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Commit | Line | Data |
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ccc6cda3 | 1 | /* hashlib.c -- functions to manage and access hash tables for bash. */ |
726f6388 | 2 | |
3185942a | 3 | /* Copyright (C) 1987,1989,1991,1995,1998,2001,2003,2005,2006,2008,2009 Free Software Foundation, Inc. |
726f6388 | 4 | |
3185942a | 5 | This file is part of GNU Bash, the Bourne Again SHell. |
726f6388 | 6 | |
3185942a JA |
7 | Bash is free software: you can redistribute it and/or modify |
8 | it under the terms of the GNU General Public License as published by | |
9 | the Free Software Foundation, either version 3 of the License, or | |
10 | (at your option) any later version. | |
726f6388 | 11 | |
3185942a JA |
12 | Bash is distributed in the hope that it will be useful, |
13 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | GNU General Public License for more details. | |
726f6388 | 16 | |
3185942a JA |
17 | You should have received a copy of the GNU General Public License |
18 | along with Bash. If not, see <http://www.gnu.org/licenses/>. | |
19 | */ | |
726f6388 | 20 | |
bb70624e | 21 | #include <config.h> |
726f6388 | 22 | |
d166f048 | 23 | #include "bashansi.h" |
726f6388 | 24 | |
ccc6cda3 | 25 | #if defined (HAVE_UNISTD_H) |
cce855bc JA |
26 | # ifdef _MINIX |
27 | # include <sys/types.h> | |
28 | # endif | |
ccc6cda3 JA |
29 | # include <unistd.h> |
30 | #endif | |
726f6388 | 31 | |
d166f048 JA |
32 | #include <stdio.h> |
33 | ||
ccc6cda3 JA |
34 | #include "shell.h" |
35 | #include "hashlib.h" | |
726f6388 | 36 | |
7117c2d2 JA |
37 | /* Rely on properties of unsigned division (unsigned/int -> unsigned) and |
38 | don't discard the upper 32 bits of the value, if present. */ | |
39 | #define HASH_BUCKET(s, t, h) (((h) = hash_string (s)) & ((t)->nbuckets - 1)) | |
f73dda09 | 40 | |
7117c2d2 | 41 | static BUCKET_CONTENTS *copy_bucket_array __P((BUCKET_CONTENTS *, sh_string_func_t *)); |
726f6388 JA |
42 | |
43 | /* Make a new hash table with BUCKETS number of buckets. Initialize | |
44 | each slot in the table to NULL. */ | |
45 | HASH_TABLE * | |
7117c2d2 | 46 | hash_create (buckets) |
726f6388 JA |
47 | int buckets; |
48 | { | |
ccc6cda3 | 49 | HASH_TABLE *new_table; |
7117c2d2 | 50 | register int i; |
726f6388 | 51 | |
ccc6cda3 | 52 | new_table = (HASH_TABLE *)xmalloc (sizeof (HASH_TABLE)); |
726f6388 JA |
53 | if (buckets == 0) |
54 | buckets = DEFAULT_HASH_BUCKETS; | |
55 | ||
56 | new_table->bucket_array = | |
57 | (BUCKET_CONTENTS **)xmalloc (buckets * sizeof (BUCKET_CONTENTS *)); | |
58 | new_table->nbuckets = buckets; | |
59 | new_table->nentries = 0; | |
7117c2d2 JA |
60 | |
61 | for (i = 0; i < buckets; i++) | |
62 | new_table->bucket_array[i] = (BUCKET_CONTENTS *)NULL; | |
63 | ||
726f6388 JA |
64 | return (new_table); |
65 | } | |
66 | ||
f73dda09 | 67 | int |
7117c2d2 | 68 | hash_size (table) |
f73dda09 JA |
69 | HASH_TABLE *table; |
70 | { | |
71 | return (HASH_ENTRIES(table)); | |
72 | } | |
73 | ||
74 | static BUCKET_CONTENTS * | |
75 | copy_bucket_array (ba, cpdata) | |
76 | BUCKET_CONTENTS *ba; | |
77 | sh_string_func_t *cpdata; /* data copy function */ | |
78 | { | |
79 | BUCKET_CONTENTS *new_bucket, *n, *e; | |
80 | ||
81 | if (ba == 0) | |
82 | return ((BUCKET_CONTENTS *)0); | |
83 | ||
84 | for (n = (BUCKET_CONTENTS *)0, e = ba; e; e = e->next) | |
85 | { | |
86 | if (n == 0) | |
87 | { | |
88 | new_bucket = (BUCKET_CONTENTS *)xmalloc (sizeof (BUCKET_CONTENTS)); | |
89 | n = new_bucket; | |
90 | } | |
91 | else | |
92 | { | |
93 | n->next = (BUCKET_CONTENTS *)xmalloc (sizeof (BUCKET_CONTENTS)); | |
94 | n = n->next; | |
95 | } | |
96 | ||
97 | n->key = savestring (e->key); | |
98 | n->data = e->data ? (cpdata ? (*cpdata) (e->data) : savestring (e->data)) | |
7117c2d2 JA |
99 | : NULL; |
100 | n->khash = e->khash; | |
f73dda09 JA |
101 | n->times_found = e->times_found; |
102 | n->next = (BUCKET_CONTENTS *)NULL; | |
103 | } | |
104 | ||
105 | return new_bucket; | |
106 | } | |
107 | ||
108 | HASH_TABLE * | |
7117c2d2 | 109 | hash_copy (table, cpdata) |
f73dda09 JA |
110 | HASH_TABLE *table; |
111 | sh_string_func_t *cpdata; | |
112 | { | |
113 | HASH_TABLE *new_table; | |
114 | int i; | |
115 | ||
116 | if (table == 0) | |
117 | return ((HASH_TABLE *)NULL); | |
118 | ||
7117c2d2 | 119 | new_table = hash_create (table->nbuckets); |
f73dda09 JA |
120 | |
121 | for (i = 0; i < table->nbuckets; i++) | |
122 | new_table->bucket_array[i] = copy_bucket_array (table->bucket_array[i], cpdata); | |
123 | ||
124 | new_table->nentries = table->nentries; | |
125 | return new_table; | |
126 | } | |
127 | ||
7117c2d2 JA |
128 | /* The `khash' check below requires that strings that compare equally with |
129 | strcmp hash to the same value. */ | |
130 | unsigned int | |
131 | hash_string (s) | |
132 | const char *s; | |
133 | { | |
134 | register unsigned int i; | |
726f6388 | 135 | |
7117c2d2 | 136 | /* This is the best string hash function I found. |
b72432fd | 137 | |
7117c2d2 JA |
138 | The magic is in the interesting relationship between the special prime |
139 | 16777619 (2^24 + 403) and 2^32 and 2^8. */ | |
140 | ||
141 | for (i = 0; *s; s++) | |
142 | { | |
143 | i *= 16777619; | |
144 | i ^= *s; | |
145 | } | |
146 | ||
147 | return i; | |
148 | } | |
149 | ||
150 | /* Return the location of the bucket which should contain the data | |
151 | for STRING. TABLE is a pointer to a HASH_TABLE. */ | |
726f6388 JA |
152 | |
153 | int | |
7117c2d2 | 154 | hash_bucket (string, table) |
f73dda09 | 155 | const char *string; |
726f6388 JA |
156 | HASH_TABLE *table; |
157 | { | |
7117c2d2 | 158 | unsigned int h; |
726f6388 | 159 | |
7117c2d2 | 160 | return (HASH_BUCKET (string, table, h)); |
726f6388 JA |
161 | } |
162 | ||
7117c2d2 JA |
163 | /* Return a pointer to the hashed item. If the HASH_CREATE flag is passed, |
164 | create a new hash table entry for STRING, otherwise return NULL. */ | |
726f6388 | 165 | BUCKET_CONTENTS * |
7117c2d2 | 166 | hash_search (string, table, flags) |
f73dda09 | 167 | const char *string; |
726f6388 | 168 | HASH_TABLE *table; |
7117c2d2 | 169 | int flags; |
726f6388 JA |
170 | { |
171 | BUCKET_CONTENTS *list; | |
7117c2d2 JA |
172 | int bucket; |
173 | unsigned int hv; | |
726f6388 | 174 | |
7117c2d2 | 175 | if (table == 0 || ((flags & HASH_CREATE) == 0 && HASH_ENTRIES (table) == 0)) |
726f6388 JA |
176 | return (BUCKET_CONTENTS *)NULL; |
177 | ||
7117c2d2 | 178 | bucket = HASH_BUCKET (string, table, hv); |
726f6388 | 179 | |
0001803f | 180 | for (list = table->bucket_array ? table->bucket_array[bucket] : 0; list; list = list->next) |
726f6388 | 181 | { |
7117c2d2 | 182 | if (hv == list->khash && STREQ (list->key, string)) |
726f6388 JA |
183 | { |
184 | list->times_found++; | |
185 | return (list); | |
186 | } | |
726f6388 | 187 | } |
7117c2d2 JA |
188 | |
189 | if (flags & HASH_CREATE) | |
190 | { | |
191 | list = (BUCKET_CONTENTS *)xmalloc (sizeof (BUCKET_CONTENTS)); | |
192 | list->next = table->bucket_array[bucket]; | |
193 | table->bucket_array[bucket] = list; | |
194 | ||
195 | list->data = NULL; | |
196 | list->key = (char *)string; /* XXX fix later */ | |
197 | list->khash = hv; | |
198 | list->times_found = 0; | |
199 | ||
200 | table->nentries++; | |
201 | return (list); | |
202 | } | |
203 | ||
726f6388 JA |
204 | return (BUCKET_CONTENTS *)NULL; |
205 | } | |
206 | ||
207 | /* Remove the item specified by STRING from the hash table TABLE. | |
208 | The item removed is returned, so you can free its contents. If | |
209 | the item isn't in this table NULL is returned. */ | |
210 | BUCKET_CONTENTS * | |
7117c2d2 | 211 | hash_remove (string, table, flags) |
f73dda09 | 212 | const char *string; |
726f6388 | 213 | HASH_TABLE *table; |
7117c2d2 | 214 | int flags; |
726f6388 | 215 | { |
7117c2d2 | 216 | int bucket; |
726f6388 | 217 | BUCKET_CONTENTS *prev, *temp; |
7117c2d2 | 218 | unsigned int hv; |
726f6388 | 219 | |
7117c2d2 | 220 | if (table == 0 || HASH_ENTRIES (table) == 0) |
726f6388 JA |
221 | return (BUCKET_CONTENTS *)NULL; |
222 | ||
7117c2d2 | 223 | bucket = HASH_BUCKET (string, table, hv); |
726f6388 | 224 | prev = (BUCKET_CONTENTS *)NULL; |
7117c2d2 | 225 | for (temp = table->bucket_array[bucket]; temp; temp = temp->next) |
726f6388 | 226 | { |
7117c2d2 | 227 | if (hv == temp->khash && STREQ (temp->key, string)) |
726f6388 JA |
228 | { |
229 | if (prev) | |
230 | prev->next = temp->next; | |
231 | else | |
7117c2d2 | 232 | table->bucket_array[bucket] = temp->next; |
726f6388 JA |
233 | |
234 | table->nentries--; | |
235 | return (temp); | |
236 | } | |
237 | prev = temp; | |
726f6388 JA |
238 | } |
239 | return ((BUCKET_CONTENTS *) NULL); | |
240 | } | |
241 | ||
242 | /* Create an entry for STRING, in TABLE. If the entry already | |
7117c2d2 | 243 | exists, then return it (unless the HASH_NOSRCH flag is set). */ |
726f6388 | 244 | BUCKET_CONTENTS * |
7117c2d2 | 245 | hash_insert (string, table, flags) |
726f6388 JA |
246 | char *string; |
247 | HASH_TABLE *table; | |
7117c2d2 | 248 | int flags; |
726f6388 JA |
249 | { |
250 | BUCKET_CONTENTS *item; | |
ccc6cda3 | 251 | int bucket; |
7117c2d2 | 252 | unsigned int hv; |
726f6388 | 253 | |
ccc6cda3 | 254 | if (table == 0) |
7117c2d2 | 255 | table = hash_create (0); |
726f6388 | 256 | |
7117c2d2 JA |
257 | item = (flags & HASH_NOSRCH) ? (BUCKET_CONTENTS *)NULL |
258 | : hash_search (string, table, 0); | |
259 | ||
260 | if (item == 0) | |
726f6388 | 261 | { |
7117c2d2 | 262 | bucket = HASH_BUCKET (string, table, hv); |
726f6388 | 263 | |
7117c2d2 JA |
264 | item = (BUCKET_CONTENTS *)xmalloc (sizeof (BUCKET_CONTENTS)); |
265 | item->next = table->bucket_array[bucket]; | |
266 | table->bucket_array[bucket] = item; | |
726f6388 | 267 | |
7117c2d2 | 268 | item->data = NULL; |
726f6388 | 269 | item->key = string; |
7117c2d2 | 270 | item->khash = hv; |
726f6388 | 271 | item->times_found = 0; |
7117c2d2 JA |
272 | |
273 | table->nentries++; | |
726f6388 JA |
274 | } |
275 | ||
276 | return (item); | |
277 | } | |
278 | ||
ccc6cda3 JA |
279 | /* Remove and discard all entries in TABLE. If FREE_DATA is non-null, it |
280 | is a function to call to dispose of a hash item's data. Otherwise, | |
281 | free() is called. */ | |
282 | void | |
7117c2d2 | 283 | hash_flush (table, free_data) |
ccc6cda3 | 284 | HASH_TABLE *table; |
f73dda09 | 285 | sh_free_func_t *free_data; |
ccc6cda3 JA |
286 | { |
287 | int i; | |
288 | register BUCKET_CONTENTS *bucket, *item; | |
289 | ||
7117c2d2 | 290 | if (table == 0 || HASH_ENTRIES (table) == 0) |
d166f048 JA |
291 | return; |
292 | ||
ccc6cda3 JA |
293 | for (i = 0; i < table->nbuckets; i++) |
294 | { | |
295 | bucket = table->bucket_array[i]; | |
296 | ||
297 | while (bucket) | |
298 | { | |
299 | item = bucket; | |
300 | bucket = bucket->next; | |
301 | ||
302 | if (free_data) | |
303 | (*free_data) (item->data); | |
304 | else | |
305 | free (item->data); | |
306 | free (item->key); | |
307 | free (item); | |
308 | } | |
309 | table->bucket_array[i] = (BUCKET_CONTENTS *)NULL; | |
310 | } | |
7117c2d2 JA |
311 | |
312 | table->nentries = 0; | |
ccc6cda3 JA |
313 | } |
314 | ||
d166f048 JA |
315 | /* Free the hash table pointed to by TABLE. */ |
316 | void | |
7117c2d2 | 317 | hash_dispose (table) |
d166f048 JA |
318 | HASH_TABLE *table; |
319 | { | |
320 | free (table->bucket_array); | |
321 | free (table); | |
322 | } | |
323 | ||
7117c2d2 JA |
324 | void |
325 | hash_walk (table, func) | |
726f6388 | 326 | HASH_TABLE *table; |
7117c2d2 | 327 | hash_wfunc *func; |
726f6388 | 328 | { |
7117c2d2 JA |
329 | register int i; |
330 | BUCKET_CONTENTS *item; | |
331 | ||
332 | if (table == 0 || HASH_ENTRIES (table) == 0) | |
333 | return; | |
334 | ||
335 | for (i = 0; i < table->nbuckets; i++) | |
336 | { | |
337 | for (item = hash_items (i, table); item; item = item->next) | |
338 | if ((*func) (item) < 0) | |
339 | return; | |
340 | } | |
726f6388 JA |
341 | } |
342 | ||
7117c2d2 | 343 | #if defined (DEBUG) || defined (TEST_HASHING) |
cce855bc | 344 | void |
7117c2d2 | 345 | hash_pstats (table, name) |
d166f048 JA |
346 | HASH_TABLE *table; |
347 | char *name; | |
348 | { | |
349 | register int slot, bcount; | |
350 | register BUCKET_CONTENTS *bc; | |
351 | ||
352 | if (name == 0) | |
353 | name = "unknown hash table"; | |
354 | ||
355 | fprintf (stderr, "%s: %d buckets; %d items\n", name, table->nbuckets, table->nentries); | |
356 | ||
357 | /* Print out a count of how many strings hashed to each bucket, so we can | |
358 | see how even the distribution is. */ | |
359 | for (slot = 0; slot < table->nbuckets; slot++) | |
360 | { | |
7117c2d2 | 361 | bc = hash_items (slot, table); |
d166f048 JA |
362 | |
363 | fprintf (stderr, "\tslot %3d: ", slot); | |
364 | for (bcount = 0; bc; bc = bc->next) | |
28ef6c31 | 365 | bcount++; |
d166f048 JA |
366 | |
367 | fprintf (stderr, "%d\n", bcount); | |
368 | } | |
369 | } | |
cce855bc | 370 | #endif |
d166f048 | 371 | |
726f6388 JA |
372 | #ifdef TEST_HASHING |
373 | ||
7117c2d2 | 374 | /* link with xmalloc.o and lib/malloc/libmalloc.a */ |
726f6388 JA |
375 | #undef NULL |
376 | #include <stdio.h> | |
377 | ||
f73dda09 JA |
378 | #ifndef NULL |
379 | #define NULL 0 | |
380 | #endif | |
381 | ||
382 | HASH_TABLE *table, *ntable; | |
726f6388 | 383 | |
7117c2d2 JA |
384 | int interrupt_immediately = 0; |
385 | ||
386 | int | |
387 | signal_is_trapped (s) | |
388 | int s; | |
726f6388 | 389 | { |
7117c2d2 JA |
390 | return (0); |
391 | } | |
392 | ||
393 | void | |
394 | programming_error (const char *format, ...) | |
395 | { | |
396 | abort(); | |
397 | } | |
398 | ||
399 | void | |
400 | fatal_error (const char *format, ...) | |
401 | { | |
402 | abort(); | |
726f6388 JA |
403 | } |
404 | ||
405 | main () | |
406 | { | |
407 | char string[256]; | |
408 | int count = 0; | |
409 | BUCKET_CONTENTS *tt; | |
410 | ||
7117c2d2 | 411 | table = hash_create (0); |
ccc6cda3 | 412 | |
726f6388 JA |
413 | for (;;) |
414 | { | |
415 | char *temp_string; | |
416 | if (fgets (string, sizeof (string), stdin) == 0) | |
28ef6c31 | 417 | break; |
726f6388 | 418 | if (!*string) |
28ef6c31 | 419 | break; |
726f6388 | 420 | temp_string = savestring (string); |
7117c2d2 | 421 | tt = hash_insert (temp_string, table, 0); |
726f6388 JA |
422 | if (tt->times_found) |
423 | { | |
424 | fprintf (stderr, "You have already added item `%s'\n", string); | |
425 | free (temp_string); | |
426 | } | |
427 | else | |
428 | { | |
429 | count++; | |
430 | } | |
431 | } | |
ccc6cda3 | 432 | |
7117c2d2 | 433 | hash_pstats (table, "hash test"); |
f73dda09 | 434 | |
7117c2d2 JA |
435 | ntable = hash_copy (table, (sh_string_func_t *)NULL); |
436 | hash_flush (table, (sh_free_func_t *)NULL); | |
437 | hash_pstats (ntable, "hash copy test"); | |
f73dda09 | 438 | |
d166f048 | 439 | exit (0); |
726f6388 JA |
440 | } |
441 | ||
442 | #endif /* TEST_HASHING */ |