Commit | Line | Data |
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a0d0e21e | 1 | /* hv.h |
79072805 | 2 | * |
4bb101f2 | 3 | * Copyright (C) 1991, 1992, 1993, 1996, 1997, 1998, 1999, |
1d325971 | 4 | * 2000, 2001, 2002, 2005, by Larry Wall and others |
79072805 LW |
5 | * |
6 | * You may distribute under the terms of either the GNU General Public | |
7 | * License or the Artistic License, as specified in the README file. | |
8 | * | |
79072805 LW |
9 | */ |
10 | ||
5cbe4eec | 11 | /* typedefs to eliminate some typing */ |
79072805 | 12 | typedef struct he HE; |
ff68c719 | 13 | typedef struct hek HEK; |
79072805 | 14 | |
5cbe4eec | 15 | /* entry in hash value chain */ |
79072805 | 16 | struct he { |
5cbe4eec MLF |
17 | HE *hent_next; /* next entry in chain */ |
18 | HEK *hent_hek; /* hash key */ | |
19 | SV *hent_val; /* scalar value that was hashed */ | |
bbce6d69 | 20 | }; |
21 | ||
5cbe4eec | 22 | /* hash key -- defined separately for use as shared pointer */ |
ff68c719 | 23 | struct hek { |
5cbe4eec MLF |
24 | U32 hek_hash; /* hash of key */ |
25 | I32 hek_len; /* length of hash key */ | |
26 | char hek_key[1]; /* variable-length hash key */ | |
e05949c7 | 27 | /* the hash-key is \0-terminated */ |
1e54db1a JH |
28 | /* after the \0 there is a byte for flags, such as whether the key |
29 | is UTF-8 */ | |
79072805 LW |
30 | }; |
31 | ||
5cbe4eec | 32 | /* hash structure: */ |
6ee623d5 | 33 | /* This structure must match the beginning of struct xpvmg in sv.h. */ |
79072805 | 34 | struct xpvhv { |
463ee0b2 LW |
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 */ | |
6ee623d5 | 38 | IV xhv_keys; /* how many elements in the array */ |
65202027 | 39 | NV xnv_nv; /* numeric value, if any */ |
8aacddc1 | 40 | #define xhv_placeholders xnv_nv |
79072805 LW |
41 | MAGIC* xmg_magic; /* magic for scalar array */ |
42 | HV* xmg_stash; /* class package */ | |
43 | ||
79072805 LW |
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 */ | |
79072805 LW |
48 | }; |
49 | ||
5cbe4eec | 50 | /* hash a key */ |
5afd6d42 JH |
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 signed, depending on the compiler) | |
58 | * (b) catering for old code that uses a "char" | |
830b38bd | 59 | * |
504f80c1 JH |
60 | * The "hash seed" feature was added in Perl 5.8.1 to perturb the results |
61 | * to avoid "algorithmic complexity attacks". | |
830b38bd JH |
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 erl.c:perl_parse()). | |
5afd6d42 | 68 | */ |
830b38bd JH |
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 | |
504f80c1 | 75 | #endif |
bf6bd887 | 76 | #define PERL_HASH(hash,str,len) \ |
77 | STMT_START { \ | |
5afd6d42 JH |
78 | register const char *s_PeRlHaSh_tmp = str; \ |
79 | register const unsigned char *s_PeRlHaSh = (const unsigned char *)s_PeRlHaSh_tmp; \ | |
bf6bd887 | 80 | register I32 i_PeRlHaSh = len; \ |
504f80c1 | 81 | register U32 hash_PeRlHaSh = PERL_HASH_SEED; \ |
a6fe520e MLF |
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); \ | |
4fee5c71 | 89 | (hash) = (hash_PeRlHaSh + (hash_PeRlHaSh << 15)); \ |
bf6bd887 | 90 | } STMT_END |
91 | ||
3d78eb94 NC |
92 | /* Only hv.c and mod_perl should be doing this. */ |
93 | #ifdef PERL_HASH_INTERNAL_ACCESS | |
4b5190b5 NC |
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; \ | |
008fb0c0 | 99 | register U32 hash_PeRlHaSh = PL_rehash_seed; \ |
4b5190b5 NC |
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 | ||
954c1994 | 111 | /* |
ccfc67b7 JH |
112 | =head1 Hash Manipulation Functions |
113 | ||
954c1994 GS |
114 | =for apidoc AmU||HEf_SVKEY |
115 | This flag, used in the length slot of hash entries and magic structures, | |
d1be9408 | 116 | specifies the structure contains an C<SV*> pointer where a C<char*> pointer |
954c1994 GS |
117 | is to be expected. (For information only--not to be used). |
118 | ||
ccfc67b7 JH |
119 | =head1 Handy Values |
120 | ||
954c1994 GS |
121 | =for apidoc AmU||Nullhv |
122 | Null HV pointer. | |
123 | ||
ccfc67b7 JH |
124 | =head1 Hash Manipulation Functions |
125 | ||
954c1994 GS |
126 | =for apidoc Am|char*|HvNAME|HV* stash |
127 | Returns the package name of a stash. See C<SvSTASH>, C<CvSTASH>. | |
128 | ||
129 | =for apidoc Am|void*|HeKEY|HE* he | |
130 | Returns the actual pointer stored in the key slot of the hash entry. The | |
131 | pointer may be either C<char*> or C<SV*>, depending on the value of | |
132 | C<HeKLEN()>. Can be assigned to. The C<HePV()> or C<HeSVKEY()> macros are | |
133 | usually preferable for finding the value of a key. | |
134 | ||
135 | =for apidoc Am|STRLEN|HeKLEN|HE* he | |
136 | If this is negative, and amounts to C<HEf_SVKEY>, it indicates the entry | |
137 | holds an C<SV*> key. Otherwise, holds the actual length of the key. Can | |
138 | be assigned to. The C<HePV()> macro is usually preferable for finding key | |
139 | lengths. | |
140 | ||
141 | =for apidoc Am|SV*|HeVAL|HE* he | |
142 | Returns the value slot (type C<SV*>) stored in the hash entry. | |
143 | ||
144 | =for apidoc Am|U32|HeHASH|HE* he | |
145 | Returns the computed hash stored in the hash entry. | |
146 | ||
147 | =for apidoc Am|char*|HePV|HE* he|STRLEN len | |
148 | Returns the key slot of the hash entry as a C<char*> value, doing any | |
149 | necessary dereferencing of possibly C<SV*> keys. The length of the string | |
150 | is placed in C<len> (this is a macro, so do I<not> use C<&len>). If you do | |
151 | not care about what the length of the key is, you may use the global | |
152 | variable C<PL_na>, though this is rather less efficient than using a local | |
153 | variable. Remember though, that hash keys in perl are free to contain | |
154 | embedded nulls, so using C<strlen()> or similar is not a good way to find | |
155 | the length of hash keys. This is very similar to the C<SvPV()> macro | |
156 | described elsewhere in this document. | |
157 | ||
158 | =for apidoc Am|SV*|HeSVKEY|HE* he | |
159 | Returns the key as an C<SV*>, or C<Nullsv> if the hash entry does not | |
160 | contain an C<SV*> key. | |
161 | ||
162 | =for apidoc Am|SV*|HeSVKEY_force|HE* he | |
163 | Returns the key as an C<SV*>. Will create and return a temporary mortal | |
164 | C<SV*> if the hash entry contains only a C<char*> key. | |
165 | ||
166 | =for apidoc Am|SV*|HeSVKEY_set|HE* he|SV* sv | |
167 | Sets the key to a given C<SV*>, taking care to set the appropriate flags to | |
168 | indicate the presence of an C<SV*> key, and returns the same | |
169 | C<SV*>. | |
170 | ||
171 | =cut | |
172 | */ | |
bf6bd887 | 173 | |
bf5b86ae | 174 | /* these hash entry flags ride on hent_klen (for use only in magic/tied HVs) */ |
d1be9408 | 175 | #define HEf_SVKEY -2 /* hent_key is an SV* */ |
bf6bd887 | 176 | |
177 | ||
79072805 | 178 | #define Nullhv Null(HV*) |
4efcf9a2 | 179 | #define HvARRAY(hv) (*(HE***)&((XPVHV*) SvANY(hv))->xhv_array) |
79072805 | 180 | #define HvFILL(hv) ((XPVHV*) SvANY(hv))->xhv_fill |
463ee0b2 | 181 | #define HvMAX(hv) ((XPVHV*) SvANY(hv))->xhv_max |
79072805 LW |
182 | #define HvRITER(hv) ((XPVHV*) SvANY(hv))->xhv_riter |
183 | #define HvEITER(hv) ((XPVHV*) SvANY(hv))->xhv_eiter | |
184 | #define HvPMROOT(hv) ((XPVHV*) SvANY(hv))->xhv_pmroot | |
185 | #define HvNAME(hv) ((XPVHV*) SvANY(hv))->xhv_name | |
a0d0e21e | 186 | |
8aacddc1 NIS |
187 | /* the number of keys (including any placeholers) */ |
188 | #define XHvTOTALKEYS(xhv) ((xhv)->xhv_keys) | |
189 | ||
190 | /* The number of placeholders in the enumerated-keys hash */ | |
205c8ad3 | 191 | #define XHvPLACEHOLDERS(xhv) ((xhv)->xhv_placeholders) |
8aacddc1 | 192 | |
dd2710a1 VK |
193 | /* the number of keys that exist() (i.e. excluding placeholders) */ |
194 | #define XHvUSEDKEYS(xhv) (XHvTOTALKEYS(xhv) - (IV)XHvPLACEHOLDERS(xhv)) | |
8aacddc1 NIS |
195 | |
196 | /* | |
197 | * HvKEYS gets the number of keys that actually exist(), and is provided | |
198 | * for backwards compatibility with old XS code. The core uses HvUSEDKEYS | |
199 | * (keys, excluding placeholdes) and HvTOTALKEYS (including placeholders) | |
200 | */ | |
201 | #define HvKEYS(hv) XHvUSEDKEYS((XPVHV*) SvANY(hv)) | |
202 | #define HvUSEDKEYS(hv) XHvUSEDKEYS((XPVHV*) SvANY(hv)) | |
203 | #define HvTOTALKEYS(hv) XHvTOTALKEYS((XPVHV*) SvANY(hv)) | |
204 | #define HvPLACEHOLDERS(hv) XHvPLACEHOLDERS((XPVHV*) SvANY(hv)) | |
205 | ||
bf6bd887 | 206 | #define HvSHAREKEYS(hv) (SvFLAGS(hv) & SVphv_SHAREKEYS) |
207 | #define HvSHAREKEYS_on(hv) (SvFLAGS(hv) |= SVphv_SHAREKEYS) | |
208 | #define HvSHAREKEYS_off(hv) (SvFLAGS(hv) &= ~SVphv_SHAREKEYS) | |
209 | ||
19692e8d NC |
210 | /* This is an optimisation flag. It won't be set if all hash keys have a 0 |
211 | * flag. Currently the only flags relate to utf8. | |
212 | * Hence it won't be set if all keys are 8 bit only. It will be set if any key | |
213 | * is utf8 (including 8 bit keys that were entered as utf8, and need upgrading | |
214 | * when retrieved during iteration. It may still be set when there are no longer | |
215 | * any utf8 keys. | |
fdcd69b6 | 216 | * See HVhek_ENABLEHVKFLAGS for the trigger. |
19692e8d NC |
217 | */ |
218 | #define HvHASKFLAGS(hv) (SvFLAGS(hv) & SVphv_HASKFLAGS) | |
219 | #define HvHASKFLAGS_on(hv) (SvFLAGS(hv) |= SVphv_HASKFLAGS) | |
220 | #define HvHASKFLAGS_off(hv) (SvFLAGS(hv) &= ~SVphv_HASKFLAGS) | |
574c8022 | 221 | |
bf5b86ae GS |
222 | #define HvLAZYDEL(hv) (SvFLAGS(hv) & SVphv_LAZYDEL) |
223 | #define HvLAZYDEL_on(hv) (SvFLAGS(hv) |= SVphv_LAZYDEL) | |
224 | #define HvLAZYDEL_off(hv) (SvFLAGS(hv) &= ~SVphv_LAZYDEL) | |
225 | ||
4b5190b5 NC |
226 | #define HvREHASH(hv) (SvFLAGS(hv) & SVphv_REHASH) |
227 | #define HvREHASH_on(hv) (SvFLAGS(hv) |= SVphv_REHASH) | |
228 | #define HvREHASH_off(hv) (SvFLAGS(hv) &= ~SVphv_REHASH) | |
229 | ||
a0d0e21e LW |
230 | /* Maybe amagical: */ |
231 | /* #define HV_AMAGICmb(hv) (SvFLAGS(hv) & (SVpgv_badAM | SVpgv_AM)) */ | |
232 | ||
233 | #define HV_AMAGIC(hv) (SvFLAGS(hv) & SVpgv_AM) | |
234 | #define HV_AMAGIC_on(hv) (SvFLAGS(hv) |= SVpgv_AM) | |
235 | #define HV_AMAGIC_off(hv) (SvFLAGS(hv) &= ~SVpgv_AM) | |
236 | ||
237 | /* | |
238 | #define HV_AMAGICbad(hv) (SvFLAGS(hv) & SVpgv_badAM) | |
239 | #define HV_badAMAGIC_on(hv) (SvFLAGS(hv) |= SVpgv_badAM) | |
240 | #define HV_badAMAGIC_off(hv) (SvFLAGS(hv) &= ~SVpgv_badAM) | |
241 | */ | |
bf6bd887 | 242 | |
243 | #define Nullhe Null(HE*) | |
244 | #define HeNEXT(he) (he)->hent_next | |
ff68c719 | 245 | #define HeKEY_hek(he) (he)->hent_hek |
246 | #define HeKEY(he) HEK_KEY(HeKEY_hek(he)) | |
bbce6d69 | 247 | #define HeKEY_sv(he) (*(SV**)HeKEY(he)) |
ff68c719 | 248 | #define HeKLEN(he) HEK_LEN(HeKEY_hek(he)) |
da58a35d | 249 | #define HeKUTF8(he) HEK_UTF8(HeKEY_hek(he)) |
19692e8d | 250 | #define HeKWASUTF8(he) HEK_WASUTF8(HeKEY_hek(he)) |
4b5190b5 | 251 | #define HeKREHASH(he) HEK_REHASH(HeKEY_hek(he)) |
da58a35d | 252 | #define HeKLEN_UTF8(he) (HeKUTF8(he) ? -HeKLEN(he) : HeKLEN(he)) |
19692e8d | 253 | #define HeKFLAGS(he) HEK_FLAGS(HeKEY_hek(he)) |
bf6bd887 | 254 | #define HeVAL(he) (he)->hent_val |
ff68c719 | 255 | #define HeHASH(he) HEK_HASH(HeKEY_hek(he)) |
1e422769 | 256 | #define HePV(he,lp) ((HeKLEN(he) == HEf_SVKEY) ? \ |
257 | SvPV(HeKEY_sv(he),lp) : \ | |
258 | (((lp = HeKLEN(he)) >= 0) ? \ | |
259 | HeKEY(he) : Nullch)) | |
260 | ||
bbce6d69 | 261 | #define HeSVKEY(he) ((HeKEY(he) && \ |
262 | HeKLEN(he) == HEf_SVKEY) ? \ | |
263 | HeKEY_sv(he) : Nullsv) | |
264 | ||
265 | #define HeSVKEY_force(he) (HeKEY(he) ? \ | |
266 | ((HeKLEN(he) == HEf_SVKEY) ? \ | |
267 | HeKEY_sv(he) : \ | |
79cb57f6 | 268 | sv_2mortal(newSVpvn(HeKEY(he), \ |
bbce6d69 | 269 | HeKLEN(he)))) : \ |
3280af22 | 270 | &PL_sv_undef) |
1e422769 | 271 | #define HeSVKEY_set(he,sv) ((HeKLEN(he) = HEf_SVKEY), (HeKEY_sv(he) = sv)) |
bbce6d69 | 272 | |
ff68c719 | 273 | #define Nullhek Null(HEK*) |
71be2cbc | 274 | #define HEK_BASESIZE STRUCT_OFFSET(HEK, hek_key[0]) |
ff68c719 | 275 | #define HEK_HASH(hek) (hek)->hek_hash |
276 | #define HEK_LEN(hek) (hek)->hek_len | |
277 | #define HEK_KEY(hek) (hek)->hek_key | |
19692e8d NC |
278 | #define HEK_FLAGS(hek) (*((unsigned char *)(HEK_KEY(hek))+HEK_LEN(hek)+1)) |
279 | ||
280 | #define HVhek_UTF8 0x01 /* Key is utf8 encoded. */ | |
281 | #define HVhek_WASUTF8 0x02 /* Key is bytes here, but was supplied as utf8. */ | |
4b5190b5 | 282 | #define HVhek_REHASH 0x04 /* This key is in an hv using a custom HASH . */ |
19692e8d | 283 | #define HVhek_FREEKEY 0x100 /* Internal flag to say key is malloc()ed. */ |
e16e2ff8 NC |
284 | #define HVhek_PLACEHOLD 0x200 /* Internal flag to create placeholder. |
285 | * (may change, but Storable is a core module) */ | |
19692e8d NC |
286 | #define HVhek_MASK 0xFF |
287 | ||
fdcd69b6 NC |
288 | /* Which flags enable HvHASKFLAGS? Somewhat a hack on a hack, as |
289 | HVhek_REHASH is only needed because the rehash flag has to be duplicated | |
290 | into all keys as hv_iternext has no access to the hash flags. At this | |
291 | point Storable's tests get upset, because sometimes hashes are "keyed" | |
292 | and sometimes not, depending on the order of data insertion, and whether | |
293 | it triggered rehashing. So currently HVhek_REHAS is exempt. | |
294 | */ | |
295 | ||
296 | #define HVhek_ENABLEHVKFLAGS (HVhek_MASK - HVhek_REHASH) | |
297 | ||
19692e8d NC |
298 | #define HEK_UTF8(hek) (HEK_FLAGS(hek) & HVhek_UTF8) |
299 | #define HEK_UTF8_on(hek) (HEK_FLAGS(hek) |= HVhek_UTF8) | |
300 | #define HEK_UTF8_off(hek) (HEK_FLAGS(hek) &= ~HVhek_UTF8) | |
301 | #define HEK_WASUTF8(hek) (HEK_FLAGS(hek) & HVhek_WASUTF8) | |
302 | #define HEK_WASUTF8_on(hek) (HEK_FLAGS(hek) |= HVhek_WASUTF8) | |
303 | #define HEK_WASUTF8_off(hek) (HEK_FLAGS(hek) &= ~HVhek_WASUTF8) | |
4b5190b5 NC |
304 | #define HEK_REHASH(hek) (HEK_FLAGS(hek) & HVhek_REHASH) |
305 | #define HEK_REHASH_on(hek) (HEK_FLAGS(hek) |= HVhek_REHASH) | |
d18c6117 | 306 | |
5cbe4eec | 307 | /* calculate HV array allocation */ |
d18c6117 GS |
308 | #if defined(STRANGE_MALLOC) || defined(MYMALLOC) |
309 | # define PERL_HV_ARRAY_ALLOC_BYTES(size) ((size) * sizeof(HE*)) | |
310 | #else | |
311 | # define MALLOC_OVERHEAD 16 | |
312 | # define PERL_HV_ARRAY_ALLOC_BYTES(size) \ | |
313 | (((size) < 64) \ | |
314 | ? (size) * sizeof(HE*) \ | |
315 | : (size) * sizeof(HE*) * 2 - MALLOC_OVERHEAD) | |
316 | #endif | |
37d85e3a | 317 | |
e16e2ff8 NC |
318 | /* Flags for hv_iternext_flags. */ |
319 | #define HV_ITERNEXT_WANTPLACEHOLDERS 0x01 /* Don't skip placeholders. */ | |
320 | ||
37d85e3a JH |
321 | /* available as a function in hv.c */ |
322 | #define Perl_sharepvn(sv, len, hash) HEK_KEY(share_hek(sv, len, hash)) | |
323 | #define sharepvn(sv, len, hash) Perl_sharepvn(sv, len, hash) |