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9636b49c | 1 | /* Copyright (C) 1995,1996,1997, 2000, 2001 Free Software Foundation, Inc. |
0f2d19dd JB |
2 | * |
3 | * This program is free software; you can redistribute it and/or modify | |
4 | * it under the terms of the GNU General Public License as published by | |
5 | * the Free Software Foundation; either version 2, or (at your option) | |
6 | * any later version. | |
7 | * | |
8 | * This program is distributed in the hope that it will be useful, | |
9 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
11 | * GNU General Public License for more details. | |
12 | * | |
13 | * You should have received a copy of the GNU General Public License | |
14 | * along with this software; see the file COPYING. If not, write to | |
82892bed JB |
15 | * the Free Software Foundation, Inc., 59 Temple Place, Suite 330, |
16 | * Boston, MA 02111-1307 USA | |
0f2d19dd JB |
17 | * |
18 | * As a special exception, the Free Software Foundation gives permission | |
19 | * for additional uses of the text contained in its release of GUILE. | |
20 | * | |
21 | * The exception is that, if you link the GUILE library with other files | |
22 | * to produce an executable, this does not by itself cause the | |
23 | * resulting executable to be covered by the GNU General Public License. | |
24 | * Your use of that executable is in no way restricted on account of | |
25 | * linking the GUILE library code into it. | |
26 | * | |
27 | * This exception does not however invalidate any other reasons why | |
28 | * the executable file might be covered by the GNU General Public License. | |
29 | * | |
30 | * This exception applies only to the code released by the | |
31 | * Free Software Foundation under the name GUILE. If you copy | |
32 | * code from other Free Software Foundation releases into a copy of | |
33 | * GUILE, as the General Public License permits, the exception does | |
34 | * not apply to the code that you add in this way. To avoid misleading | |
35 | * anyone as to the status of such modified files, you must delete | |
36 | * this exception notice from them. | |
37 | * | |
38 | * If you write modifications of your own for GUILE, it is your choice | |
39 | * whether to permit this exception to apply to your modifications. | |
82892bed | 40 | * If you do not wish that, delete this exception notice. */ |
1bbd0b84 GB |
41 | |
42 | /* Software engineering face-lift by Greg J. Badros, 11-Dec-1999, | |
43 | gjb@cs.washington.edu, http://www.cs.washington.edu/homes/gjb */ | |
44 | ||
0f2d19dd JB |
45 | \f |
46 | ||
a0599745 MD |
47 | #include "libguile/_scm.h" |
48 | #include "libguile/chars.h" | |
49 | #include "libguile/ports.h" | |
a002f1a2 DH |
50 | #include "libguile/strings.h" |
51 | #include "libguile/symbols.h" | |
a0599745 | 52 | #include "libguile/vectors.h" |
0f2d19dd | 53 | |
a0599745 MD |
54 | #include "libguile/validate.h" |
55 | #include "libguile/hash.h" | |
0f2d19dd JB |
56 | \f |
57 | ||
58 | #ifndef floor | |
59 | extern double floor(); | |
60 | #endif | |
61 | ||
1cc91f1b | 62 | |
ba393257 DH |
63 | unsigned long |
64 | scm_string_hash (const unsigned char *str, scm_sizet len) | |
65 | { | |
66 | if (len > 5) | |
67 | { | |
68 | scm_sizet i = 5; | |
69 | unsigned long h = 264; | |
70 | while (i--) | |
9636b49c | 71 | h = (h << 8) + (unsigned) str[h % len]; |
ba393257 DH |
72 | return h; |
73 | } | |
74 | else | |
75 | { | |
76 | scm_sizet i = len; | |
77 | unsigned long h = 0; | |
78 | while (i) | |
9636b49c | 79 | h = (h << 8) + (unsigned) str[--i]; |
ba393257 DH |
80 | return h; |
81 | } | |
82 | } | |
83 | ||
84 | ||
dba97178 DH |
85 | /* Dirk:FIXME:: why downcase for characters? (2x: scm_hasher, scm_ihashv) */ |
86 | /* Dirk:FIXME:: scm_hasher could be made static. */ | |
87 | ||
88 | ||
0f2d19dd | 89 | unsigned long |
1bbd0b84 | 90 | scm_hasher(SCM obj, unsigned long n, scm_sizet d) |
0f2d19dd | 91 | { |
dba97178 DH |
92 | switch (SCM_ITAG3 (obj)) { |
93 | case scm_tc3_int_1: | |
94 | case scm_tc3_int_2: | |
94a5efac | 95 | return SCM_INUM(obj) % n; /* SCM_INUMP(obj) */ |
dba97178 DH |
96 | case scm_tc3_imm24: |
97 | if (SCM_CHARP(obj)) | |
7866a09b | 98 | return (unsigned)(scm_downcase(SCM_CHAR(obj))) % n; |
dba97178 | 99 | switch (SCM_UNPACK (obj)) { |
0f2d19dd | 100 | #ifndef SICP |
dba97178 | 101 | case SCM_EOL: |
94a5efac GB |
102 | d = 256; |
103 | break; | |
0f2d19dd | 104 | #endif |
dba97178 | 105 | case SCM_BOOL_T: |
94a5efac GB |
106 | d = 257; |
107 | break; | |
dba97178 | 108 | case SCM_BOOL_F: |
94a5efac GB |
109 | d = 258; |
110 | break; | |
dba97178 | 111 | case SCM_EOF_VAL: |
94a5efac GB |
112 | d = 259; |
113 | break; | |
114 | default: | |
115 | d = 263; /* perhaps should be error */ | |
0f2d19dd JB |
116 | } |
117 | return d % n; | |
94a5efac GB |
118 | default: |
119 | return 263 % n; /* perhaps should be error */ | |
dba97178 | 120 | case scm_tc3_cons: |
0f2d19dd | 121 | switch SCM_TYP7(obj) { |
94a5efac GB |
122 | default: |
123 | return 263 % n; | |
0f2d19dd JB |
124 | case scm_tc7_smob: |
125 | switch SCM_TYP16(obj) { | |
950cc72b | 126 | case scm_tc16_big: |
94a5efac GB |
127 | return SCM_INUM(scm_modulo(obj, SCM_MAKINUM(n))); |
128 | default: | |
129 | return 263 % n; | |
950cc72b MD |
130 | case scm_tc16_real: |
131 | { | |
eb42e2f0 | 132 | double r = SCM_REAL_VALUE(obj); |
0f2d19dd JB |
133 | if (floor(r)==r) { |
134 | obj = scm_inexact_to_exact (obj); | |
135 | if SCM_IMP(obj) return SCM_INUM(obj) % n; | |
94a5efac | 136 | return SCM_INUM(scm_modulo(obj, SCM_MAKINUM(n))); |
0f2d19dd JB |
137 | } |
138 | } | |
950cc72b | 139 | case scm_tc16_complex: |
0f2d19dd | 140 | obj = scm_number_to_string(obj, SCM_MAKINUM(10)); |
0f2d19dd | 141 | } |
0f2d19dd | 142 | case scm_tc7_string: |
0f2d19dd | 143 | case scm_tc7_substring: |
34f0f2b8 | 144 | return scm_string_hash (SCM_STRING_UCHARS (obj), SCM_STRING_LENGTH (obj)) % n; |
28b06554 DH |
145 | case scm_tc7_symbol: |
146 | return SCM_SYMBOL_HASH (obj) % n; | |
0f2d19dd JB |
147 | case scm_tc7_wvect: |
148 | case scm_tc7_vector: | |
149 | { | |
bfa974f0 | 150 | scm_sizet len = SCM_VECTOR_LENGTH(obj); |
0f2d19dd JB |
151 | SCM *data = SCM_VELTS(obj); |
152 | if (len>5) | |
153 | { | |
154 | scm_sizet i = d/2; | |
155 | unsigned long h = 1; | |
156 | while (i--) h = ((h<<8) + (scm_hasher(data[h % len], n, 2))) % n; | |
157 | return h; | |
158 | } | |
159 | else | |
160 | { | |
161 | scm_sizet i = len; | |
162 | unsigned long h = (n)-1; | |
163 | while (i--) h = ((h<<8) + (scm_hasher(data[i], n, d/len))) % n; | |
164 | return h; | |
165 | } | |
166 | } | |
94a5efac GB |
167 | case scm_tcs_cons_imcar: |
168 | case scm_tcs_cons_nimcar: | |
0f2d19dd JB |
169 | if (d) return (scm_hasher(SCM_CAR(obj), n, d/2)+scm_hasher(SCM_CDR(obj), n, d/2)) % n; |
170 | else return 1; | |
171 | case scm_tc7_port: | |
206d3de3 | 172 | return ((SCM_RDNG & SCM_CELL_WORD_0 (obj)) ? 260 : 261) % n; |
94a5efac | 173 | case scm_tcs_closures: |
94a5efac | 174 | case scm_tcs_subrs: |
0f2d19dd JB |
175 | return 262 % n; |
176 | } | |
177 | } | |
178 | } | |
179 | ||
180 | ||
181 | \f | |
182 | ||
1cc91f1b | 183 | |
0f2d19dd | 184 | unsigned int |
1bbd0b84 | 185 | scm_ihashq (SCM obj, unsigned int n) |
0f2d19dd | 186 | { |
54778cd3 | 187 | return (SCM_UNPACK (obj) >> 1) % n; |
0f2d19dd JB |
188 | } |
189 | ||
190 | ||
3b3b36dd | 191 | SCM_DEFINE (scm_hashq, "hashq", 2, 0, 0, |
94a5efac | 192 | (SCM key, SCM size), |
5352393c MG |
193 | "Determine a hash value for @var{key} that is suitable for\n" |
194 | "lookups in a hashtable of size @var{size}, where @code{eq?} is\n" | |
195 | "used as the equality predicate. The function returns an\n" | |
196 | "integer in the range 0 to @var{size} - 1. Note that\n" | |
197 | "@code{hashq} may use internal addresses. Thus two calls to\n" | |
198 | "hashq where the keys are @code{eq?} are not guaranteed to\n" | |
199 | "deliver the same value if the key object gets garbage collected\n" | |
200 | "in between. This can happen, for example with symbols:\n" | |
201 | "@code{(hashq 'foo n) (gc) (hashq 'foo n)} may produce two\n" | |
202 | "different values, since @code{foo} will be garbage collected.") | |
1bbd0b84 | 203 | #define FUNC_NAME s_scm_hashq |
0f2d19dd | 204 | { |
94a5efac GB |
205 | SCM_VALIDATE_INUM_MIN (2, size, 0); |
206 | return SCM_MAKINUM (scm_ihashq (key, SCM_INUM (size))); | |
0f2d19dd | 207 | } |
1bbd0b84 | 208 | #undef FUNC_NAME |
0f2d19dd JB |
209 | |
210 | ||
211 | \f | |
212 | ||
1cc91f1b | 213 | |
0f2d19dd | 214 | unsigned int |
1bbd0b84 | 215 | scm_ihashv (SCM obj, unsigned int n) |
0f2d19dd | 216 | { |
7866a09b GB |
217 | if (SCM_CHARP(obj)) |
218 | return ((unsigned int)(scm_downcase(SCM_CHAR(obj)))) % n; /* downcase!?!! */ | |
0f2d19dd | 219 | |
0c95b57d | 220 | if (SCM_NUMP(obj)) |
0f2d19dd JB |
221 | return (unsigned int) scm_hasher(obj, n, 10); |
222 | else | |
54778cd3 | 223 | return SCM_UNPACK (obj) % n; |
0f2d19dd JB |
224 | } |
225 | ||
226 | ||
3b3b36dd | 227 | SCM_DEFINE (scm_hashv, "hashv", 2, 0, 0, |
94a5efac | 228 | (SCM key, SCM size), |
5352393c MG |
229 | "Determine a hash value for @var{key} that is suitable for\n" |
230 | "lookups in a hashtable of size @var{size}, where @code{eqv?} is\n" | |
231 | "used as the equality predicate. The function returns an\n" | |
232 | "integer in the range 0 to @var{size} - 1. Note that\n" | |
233 | "@code{(hashv key)} may use internal addresses. Thus two calls\n" | |
234 | "to hashv where the keys are @code{eqv?} are not guaranteed to\n" | |
235 | "deliver the same value if the key object gets garbage collected\n" | |
236 | "in between. This can happen, for example with symbols:\n" | |
237 | "@code{(hashv 'foo n) (gc) (hashv 'foo n)} may produce two\n" | |
238 | "different values, since @code{foo} will be garbage collected.") | |
1bbd0b84 | 239 | #define FUNC_NAME s_scm_hashv |
0f2d19dd | 240 | { |
94a5efac GB |
241 | SCM_VALIDATE_INUM_MIN (2, size, 0); |
242 | return SCM_MAKINUM (scm_ihashv (key, SCM_INUM (size))); | |
0f2d19dd | 243 | } |
1bbd0b84 | 244 | #undef FUNC_NAME |
0f2d19dd JB |
245 | |
246 | ||
247 | \f | |
248 | ||
1cc91f1b | 249 | |
0f2d19dd | 250 | unsigned int |
1bbd0b84 | 251 | scm_ihash (SCM obj, unsigned int n) |
0f2d19dd JB |
252 | { |
253 | return (unsigned int)scm_hasher (obj, n, 10); | |
254 | } | |
255 | ||
3b3b36dd | 256 | SCM_DEFINE (scm_hash, "hash", 2, 0, 0, |
94a5efac | 257 | (SCM key, SCM size), |
5352393c MG |
258 | "Determine a hash value for @var{key} that is suitable for\n" |
259 | "lookups in a hashtable of size @var{size}, where @code{equal?}\n" | |
260 | "is used as the equality predicate. The function returns an\n" | |
261 | "integer in the range 0 to @var{size} - 1.") | |
1bbd0b84 | 262 | #define FUNC_NAME s_scm_hash |
0f2d19dd | 263 | { |
94a5efac GB |
264 | SCM_VALIDATE_INUM_MIN (2, size, 0); |
265 | return SCM_MAKINUM (scm_ihash (key, SCM_INUM (size))); | |
0f2d19dd | 266 | } |
1bbd0b84 | 267 | #undef FUNC_NAME |
0f2d19dd JB |
268 | |
269 | ||
270 | \f | |
271 | ||
1cc91f1b | 272 | |
0f2d19dd JB |
273 | void |
274 | scm_init_hash () | |
0f2d19dd | 275 | { |
8dc9439f | 276 | #ifndef SCM_MAGIC_SNARFER |
a0599745 | 277 | #include "libguile/hash.x" |
8dc9439f | 278 | #endif |
0f2d19dd JB |
279 | } |
280 | ||
89e00824 ML |
281 | |
282 | /* | |
283 | Local Variables: | |
284 | c-file-style: "gnu" | |
285 | End: | |
286 | */ |