternate definition and mutex.  */
511 
512 struct refcounted_he;
513 
514 /* flags for the refcounted_he API */
515 #define REFCOUNTED_HE_KEY_UTF8		0x00000001
516 #ifdef PERL_CORE
517 # define REFCOUNTED_HE_EXISTS		0x00000002
518 #endif
519 
520 #ifdef PERL_CORE
521 
522 /* Gosh. This really isn't a good name any longer.  */
523 struct refcounted_he {
524     struct refcounted_he *refcounted_he_next;	/* next entry in chain */
525 #ifdef USE_ITHREADS
526     U32                   refcounted_he_hash;
527     U32                   refcounted_he_keylen;
528 #else
529     HEK                  *refcounted_he_hek;	/* hint key */
530 #endif
531     union {
532 	IV                refcounted_he_u_iv;
533 	UV                refcounted_he_u_uv;
534 	STRLEN            refcounted_he_u_len;
535 	void		 *refcounted_he_u_ptr;	/* Might be useful in future */
536     } refcounted_he_val;
537     U32	                  refcounted_he_refcnt;	/* reference count */
538     /* First byte is flags. Then NUL-terminated value. Then for ithreads,
539        non-NUL terminated key.  */
540     char                  refcounted_he_data[1];
541 };
542 
543 /*
544 =for apidoc m|SV *|refcounted_he_fetch_pvs|const struct refcounted_he *chain|const char *key|U32 flags
545 
546 Like L</refcounted_he_fetch_pvn>, but takes a literal string instead of
547 a string/length pair, and no precomputed hash.
548 
549 =cut
550 */
551 
552 #define refcounted_he_fetch_pvs(chain, key, flags) \
553     Perl_refcounted_he_fetch_pvn(aTHX_ chain, STR_WITH_LEN(key), 0, flags)
554 
555 /*
556 =for apidoc m|struct refcounted_he *|refcounted_he_new_pvs|struct refcounted_he *parent|const char *key|SV *value|U32 flags
557 
558 Like L</refcounted_he_new_pvn>, but takes a literal string instead of
559 a string/length pair, and no precomputed hash.
560 
561 =cut
562 */
563 
564 #define refcounted_he_new_pvs(parent, key, value, flags) \
565     Perl_refcounted_he_new_pvn(aTHX_ parent, STR_WITH_LEN(key), 0, value, flags)
566 
567 /* Flag bits are HVhek_UTF8, HVhek_WASUTF8, then */
568 #define HVrhek_undef	0x00 /* Value is undef. */
569 #define HVrhek_delete	0x10 /* Value is placeholder - signifies delete. */
570 #define HVrhek_IV	0x20 /* Value is IV. */
571 #define HVrhek_UV	0x30 /* Value is UV. */
572 #define HVrhek_PV	0x40 /* Value is a (byte) string. */
573 #define HVrhek_PV_UTF8	0x50 /* Value is a (utf8) string. */
574 /* Two spare. As these have to live in the optree, you can't store anything
575    interpreter specific, such as SVs. :-( */
576 #define HVrhek_typemask 0x70
577 
578 #ifdef USE_ITHREADS
579 /* A big expression to find the key offset */
580 #define REF_HE_KEY(chain)						\
581 	((((chain->refcounted_he_data[0] & 0x60) == 0x40)		\
582 	    ? chain->refcounted_he_val.refcounted_he_u_len + 1 : 0)	\
583 	 + 1 + chain->refcounted_he_data)
584 #endif
585 
586 #  ifdef USE_ITHREADS
587 #    define HINTS_REFCNT_LOCK		MUTEX_LOCK(&PL_hints_mutex)
588 #    define HINTS_REFCNT_UNLOCK		MUTEX_UNLOCK(&PL_hints_mutex)
589 #  else
590 #    define HINTS_REFCNT_LOCK		NOOP
591 #    define HINTS_REFCNT_UNLOCK		NOOP
592 #  endif
593 #endif
594 
595 #ifdef USE_ITHREADS
596 #  define HINTS_REFCNT_INIT		MUTEX_INIT(&PL_hints_mutex)
597 #  define HINTS_REFCNT_TERM		MUTEX_DESTROY(&PL_hints_mutex)
598 #else
599 #  define HINTS_REFCNT_INIT		NOOP
600 #  define HINTS_REFCNT_TERM		NOOP
601 #endif
602 
603 /* Hash actions
604  * Passed in PERL_MAGIC_uvar calls
605  */
606 #define HV_DISABLE_UVAR_XKEY	0x01
607 /* We need to ensure that these don't clash with G_DISCARD, which is 2, as it
608    is documented as being passed to hv_delete().  */
609 #define HV_FETCH_ISSTORE	0x04
610 #define HV_FETCH_ISEXISTS	0x08
611 #define HV_FETCH_LVALUE		0x10
612 #define HV_FETCH_JUST_SV	0x20
613 #define HV_DELETE		0x40
614 #define HV_FETCH_EMPTY_HE	0x80 /* Leave HeVAL null. */
615 
616 /* Must not conflict with HVhek_UTF8 */
617 #define HV_NAME_SETALL		0x02
618 
619 /*
620 =for apidoc newHV
621 
622 Creates a new HV.  The reference count is set to 1.
623 
624 =cut
625 */
626 
627 #define newHV()	MUTABLE_HV(newSV_type(SVt_PVHV))
628 
629 #include "hv_func.h"
630 
631 /*
632  * Local variables:
633  * c-indentation-style: bsd
634  * c-basic-offset: 4
635  * indent-tabs-mode: nil
636  * End:
637  *
638  * ex: set ts=8 sts=4 sw=4 et:
639  */
640