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28bf4b0b | 1 | /* |
2 | ** LCLint - annotation-assisted static program checker | |
3 | ** Copyright (C) 1994-2001 University of Virginia, | |
4 | ** Massachusetts Institute of Technology | |
5 | ** | |
6 | ** This program is free software; you can redistribute it and/or modify it | |
7 | ** under the terms of the GNU General Public License as published by the | |
8 | ** Free Software Foundation; either version 2 of the License, or (at your | |
9 | ** option) any later version. | |
10 | ** | |
11 | ** This program is distributed in the hope that it will be useful, but | |
12 | ** WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | ** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
14 | ** General Public License for more details. | |
15 | ** | |
16 | ** The GNU General Public License is available from http://www.gnu.org/ or | |
17 | ** the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, | |
18 | ** MA 02111-1307, USA. | |
19 | ** | |
20 | ** For information on lclint: lclint-request@cs.virginia.edu | |
21 | ** To report a bug: lclint-bug@cs.virginia.edu | |
22 | ** For more information: http://lclint.cs.virginia.edu | |
23 | */ | |
24 | /* | |
25 | ** genericTable.c | |
26 | ** | |
27 | ** A genericTable is a mapping from string keys to void * objects. | |
28 | ** We sacrific type checking here for code reuse. | |
29 | */ | |
30 | ||
31 | # include "lclintMacros.nf" | |
32 | # include "basic.h" | |
33 | # include "randomNumbers.h" | |
34 | ||
35 | /*@constant null ghbucket ghbucket_undefined; @*/ | |
36 | # define ghbucket_undefined 0 | |
37 | ||
38 | static /*@truenull@*/ bool ghbucket_isNull (/*@null@*/ ghbucket h) | |
39 | { | |
40 | return (h == ghbucket_undefined); | |
41 | } | |
42 | ||
43 | static ghentry | |
44 | ghentry_create (/*@keep@*/ cstring key, /*@keep@*/ void *val) | |
45 | { | |
46 | ghentry h = (ghentry) dmalloc (sizeof (*h)); | |
47 | ||
48 | h->key = key; | |
49 | ||
50 | llassert (val != NULL); | |
51 | h->val = val; | |
52 | ||
53 | return (h); | |
54 | } | |
55 | ||
56 | static bool | |
57 | ghbucket_isEmpty (ghbucket h) | |
58 | { | |
59 | return (h == ghbucket_undefined || h->size == 0); | |
60 | } | |
61 | ||
62 | int genericTable_size (genericTable h) | |
63 | { | |
64 | if (genericTable_isDefined (h)) { | |
65 | return h->nentries; | |
66 | } else { | |
67 | return 0; | |
68 | } | |
69 | } | |
70 | ||
71 | static cstring | |
72 | ghbucket_unparse (ghbucket h) | |
73 | { | |
74 | cstring s = cstring_undefined; | |
75 | ||
76 | if (!ghbucket_isNull (h)) | |
77 | { | |
78 | int i; | |
79 | ||
80 | for (i = 0; i < h->size; i++) | |
81 | { | |
82 | s = message ("%q %s", s, h->entries[i]->key); | |
83 | } | |
84 | } | |
85 | ||
86 | return s; | |
87 | } | |
88 | ||
89 | static ghbucket ghbucket_single (/*@keep@*/ ghentry e) | |
90 | { | |
91 | ghbucket h = (ghbucket) dmalloc (sizeof (*h)); | |
92 | ||
93 | h->size = 1; | |
94 | h->nspace = GHBUCKET_BASESIZE - 1; | |
95 | h->entries = (ghentry *) dmalloc (GHBUCKET_BASESIZE * sizeof (*h->entries)); | |
96 | /*@i23@*/ h->entries[0] = e; | |
97 | ||
98 | return (h); | |
99 | } | |
100 | ||
101 | static void | |
102 | ghbucket_grow (/*@notnull@*/ ghbucket h) | |
103 | { | |
104 | int i; | |
105 | ghentry *newentries; | |
106 | ||
107 | h->nspace += GHBUCKET_BASESIZE; | |
108 | ||
109 | newentries = (ghentry *) | |
110 | dmalloc ((h->size + GHBUCKET_BASESIZE) * sizeof (*newentries)); | |
111 | ||
112 | for (i = 0; i < h->size; i++) | |
113 | { | |
114 | newentries[i] = h->entries[i]; | |
115 | } | |
116 | ||
117 | /*@i32@*/ sfree (h->entries); | |
118 | h->entries = newentries; | |
119 | /*@i32@*/ } | |
120 | ||
121 | static /*@null@*/ /*@exposed@*/ void *ghbucket_lookup (ghbucket p_h, cstring p_key); | |
122 | ||
123 | /* | |
124 | ** bizarre duplicate behaviour | |
125 | ** required for duplicate entries | |
126 | */ | |
127 | ||
128 | static void | |
129 | ghbucket_add (/*@notnull@*/ ghbucket h, /*@only@*/ ghentry e) | |
130 | { | |
131 | void *exloc = ghbucket_lookup (h, e->key); | |
132 | ||
133 | if (exloc != NULL) { | |
134 | llassert (FALSE); | |
135 | } | |
136 | ||
137 | if (h->nspace == 0) { | |
138 | ghbucket_grow (h); | |
139 | } | |
140 | ||
141 | h->entries[h->size] = e; | |
142 | h->size++; | |
143 | h->nspace--; | |
144 | /*@i23@*/ } | |
145 | ||
146 | static int | |
147 | ghbucket_ncollisions (ghbucket h) | |
148 | { | |
149 | if (!ghbucket_isNull (h) && (h->size > 1)) | |
150 | return (h->size - 1); | |
151 | else | |
152 | return 0; | |
153 | } | |
154 | ||
155 | /*@exposed@*/ /*@null@*/ void * | |
156 | ghbucket_lookup (ghbucket h, cstring key) | |
157 | { | |
158 | if (!ghbucket_isNull (h)) | |
159 | { | |
160 | int i; | |
161 | ||
162 | for (i = 0; i < h->size; i++) | |
163 | { | |
164 | if (cstring_equal (h->entries[i]->key, key)) | |
165 | { | |
166 | return h->entries[i]->val; | |
167 | } | |
168 | } | |
169 | } | |
170 | ||
171 | return NULL; | |
172 | } | |
173 | ||
174 | static | |
175 | void ghbucket_free (/*@only@*/ ghbucket h) | |
176 | { | |
177 | if (!ghbucket_isNull (h)) | |
178 | { | |
179 | /*@i32@*/ sfree (h->entries); | |
180 | sfree (h); | |
181 | } | |
182 | } | |
183 | ||
184 | void | |
185 | genericTable_free (/*@only@*/ genericTable h) | |
186 | { | |
187 | if (genericTable_isDefined (h)) | |
188 | { | |
189 | int i; | |
190 | ||
191 | for (i = 0; i < h->size; i++) | |
192 | { | |
193 | ghbucket_free (h->buckets[i]); | |
194 | } | |
195 | ||
196 | sfree (h->buckets); | |
197 | sfree (h); | |
198 | } | |
199 | } | |
200 | ||
201 | static int | |
202 | genericTable_countCollisions (genericTable h) | |
203 | { | |
204 | int nc = 0; | |
205 | int i; | |
206 | ||
207 | llassert (genericTable_isDefined (h)); | |
208 | ||
209 | for (i = 0; i < h->size; i++) | |
210 | { | |
211 | nc += ghbucket_ncollisions (h->buckets[i]); | |
212 | } | |
213 | ||
214 | return (nc); | |
215 | } | |
216 | ||
217 | ||
218 | static int | |
219 | genericTable_countEmpty (genericTable h) | |
220 | { | |
221 | int nc = 0; | |
222 | int i; | |
223 | ||
224 | llassert (genericTable_isDefined (h)); | |
225 | ||
226 | for (i = 0; i < h->size; i++) | |
227 | { | |
228 | if (ghbucket_isEmpty (h->buckets[i])) | |
229 | { | |
230 | nc++; | |
231 | } | |
232 | } | |
233 | ||
234 | return (nc); | |
235 | } | |
236 | ||
237 | /* | |
238 | ** hash function snarfed from quake/hash.c Hash_String | |
239 | ** by Stephen Harrison | |
240 | */ | |
241 | ||
242 | static unsigned int | |
243 | genericTable_hashValue (/*@notnull@*/ genericTable h, cstring key) | |
244 | { | |
245 | char *p; | |
246 | unsigned int hash_value = 0; | |
247 | ||
248 | llassert (h->size != 0); | |
249 | ||
250 | for (p = cstring_toCharsSafe (key); *p != '\0'; p++) | |
251 | { | |
252 | hash_value = (hash_value << 1) ^ g_randomNumbers[*p % 256]; | |
253 | } | |
254 | ||
255 | return (hash_value % h->size); | |
256 | } | |
257 | ||
258 | static /*@exposed@*/ ghbucket | |
259 | genericTable_hash (/*@notnull@*/ genericTable h, cstring key) | |
260 | { | |
261 | return h->buckets[genericTable_hashValue (h, key)]; | |
262 | } | |
263 | ||
264 | ||
265 | /*@only@*/ genericTable | |
266 | genericTable_create (int size) | |
267 | { | |
268 | int i; | |
269 | genericTable h = (genericTable) dmalloc (sizeof (*h)); | |
270 | ||
271 | llassert (size > 0); | |
272 | h->size = size; | |
273 | h->nentries = 0; | |
274 | h->buckets = (ghbucket *) dmalloc (sizeof (*h->buckets) * size); | |
275 | ||
276 | /*@+loopexec@*/ | |
277 | for (i = 0; i < size; i++) | |
278 | { | |
279 | h->buckets[i] = ghbucket_undefined; | |
280 | } | |
281 | /*@-loopexec@*/ | |
282 | return h; | |
283 | } | |
284 | ||
285 | /*@-mustfree@*/ | |
286 | static /*@unused@*/ void | |
287 | genericTable_print (genericTable h) | |
288 | { | |
289 | int i; | |
290 | ||
291 | if (genericTable_isDefined (h)) { | |
292 | for (i = 0; i < h->size; i++) | |
293 | { | |
294 | ghbucket hb = h->buckets[i]; | |
295 | ||
296 | if (hb != NULL) | |
297 | { | |
298 | llmsg (message ("%d. %s\n", i, ghbucket_unparse (hb))); | |
299 | } | |
300 | } | |
301 | ||
302 | llmsg (message ("size: %d, collisions: %d, empty: %d", | |
303 | h->size, | |
304 | genericTable_countCollisions (h), | |
305 | genericTable_countEmpty (h))); | |
306 | } else { | |
307 | llmsglit ("Empty hash table."); | |
308 | } | |
309 | } | |
310 | /*@=mustfree@*/ | |
311 | ||
312 | /*@only@*/ cstring | |
313 | genericTable_stats (genericTable h) | |
314 | { | |
315 | llassert (genericTable_isDefined (h)); | |
316 | return (message ("size: %d, collisions: %d, empty: %d\n", | |
317 | h->size, genericTable_countCollisions (h), | |
318 | genericTable_countEmpty (h))); | |
319 | } | |
320 | ||
321 | static void | |
322 | genericTable_addEntry (/*@notnull@*/ genericTable h, /*@keep@*/ ghentry e) | |
323 | { | |
324 | unsigned int hindex = genericTable_hashValue (h, e->key); | |
325 | /* | |
326 | ** using | |
327 | ** ghbucket hb = h->buckets[hindex]; | |
328 | ** instead reveals a bug I don't want to deal with right now! | |
329 | */ | |
330 | ||
331 | h->nentries++; | |
332 | ||
333 | if (ghbucket_isNull (h->buckets[hindex])) | |
334 | { | |
335 | h->buckets[hindex] = ghbucket_single (e); | |
336 | } | |
337 | else | |
338 | { | |
339 | /*@i23@*/ ghbucket_add (h->buckets[hindex], e); | |
340 | /*@i23@*/ } | |
341 | } | |
342 | ||
343 | void | |
344 | genericTable_insert (genericTable h, cstring key, void *value) | |
345 | { | |
346 | unsigned int hindex; | |
347 | ghbucket hb; | |
348 | ghentry e; | |
349 | ||
350 | llassert (genericTable_isDefined (h)); | |
351 | ||
352 | /* | |
353 | ** rehashing based (loosely) on code by Steve Harrison | |
354 | */ | |
355 | ||
356 | if (h->nentries * 162 > h->size * 100) | |
357 | { | |
358 | int i; | |
359 | int oldsize = h->size; | |
360 | int newsize = 1 + ((oldsize * 26244) / 10000); /* 26244 = 162^2 */ | |
361 | ghbucket *oldbuckets = h->buckets; | |
362 | ||
363 | DPRINTF (("Rehashing...")); | |
364 | h->size = newsize; | |
365 | h->nentries = 0; | |
366 | h->buckets = (ghbucket *) dmalloc (sizeof (*h->buckets) * newsize); | |
367 | ||
368 | /*@+loopexec@*/ | |
369 | for (i = 0; i < newsize; i++) | |
370 | { | |
371 | h->buckets[i] = ghbucket_undefined; | |
372 | } | |
373 | /*@=loopexec@*/ | |
374 | ||
375 | for (i = 0; i < oldsize; i++) | |
376 | { | |
377 | ghbucket bucket = oldbuckets[i]; | |
378 | ||
379 | oldbuckets[i] = NULL; | |
380 | ||
381 | if (!ghbucket_isNull (bucket)) | |
382 | { | |
383 | int j; | |
384 | ||
385 | for (j = 0; j < bucket->size; j++) | |
386 | { | |
387 | genericTable_addEntry (h, bucket->entries[j]); | |
388 | } | |
389 | ||
390 | sfree (bucket->entries); /* evans 2001-03-24: LCLint caught this */ | |
391 | sfree (bucket); | |
392 | } | |
393 | } | |
394 | ||
395 | sfree (oldbuckets); | |
396 | } | |
397 | ||
398 | /* evans 2000-12-22: this was before the rehash! Lost an entry size! */ | |
399 | h->nentries++; | |
400 | e = ghentry_create (key, value); | |
401 | hindex = genericTable_hashValue (h, key); | |
402 | hb = h->buckets[hindex]; | |
403 | ||
404 | if (ghbucket_isNull (hb)) | |
405 | { | |
406 | /*@i23@*/ h->buckets[hindex] = ghbucket_single (e); | |
407 | } | |
408 | else | |
409 | { | |
410 | ghbucket_add (hb, e); | |
411 | /*@i23@*/ } | |
412 | /*@i23@*/ } | |
413 | ||
414 | /*@null@*/ /*@exposed@*/ void * | |
415 | genericTable_lookup (genericTable h, cstring key) | |
416 | { | |
417 | ghbucket hb; | |
418 | void *res; | |
419 | llassert (genericTable_isDefined (h)); | |
420 | ||
421 | hb = genericTable_hash (h, key); | |
422 | res = ghbucket_lookup (hb, key); | |
423 | ||
424 | /* if (res == NULL) { DPRINTF (("Lookup not found: %s", key)); } */ | |
425 | return res; | |
426 | } | |
427 | ||
428 | void | |
429 | genericTable_update (genericTable h, cstring key, /*@only@*/ void *newval) | |
430 | { | |
431 | ghbucket hb; | |
432 | ||
433 | llassert (genericTable_isDefined (h)); | |
434 | ||
435 | hb = genericTable_hash (h, key); | |
436 | ||
437 | if (!ghbucket_isNull (hb)) | |
438 | { | |
439 | int i; | |
440 | ||
441 | for (i = 0; i < hb->size; i++) | |
442 | { | |
443 | if (cstring_equal (hb->entries[i]->key, key)) | |
444 | { | |
445 | llassert (newval != NULL); | |
446 | hb->entries[i]->val = newval; | |
447 | return; | |
448 | } | |
449 | } | |
450 | } | |
451 | ||
452 | llbug (message ("genericTable_update: %s not found", key)); | |
453 | } | |
454 | ||
455 | void | |
456 | genericTable_remove (genericTable h, cstring key) | |
457 | { | |
458 | ghbucket hb; | |
459 | ||
460 | llassert (genericTable_isDefined (h)); | |
461 | hb = genericTable_hash (h, key); | |
462 | ||
463 | if (!ghbucket_isNull (hb)) | |
464 | { | |
465 | int i; | |
466 | ||
467 | for (i = 0; i < hb->size; i++) | |
468 | { | |
469 | if (cstring_equal (hb->entries[i]->key, key)) | |
470 | { | |
471 | if (i < hb->size - 1) | |
472 | { | |
473 | hb->entries[i] = hb->entries[hb->size - 1]; | |
474 | } | |
475 | ||
476 | hb->size--; | |
477 | return; | |
478 | } | |
479 | } | |
480 | } | |
481 | ||
482 | llbug (message ("genericTable_removeKey: %s not found", key)); | |
483 | } | |
484 | ||
485 | bool genericTable_contains (genericTable h, cstring key) | |
486 | { | |
487 | return (genericTable_lookup (h, key) != NULL); | |
488 | } |