Line data Source code
1 : /* Copyright (C) 2000 The PARI group.
2 :
3 : This file is part of the PARI/GP package.
4 :
5 : PARI/GP is free software; you can redistribute it and/or modify it under the
6 : terms of the GNU General Public License as published by the Free Software
7 : Foundation; either version 2 of the License, or (at your option) any later
8 : version. It is distributed in the hope that it will be useful, but WITHOUT
9 : ANY WARRANTY WHATSOEVER.
10 :
11 : Check the License for details. You should have received a copy of it, along
12 : with the package; see the file 'COPYING'. If not, write to the Free Software
13 : Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. */
14 : #include "pari.h"
15 : #include "paripriv.h"
16 :
17 : /********************************************************************/
18 : /* */
19 : /* GENERAL HASHTABLES */
20 : /* */
21 : /********************************************************************/
22 : /* http://planetmath.org/encyclopedia/GoodHashTablePrimes.html */
23 : static const ulong hashprimes[] = {
24 : 53, 97, 193, 389, 769, 1543, 3079, 6151, 12289, 24593, 49157, 98317, 196613,
25 : 393241, 786433, 1572869, 3145739, 6291469, 12582917, 25165843, 50331653,
26 : 100663319, 201326611, 402653189, 805306457, 1610612741
27 : };
28 : static const int hashprimes_len = numberof(hashprimes);
29 :
30 : INLINE void
31 40568 : setlen(hashtable *h, ulong len) {
32 40568 : h->maxnb = (ulong)ceil(len * 0.65);
33 40568 : h->len = len;
34 40568 : }
35 :
36 : static int
37 37455 : get_prime_index(ulong len)
38 : {
39 : int i;
40 60180 : for (i=0; i < hashprimes_len; i++)
41 60180 : if (hashprimes[i] > len) return i;
42 0 : pari_err_OVERFLOW("hash table [too large]");
43 : return -1; /* LCOV_EXCL_LINE */
44 : }
45 :
46 : /* link hashentry e to hashtable h, setting e->hash / e->next */
47 : INLINE void
48 1416407 : hash_link2(hashtable *h, hashentry *e, ulong hash)
49 : {
50 : ulong index;
51 1416407 : e->hash = hash; index = e->hash % h->len;
52 1416407 : e->next = h->table[index]; h->table[index] = e;
53 1416407 : }
54 : INLINE void
55 16475 : hash_link(hashtable *h, hashentry *e) { hash_link2(h,e,h->hash(e->key));}
56 :
57 : hashtable *
58 27445 : hash_create(ulong minsize, ulong (*hash)(void*), int (*eq)(void*,void*),
59 : int use_stack)
60 : {
61 27445 : int i = get_prime_index(minsize);
62 27445 : ulong len = hashprimes[i];
63 : hashtable *h;
64 :
65 27445 : if (use_stack)
66 : {
67 23788 : h = (hashtable*)stack_malloc(sizeof(hashtable));
68 23788 : h->table = (hashentry**)stack_calloc(len * sizeof(hashentry*));
69 23788 : h->use_stack = 1;
70 : }
71 : else
72 : {
73 3657 : h = (hashtable*)pari_malloc(sizeof(hashtable));
74 3657 : h->table = (hashentry**)pari_calloc(len * sizeof(hashentry*));
75 3657 : h->use_stack = 0;
76 : }
77 27445 : h->pindex = i;
78 27445 : h->nb = 0;
79 27445 : h->hash = hash;
80 27445 : h->eq = eq;
81 27445 : setlen(h, len); return h;
82 : }
83 : static ulong
84 648957 : hash_id(void *x) { return (ulong)x; }
85 : static int
86 303332 : eq_id(void *x, void *y) { return x == y; }
87 : hashtable *
88 1057 : hash_create_ulong(ulong s, long stack)
89 1057 : { return hash_create(s, &hash_id, &eq_id, stack); }
90 :
91 : void
92 10010 : hash_init(hashtable *h, ulong minsize, ulong (*hash)(void*),
93 : int (*eq)(void*,void*), int use_stack)
94 : {
95 10010 : int i = get_prime_index(minsize);
96 10010 : ulong len = hashprimes[i];
97 10010 : if (use_stack)
98 10010 : h->table = (hashentry**)stack_calloc(len * sizeof(hashentry*));
99 : else
100 0 : h->table = (hashentry**)pari_calloc(len * sizeof(hashentry*));
101 10010 : h->use_stack = use_stack;
102 10010 : h->pindex = i;
103 10010 : h->nb = 0;
104 10010 : h->hash = hash;
105 10010 : h->eq = eq;
106 10010 : setlen(h, len);
107 10010 : }
108 :
109 : void
110 9005 : hash_init_GEN(hashtable *h, ulong minsize, int (*eq)(GEN,GEN), int use_stack)
111 9005 : { hash_init(h, minsize,(ulong (*)(void*)) hash_GEN,
112 : (int (*)(void*,void*)) eq, use_stack);
113 9005 : }
114 :
115 : void
116 1005 : hash_init_ulong(hashtable *h, ulong minsize, int use_stack)
117 1005 : { hash_init(h, minsize,hash_id, eq_id, use_stack); }
118 :
119 : void
120 1399932 : hash_insert2(hashtable *h, void *k, void *v, ulong hash)
121 : {
122 : hashentry *e;
123 : ulong index;
124 :
125 1399932 : if (h->use_stack)
126 1390992 : e = (hashentry*) stack_malloc(sizeof(hashentry));
127 : else
128 8940 : e = (hashentry*) pari_malloc(sizeof(hashentry));
129 :
130 1399932 : if (++(h->nb) > h->maxnb && h->pindex < hashprimes_len-1)
131 : { /* double table size */
132 3113 : ulong i, newlen = hashprimes[++(h->pindex)];
133 : hashentry *E, **newtable;
134 3113 : if (h->use_stack)
135 3113 : newtable = (hashentry**)stack_calloc(newlen*sizeof(hashentry*));
136 : else
137 0 : newtable = (hashentry**)pari_calloc(newlen*sizeof(hashentry*));
138 1243426 : for (i = 0; i < h->len; i++)
139 2048111 : while ( (E = h->table[i]) )
140 : {
141 807798 : h->table[i] = E->next;
142 807798 : index = E->hash % newlen;
143 807798 : E->next = newtable[index];
144 807798 : newtable[index] = E;
145 : }
146 3113 : if (!h->use_stack) pari_free(h->table);
147 3113 : h->table = newtable;
148 3113 : setlen(h, newlen);
149 : }
150 1399932 : e->key = k;
151 1399932 : e->val = v; hash_link2(h, e, hash);
152 1399932 : }
153 : void
154 572501 : hash_insert(hashtable *h, void *k, void *v)
155 572501 : { hash_insert2(h,k,v,h->hash(k)); }
156 :
157 : void
158 54690 : hash_insert_long(hashtable *h, void *k, long v)
159 54690 : { hash_insert2(h,k,(void*)v,h->hash(k)); }
160 :
161 : /* the key 'k' may correspond to different values in the hash, return
162 : * one satisfying the selection callback */
163 : hashentry *
164 70 : hash_select(hashtable *h, void *k, void *E,int(*select)(void *,hashentry *))
165 : {
166 70 : ulong hash = h->hash(k);
167 70 : hashentry *e = h->table[ hash % h->len ];
168 140 : while (e)
169 : {
170 91 : if (hash == e->hash && h->eq(k, e->key) && select(E,e)) return e;
171 70 : e = e->next;
172 : }
173 49 : return NULL;
174 : }
175 :
176 : GEN
177 2215 : hash_keys(hashtable *h)
178 : {
179 2215 : long k = 1;
180 : ulong i;
181 2215 : GEN v = cgetg(h->nb+1, t_VECSMALL);
182 781814 : for (i = 0; i < h->len; i++)
183 : {
184 779599 : hashentry *e = h->table[i];
185 1017691 : while (e) { v[k++] = (long)e->key; e = e->next; }
186 : }
187 2215 : return v;
188 : }
189 : GEN
190 1946 : hash_values(hashtable *h)
191 : {
192 1946 : long k = 1;
193 : ulong i;
194 1946 : GEN v = cgetg(h->nb+1, t_VECSMALL);
195 377524 : for (i = 0; i < h->len; i++)
196 : {
197 375578 : hashentry *e = h->table[i];
198 383361 : while (e) { v[k++] = (long)e->val; e = e->next; }
199 : }
200 1946 : return v;
201 : }
202 :
203 : /* assume hash = h->hash(k) */
204 : hashentry *
205 3190309 : hash_search2(hashtable *h, void *k, ulong hash)
206 : {
207 3190309 : hashentry *e = h->table[ hash % h->len ];
208 4036909 : while (e)
209 : {
210 2794711 : if (hash == e->hash && h->eq(k, e->key)) return e;
211 846600 : e = e->next;
212 : }
213 1242198 : return NULL; /* not found */
214 : }
215 : /* returns entry attached to key k or NULL */
216 : hashentry *
217 1655591 : hash_search(hashtable *h, void *k)
218 : {
219 1655591 : if (h->nb == 0) return NULL;
220 1650333 : return hash_search2(h, k, h->hash(k));
221 : }
222 :
223 : int
224 335474 : hash_haskey_long(hashtable *h, void *k, long *v)
225 : {
226 335474 : hashentry * e = hash_search(h, k);
227 335474 : if (e) { *v = (long) e->val; return 1; }
228 48103 : else return 0;
229 : }
230 :
231 : GEN
232 151919 : hash_haskey_GEN(hashtable *h, void *k)
233 : {
234 151919 : hashentry * e = hash_search(h, k);
235 151919 : return e ? (GEN) e->val: NULL;
236 : }
237 :
238 : hashentry *
239 2954 : hash_remove_select(hashtable *h, void *k, void *E,
240 : int (*select)(void*,hashentry*))
241 : {
242 2954 : ulong hash = h->hash(k), index = hash % h->len;
243 2954 : hashentry **pE = &(h->table[index]), *e = *pE;
244 2954 : while (e)
245 : {
246 2954 : if (hash == e->hash && h->eq(k, e->key) && select(E,e)) {
247 2954 : *pE = e->next; h->nb--;
248 2954 : return e;
249 : }
250 0 : pE = &(e->next);
251 0 : e = e->next;
252 : }
253 0 : return NULL;
254 : }
255 :
256 : hashentry *
257 24 : hash_remove(hashtable *h, void *k)
258 : {
259 24 : ulong hash = h->hash(k), index = hash % h->len;
260 24 : hashentry **pE = &(h->table[index]), *e = *pE;
261 24 : while (e)
262 : {
263 24 : if (hash == e->hash && h->eq(k, e->key)) {
264 24 : *pE = e->next; h->nb--;
265 24 : return e;
266 : }
267 0 : pE = &(e->next);
268 0 : e = e->next;
269 : }
270 0 : return NULL;
271 : }
272 : void
273 3612 : hash_destroy(hashtable *h)
274 : {
275 : ulong i;
276 3612 : if (h->use_stack) return;
277 447888 : for (i = 0; i < h->len; i++)
278 : {
279 444276 : hashentry *e = h->table[i];
280 450218 : while (e) { hashentry *f = e; e = e->next; pari_free(f); }
281 : }
282 3612 : pari_free(h->table); pari_free(h);
283 : }
284 :
285 : static
286 15764 : int strequal(void *a, void *b) { return !strcmp((char*)a,(char*)b); }
287 : hashtable *
288 3657 : hash_create_str(ulong s, long stack)
289 3657 : { return hash_create(s, (ulong (*)(void *))&hash_str, strequal, stack); }
290 :
291 : hashtable *
292 25 : hashstr_import_static(hashentry *e, ulong size)
293 : {
294 25 : hashtable *h = hash_create_str(size, 0);
295 16500 : for ( ; e->key; e++) { hash_link(h, e); h->nb++; }
296 25 : return h;
297 : }
298 :
299 : void
300 0 : hash_dbg(hashtable *h)
301 : {
302 0 : ulong n, Total = 0, Max = 0;
303 0 : hashentry *e, **table = h->table;
304 0 : for (n=0; n < h->len; n++)
305 : {
306 0 : ulong m=0;
307 0 : for (e=table[n]; e; e=e->next) m++;
308 0 : Total += m; if (Max < m) Max = m;
309 0 : pari_printf("%4ld:%2ld ",n,m);
310 0 : if (n%9 == 8) pari_putc('\n');
311 : }
312 0 : pari_printf("\nTotal = %ld, Max = %ld\n", Total, Max);
313 0 : }
314 :
315 : /********************************************************************/
316 : /* */
317 : /* HASH FUNCTIONS */
318 : /* */
319 : /********************************************************************/
320 :
321 : INLINE ulong
322 551846980 : glue(ulong h, ulong a) { return 404936533*h + a; }
323 : ulong
324 134493874 : hash_GEN(GEN x)
325 : {
326 134493874 : ulong h = x[0] & ~CLONEBIT;
327 134493874 : long tx = typ(x), lx, i;
328 134493874 : switch(tx)
329 : { /* non recursive types */
330 49991415 : case t_INT:
331 49991415 : lx = lgefint(x);
332 49991415 : h &= TYPBITS;
333 154302933 : for (i = 1; i < lx; i++) h = glue(h, uel(x,i));
334 49991415 : return h;
335 67724838 : case t_REAL:
336 : case t_STR:
337 : case t_VECSMALL:
338 67724838 : lx = lg(x);
339 463627722 : for (i = 1; i < lx; i++) h = glue(h, uel(x,i));
340 67724838 : return h;
341 : /* one more special case */
342 0 : case t_LIST:
343 0 : x = list_data(x);
344 0 : if (!x) return h;
345 : /* fall through */
346 : default:
347 16777621 : if (lontyp[tx] == 2) { h = glue(h, x[1]); i = 2; } else i = 1;
348 16777621 : lx = lg(x);
349 67376545 : for (; i < lx; i++) h = glue(h, hash_GEN(gel(x,i)));
350 16777622 : return h;
351 : }
352 : }
353 : ulong
354 17507 : hash_zv(GEN x)
355 : {
356 17507 : long i, lx = lg(x);
357 : ulong h;
358 17507 : if (lx == 1) return 0;
359 15701 : h = x[1];
360 108514 : for (i = 1; i < lx; i++) h = glue(h, uel(x,i));
361 15701 : return h;
362 : }
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