source: for-distributions/trunk/bin/windows/perl/lib/CORE/hv.h@ 14489

Last change on this file since 14489 was 14489, checked in by oranfry, 17 years ago

upgrading to perl 5.8

File size: 13.3 KB
Line 
1/* hv.h
2 *
3 * Copyright (C) 1991, 1992, 1993, 1996, 1997, 1998, 1999,
4 * 2000, 2001, 2002, 2005, 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/* typedefs to eliminate some typing */
12typedef struct he HE;
13typedef struct hek HEK;
14
15/* entry in hash value chain */
16struct he {
17 HE *hent_next; /* next entry in chain */
18 HEK *hent_hek; /* hash key */
19 SV *hent_val; /* scalar value that was hashed */
20};
21
22/* hash key -- defined separately for use as shared pointer */
23struct hek {
24 U32 hek_hash; /* hash of key */
25 I32 hek_len; /* length of hash key */
26 char hek_key[1]; /* variable-length hash key */
27 /* the hash-key is \0-terminated */
28 /* after the \0 there is a byte for flags, such as whether the key
29 is UTF-8 */
30};
31
32/* hash structure: */
33/* This structure must match the beginning of struct xpvmg in sv.h. */
34struct xpvhv {
35 char * xhv_array; /* pointer to malloced string */
36 STRLEN xhv_fill; /* how full xhv_array currently is */
37 STRLEN xhv_max; /* subscript of last element of xhv_array */
38 IV xhv_keys; /* how many elements in the array */
39 NV xnv_nv; /* numeric value, if any */
40#define xhv_placeholders xnv_nv
41 MAGIC* xmg_magic; /* magic for scalar array */
42 HV* xmg_stash; /* class package */
43
44 I32 xhv_riter; /* current root of iterator */
45 HE *xhv_eiter; /* current entry of iterator */
46 PMOP *xhv_pmroot; /* list of pm's for this package */
47 char *xhv_name; /* name, if a symbol table */
48};
49
50/* hash a key */
51/* FYI: This is the "One-at-a-Time" algorithm by Bob Jenkins
52 * from requirements by Colin Plumb.
53 * (http://burtleburtle.net/bob/hash/doobs.html) */
54/* The use of a temporary pointer and the casting games
55 * is needed to serve the dual purposes of
56 * (a) the hashed data being interpreted as "unsigned char" (new since 5.8,
57 * a "char" can be either signed or unsigned, depending on the compiler)
58 * (b) catering for old code that uses a "char"
59 *
60 * The "hash seed" feature was added in Perl 5.8.1 to perturb the results
61 * to avoid "algorithmic complexity attacks".
62 *
63 * If USE_HASH_SEED is defined, hash randomisation is done by default
64 * If USE_HASH_SEED_EXPLICIT is defined, hash randomisation is done
65 * only if the environment variable PERL_HASH_SEED is set.
66 * For maximal control, one can define PERL_HASH_SEED.
67 * (see also perl.c:perl_parse()).
68 */
69#ifndef PERL_HASH_SEED
70# if defined(USE_HASH_SEED) || defined(USE_HASH_SEED_EXPLICIT)
71# define PERL_HASH_SEED PL_hash_seed
72# else
73# define PERL_HASH_SEED 0
74# endif
75#endif
76#define PERL_HASH(hash,str,len) \
77 STMT_START { \
78 register const char *s_PeRlHaSh_tmp = str; \
79 register const unsigned char *s_PeRlHaSh = (const unsigned char *)s_PeRlHaSh_tmp; \
80 register I32 i_PeRlHaSh = len; \
81 register U32 hash_PeRlHaSh = PERL_HASH_SEED; \
82 while (i_PeRlHaSh--) { \
83 hash_PeRlHaSh += *s_PeRlHaSh++; \
84 hash_PeRlHaSh += (hash_PeRlHaSh << 10); \
85 hash_PeRlHaSh ^= (hash_PeRlHaSh >> 6); \
86 } \
87 hash_PeRlHaSh += (hash_PeRlHaSh << 3); \
88 hash_PeRlHaSh ^= (hash_PeRlHaSh >> 11); \
89 (hash) = (hash_PeRlHaSh + (hash_PeRlHaSh << 15)); \
90 } STMT_END
91
92/* Only hv.c and mod_perl should be doing this. */
93#ifdef PERL_HASH_INTERNAL_ACCESS
94#define PERL_HASH_INTERNAL(hash,str,len) \
95 STMT_START { \
96 register const char *s_PeRlHaSh_tmp = str; \
97 register const unsigned char *s_PeRlHaSh = (const unsigned char *)s_PeRlHaSh_tmp; \
98 register I32 i_PeRlHaSh = len; \
99 register U32 hash_PeRlHaSh = PL_rehash_seed; \
100 while (i_PeRlHaSh--) { \
101 hash_PeRlHaSh += *s_PeRlHaSh++; \
102 hash_PeRlHaSh += (hash_PeRlHaSh << 10); \
103 hash_PeRlHaSh ^= (hash_PeRlHaSh >> 6); \
104 } \
105 hash_PeRlHaSh += (hash_PeRlHaSh << 3); \
106 hash_PeRlHaSh ^= (hash_PeRlHaSh >> 11); \
107 (hash) = (hash_PeRlHaSh + (hash_PeRlHaSh << 15)); \
108 } STMT_END
109#endif
110
111/*
112=head1 Hash Manipulation Functions
113
114=for apidoc AmU||HEf_SVKEY
115This flag, used in the length slot of hash entries and magic structures,
116specifies the structure contains an C<SV*> pointer where a C<char*> pointer
117is to be expected. (For information only--not to be used).
118
119=head1 Handy Values
120
121=for apidoc AmU||Nullhv
122Null HV pointer.
123
124=head1 Hash Manipulation Functions
125
126=for apidoc Am|char*|HvNAME|HV* stash
127Returns the package name of a stash, or NULL if C<stash> isn't a stash.
128See C<SvSTASH>, C<CvSTASH>.
129
130=for apidoc Am|void*|HeKEY|HE* he
131Returns the actual pointer stored in the key slot of the hash entry. The
132pointer may be either C<char*> or C<SV*>, depending on the value of
133C<HeKLEN()>. Can be assigned to. The C<HePV()> or C<HeSVKEY()> macros are
134usually preferable for finding the value of a key.
135
136=for apidoc Am|STRLEN|HeKLEN|HE* he
137If this is negative, and amounts to C<HEf_SVKEY>, it indicates the entry
138holds an C<SV*> key. Otherwise, holds the actual length of the key. Can
139be assigned to. The C<HePV()> macro is usually preferable for finding key
140lengths.
141
142=for apidoc Am|SV*|HeVAL|HE* he
143Returns the value slot (type C<SV*>) stored in the hash entry.
144
145=for apidoc Am|U32|HeHASH|HE* he
146Returns the computed hash stored in the hash entry.
147
148=for apidoc Am|char*|HePV|HE* he|STRLEN len
149Returns the key slot of the hash entry as a C<char*> value, doing any
150necessary dereferencing of possibly C<SV*> keys. The length of the string
151is placed in C<len> (this is a macro, so do I<not> use C<&len>). If you do
152not care about what the length of the key is, you may use the global
153variable C<PL_na>, though this is rather less efficient than using a local
154variable. Remember though, that hash keys in perl are free to contain
155embedded nulls, so using C<strlen()> or similar is not a good way to find
156the length of hash keys. This is very similar to the C<SvPV()> macro
157described elsewhere in this document.
158
159=for apidoc Am|SV*|HeSVKEY|HE* he
160Returns the key as an C<SV*>, or C<Nullsv> if the hash entry does not
161contain an C<SV*> key.
162
163=for apidoc Am|SV*|HeSVKEY_force|HE* he
164Returns the key as an C<SV*>. Will create and return a temporary mortal
165C<SV*> if the hash entry contains only a C<char*> key.
166
167=for apidoc Am|SV*|HeSVKEY_set|HE* he|SV* sv
168Sets the key to a given C<SV*>, taking care to set the appropriate flags to
169indicate the presence of an C<SV*> key, and returns the same
170C<SV*>.
171
172=cut
173*/
174
175/* these hash entry flags ride on hent_klen (for use only in magic/tied HVs) */
176#define HEf_SVKEY -2 /* hent_key is an SV* */
177
178
179#define Nullhv Null(HV*)
180#define HvARRAY(hv) (*(HE***)&((XPVHV*) SvANY(hv))->xhv_array)
181#define HvFILL(hv) ((XPVHV*) SvANY(hv))->xhv_fill
182#define HvMAX(hv) ((XPVHV*) SvANY(hv))->xhv_max
183#define HvRITER(hv) ((XPVHV*) SvANY(hv))->xhv_riter
184#define HvRITER_get(hv) (0 + ((XPVHV*) SvANY(hv))->xhv_riter)
185#define HvRITER_set(hv,r) (HvRITER(hv) = (r))
186#define HvEITER(hv) ((XPVHV*) SvANY(hv))->xhv_eiter
187#define HvEITER_get(hv) (0 + ((XPVHV*) SvANY(hv))->xhv_eiter)
188#define HvEITER_set(hv,e) (HvEITER(hv) = (e))
189#define HvPMROOT(hv) ((XPVHV*) SvANY(hv))->xhv_pmroot
190#define HvNAME(hv) ((XPVHV*) SvANY(hv))->xhv_name
191/* FIXME - all of these should use a UTF8 aware API, which should also involve
192 getting the length. */
193#define HvNAME_get(hv) (0 + ((XPVHV*) SvANY(hv))->xhv_name)
194#define hv_name_set(hv,name,length,flags) \
195 (HvNAME((hv)) = (name) ? savepvn(name, length) : 0)
196
197/* the number of keys (including any placeholers) */
198#define XHvTOTALKEYS(xhv) ((xhv)->xhv_keys)
199
200/* The number of placeholders in the enumerated-keys hash */
201#define XHvPLACEHOLDERS(xhv) ((xhv)->xhv_placeholders)
202
203/* the number of keys that exist() (i.e. excluding placeholders) */
204#define XHvUSEDKEYS(xhv) (XHvTOTALKEYS(xhv) - (IV)XHvPLACEHOLDERS(xhv))
205
206/*
207 * HvKEYS gets the number of keys that actually exist(), and is provided
208 * for backwards compatibility with old XS code. The core uses HvUSEDKEYS
209 * (keys, excluding placeholdes) and HvTOTALKEYS (including placeholders)
210 */
211#define HvKEYS(hv) XHvUSEDKEYS((XPVHV*) SvANY(hv))
212#define HvUSEDKEYS(hv) XHvUSEDKEYS((XPVHV*) SvANY(hv))
213#define HvTOTALKEYS(hv) XHvTOTALKEYS((XPVHV*) SvANY(hv))
214#define HvPLACEHOLDERS(hv) (XHvPLACEHOLDERS((XPVHV*) SvANY(hv)))
215#define HvPLACEHOLDERS_get(hv) (0 + XHvPLACEHOLDERS((XPVHV*) SvANY(hv)))
216#define HvPLACEHOLDERS_set(hv, p) \
217 (XHvPLACEHOLDERS((XPVHV*) SvANY(hv)) = (p))
218
219#define HvSHAREKEYS(hv) (SvFLAGS(hv) & SVphv_SHAREKEYS)
220#define HvSHAREKEYS_on(hv) (SvFLAGS(hv) |= SVphv_SHAREKEYS)
221#define HvSHAREKEYS_off(hv) (SvFLAGS(hv) &= ~SVphv_SHAREKEYS)
222
223/* This is an optimisation flag. It won't be set if all hash keys have a 0
224 * flag. Currently the only flags relate to utf8.
225 * Hence it won't be set if all keys are 8 bit only. It will be set if any key
226 * is utf8 (including 8 bit keys that were entered as utf8, and need upgrading
227 * when retrieved during iteration. It may still be set when there are no longer
228 * any utf8 keys.
229 * See HVhek_ENABLEHVKFLAGS for the trigger.
230 */
231#define HvHASKFLAGS(hv) (SvFLAGS(hv) & SVphv_HASKFLAGS)
232#define HvHASKFLAGS_on(hv) (SvFLAGS(hv) |= SVphv_HASKFLAGS)
233#define HvHASKFLAGS_off(hv) (SvFLAGS(hv) &= ~SVphv_HASKFLAGS)
234
235#define HvLAZYDEL(hv) (SvFLAGS(hv) & SVphv_LAZYDEL)
236#define HvLAZYDEL_on(hv) (SvFLAGS(hv) |= SVphv_LAZYDEL)
237#define HvLAZYDEL_off(hv) (SvFLAGS(hv) &= ~SVphv_LAZYDEL)
238
239#define HvREHASH(hv) (SvFLAGS(hv) & SVphv_REHASH)
240#define HvREHASH_on(hv) (SvFLAGS(hv) |= SVphv_REHASH)
241#define HvREHASH_off(hv) (SvFLAGS(hv) &= ~SVphv_REHASH)
242
243/* Maybe amagical: */
244/* #define HV_AMAGICmb(hv) (SvFLAGS(hv) & (SVpgv_badAM | SVpgv_AM)) */
245
246#define HV_AMAGIC(hv) (SvFLAGS(hv) & SVpgv_AM)
247#define HV_AMAGIC_on(hv) (SvFLAGS(hv) |= SVpgv_AM)
248#define HV_AMAGIC_off(hv) (SvFLAGS(hv) &= ~SVpgv_AM)
249
250/*
251#define HV_AMAGICbad(hv) (SvFLAGS(hv) & SVpgv_badAM)
252#define HV_badAMAGIC_on(hv) (SvFLAGS(hv) |= SVpgv_badAM)
253#define HV_badAMAGIC_off(hv) (SvFLAGS(hv) &= ~SVpgv_badAM)
254*/
255
256#define Nullhe Null(HE*)
257#define HeNEXT(he) (he)->hent_next
258#define HeKEY_hek(he) (he)->hent_hek
259#define HeKEY(he) HEK_KEY(HeKEY_hek(he))
260#define HeKEY_sv(he) (*(SV**)HeKEY(he))
261#define HeKLEN(he) HEK_LEN(HeKEY_hek(he))
262#define HeKUTF8(he) HEK_UTF8(HeKEY_hek(he))
263#define HeKWASUTF8(he) HEK_WASUTF8(HeKEY_hek(he))
264#define HeKREHASH(he) HEK_REHASH(HeKEY_hek(he))
265#define HeKLEN_UTF8(he) (HeKUTF8(he) ? -HeKLEN(he) : HeKLEN(he))
266#define HeKFLAGS(he) HEK_FLAGS(HeKEY_hek(he))
267#define HeVAL(he) (he)->hent_val
268#define HeHASH(he) HEK_HASH(HeKEY_hek(he))
269#define HePV(he,lp) ((HeKLEN(he) == HEf_SVKEY) ? \
270 SvPV(HeKEY_sv(he),lp) : \
271 (((lp = HeKLEN(he)) >= 0) ? \
272 HeKEY(he) : Nullch))
273
274#define HeSVKEY(he) ((HeKEY(he) && \
275 HeKLEN(he) == HEf_SVKEY) ? \
276 HeKEY_sv(he) : Nullsv)
277
278#define HeSVKEY_force(he) (HeKEY(he) ? \
279 ((HeKLEN(he) == HEf_SVKEY) ? \
280 HeKEY_sv(he) : \
281 sv_2mortal(newSVpvn(HeKEY(he), \
282 HeKLEN(he)))) : \
283 &PL_sv_undef)
284#define HeSVKEY_set(he,sv) ((HeKLEN(he) = HEf_SVKEY), (HeKEY_sv(he) = sv))
285
286#define Nullhek Null(HEK*)
287#define HEK_BASESIZE STRUCT_OFFSET(HEK, hek_key[0])
288#define HEK_HASH(hek) (hek)->hek_hash
289#define HEK_LEN(hek) (hek)->hek_len
290#define HEK_KEY(hek) (hek)->hek_key
291#define HEK_FLAGS(hek) (*((unsigned char *)(HEK_KEY(hek))+HEK_LEN(hek)+1))
292
293#define HVhek_UTF8 0x01 /* Key is utf8 encoded. */
294#define HVhek_WASUTF8 0x02 /* Key is bytes here, but was supplied as utf8. */
295#define HVhek_REHASH 0x04 /* This key is in an hv using a custom HASH . */
296#define HVhek_FREEKEY 0x100 /* Internal flag to say key is malloc()ed. */
297#define HVhek_PLACEHOLD 0x200 /* Internal flag to create placeholder.
298 * (may change, but Storable is a core module) */
299#define HVhek_MASK 0xFF
300
301/* Which flags enable HvHASKFLAGS? Somewhat a hack on a hack, as
302 HVhek_REHASH is only needed because the rehash flag has to be duplicated
303 into all keys as hv_iternext has no access to the hash flags. At this
304 point Storable's tests get upset, because sometimes hashes are "keyed"
305 and sometimes not, depending on the order of data insertion, and whether
306 it triggered rehashing. So currently HVhek_REHAS is exempt.
307*/
308
309#define HVhek_ENABLEHVKFLAGS (HVhek_MASK - HVhek_REHASH)
310
311#define HEK_UTF8(hek) (HEK_FLAGS(hek) & HVhek_UTF8)
312#define HEK_UTF8_on(hek) (HEK_FLAGS(hek) |= HVhek_UTF8)
313#define HEK_UTF8_off(hek) (HEK_FLAGS(hek) &= ~HVhek_UTF8)
314#define HEK_WASUTF8(hek) (HEK_FLAGS(hek) & HVhek_WASUTF8)
315#define HEK_WASUTF8_on(hek) (HEK_FLAGS(hek) |= HVhek_WASUTF8)
316#define HEK_WASUTF8_off(hek) (HEK_FLAGS(hek) &= ~HVhek_WASUTF8)
317#define HEK_REHASH(hek) (HEK_FLAGS(hek) & HVhek_REHASH)
318#define HEK_REHASH_on(hek) (HEK_FLAGS(hek) |= HVhek_REHASH)
319
320/* calculate HV array allocation */
321#ifndef PERL_USE_LARGE_HV_ALLOC
322/* Default to allocating the correct size - default to assuming that malloc()
323 is not broken and is efficient at allocating blocks sized at powers-of-two.
324*/
325# define PERL_HV_ARRAY_ALLOC_BYTES(size) ((size) * sizeof(HE*))
326#else
327# define MALLOC_OVERHEAD 16
328# define PERL_HV_ARRAY_ALLOC_BYTES(size) \
329 (((size) < 64) \
330 ? (size) * sizeof(HE*) \
331 : (size) * sizeof(HE*) * 2 - MALLOC_OVERHEAD)
332#endif
333
334/* Flags for hv_iternext_flags. */
335#define HV_ITERNEXT_WANTPLACEHOLDERS 0x01 /* Don't skip placeholders. */
336
337/* available as a function in hv.c */
338#define Perl_sharepvn(sv, len, hash) HEK_KEY(share_hek(sv, len, hash))
339#define sharepvn(sv, len, hash) Perl_sharepvn(sv, len, hash)
340
341/*
342 * Local variables:
343 * c-indentation-style: bsd
344 * c-basic-offset: 4
345 * indent-tabs-mode: t
346 * End:
347 *
348 * ex: set ts=8 sts=4 sw=4 noet:
349 */
Note: See TracBrowser for help on using the repository browser.