1 /* Copyright (C) 2000-2010 Red Hat, Inc.
2 This file is part of Red Hat elfutils.
3 Written by Ulrich Drepper <drepper@redhat.com>, 2000.
4
5 Red Hat elfutils is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by the
7 Free Software Foundation; version 2 of the License.
8
9 Red Hat elfutils is distributed in the hope that it will be useful, but
10 WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 General Public License for more details.
13
14 You should have received a copy of the GNU General Public License along
15 with Red Hat elfutils; if not, write to the Free Software Foundation,
16 Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301 USA.
17
18 In addition, as a special exception, Red Hat, Inc. gives You the
19 additional right to link the code of Red Hat elfutils with code licensed
20 under any Open Source Initiative certified open source license
21 (http://www.opensource.org/licenses/index.php) which requires the
22 distribution of source code with any binary distribution and to
23 distribute linked combinations of the two. Non-GPL Code permitted under
24 this exception must only link to the code of Red Hat elfutils through
25 those well defined interfaces identified in the file named EXCEPTION
26 found in the source code files (the "Approved Interfaces"). The files
27 of Non-GPL Code may instantiate templates or use macros or inline
28 functions from the Approved Interfaces without causing the resulting
29 work to be covered by the GNU General Public License. Only Red Hat,
30 Inc. may make changes or additions to the list of Approved Interfaces.
31 Red Hat's grant of this exception is conditioned upon your not adding
32 any new exceptions. If you wish to add a new Approved Interface or
33 exception, please contact Red Hat. You must obey the GNU General Public
34 License in all respects for all of the Red Hat elfutils code and other
35 code used in conjunction with Red Hat elfutils except the Non-GPL Code
36 covered by this exception. If you modify this file, you may extend this
37 exception to your version of the file, but you are not obligated to do
38 so. If you do not wish to provide this exception without modification,
39 you must delete this exception statement from your version and license
40 this file solely under the GPL without exception.
41
42 Red Hat elfutils is an included package of the Open Invention Network.
43 An included package of the Open Invention Network is a package for which
44 Open Invention Network licensees cross-license their patents. No patent
45 license is granted, either expressly or impliedly, by designation as an
46 included package. Should you wish to participate in the Open Invention
47 Network licensing program, please visit www.openinventionnetwork.com
48 <http://www.openinventionnetwork.com>. */
49
50 #include <assert.h>
51 #include <stdlib.h>
52 #include <system.h>
53
54 /* Before including this file the following macros must be defined:
55
56 NAME name of the hash table structure.
57 TYPE data type of the hash table entries
58 COMPARE comparison function taking two pointers to TYPE objects
59
60 The following macros if present select features:
61
62 ITERATE iterating over the table entries is possible
63 REVERSE iterate in reverse order of insert
64 */
65
66
67 static size_t
lookup(htab,hval,val)68 lookup (htab, hval, val)
69 NAME *htab;
70 HASHTYPE hval;
71 TYPE val __attribute__ ((unused));
72 {
73 /* First hash function: simply take the modul but prevent zero. */
74 size_t idx = 1 + hval % htab->size;
75
76 if (htab->table[idx].hashval != 0)
77 {
78 HASHTYPE hash;
79
80 if (htab->table[idx].hashval == hval
81 && COMPARE (htab->table[idx].data, val) == 0)
82 return idx;
83
84 /* Second hash function as suggested in [Knuth]. */
85 hash = 1 + hval % (htab->size - 2);
86
87 do
88 {
89 if (idx <= hash)
90 idx = htab->size + idx - hash;
91 else
92 idx -= hash;
93
94 /* If entry is found use it. */
95 if (htab->table[idx].hashval == hval
96 && COMPARE (htab->table[idx].data, val) == 0)
97 return idx;
98 }
99 while (htab->table[idx].hashval);
100 }
101 return idx;
102 }
103
104
105 static void
insert_entry_2(NAME * htab,HASHTYPE hval,size_t idx,TYPE data)106 insert_entry_2 (NAME *htab, HASHTYPE hval, size_t idx, TYPE data)
107 {
108 #ifdef ITERATE
109 if (htab->table[idx].hashval == 0)
110 {
111 # ifdef REVERSE
112 htab->table[idx].next = htab->first;
113 htab->first = &htab->table[idx];
114 # else
115 /* Add the new value to the list. */
116 if (htab->first == NULL)
117 htab->first = htab->table[idx].next = &htab->table[idx];
118 else
119 {
120 htab->table[idx].next = htab->first->next;
121 htab->first = htab->first->next = &htab->table[idx];
122 }
123 # endif
124 }
125 #endif
126
127 htab->table[idx].hashval = hval;
128 htab->table[idx].data = data;
129
130 ++htab->filled;
131 if (100 * htab->filled > 90 * htab->size)
132 {
133 /* Table is filled more than 90%. Resize the table. */
134 #ifdef ITERATE
135 __typeof__ (htab->first) first;
136 # ifndef REVERSE
137 __typeof__ (htab->first) runp;
138 # endif
139 #else
140 size_t old_size = htab->size;
141 #endif
142 #define _TABLE(name) \
143 name##_ent *table = htab->table
144 #define TABLE(name) _TABLE (name)
145 TABLE(NAME);
146
147 htab->size = next_prime (htab->size * 2);
148 htab->filled = 0;
149 #ifdef ITERATE
150 first = htab->first;
151 htab->first = NULL;
152 #endif
153 htab->table = calloc ((1 + htab->size), sizeof (htab->table[0]));
154 if (htab->table == NULL)
155 {
156 /* We cannot enlarge the table. Live with what we got. This
157 might lead to an infinite loop at some point, though. */
158 htab->table = table;
159 return;
160 }
161
162 /* Add the old entries to the new table. When iteration is
163 supported we maintain the order. */
164 #ifdef ITERATE
165 # ifdef REVERSE
166 while (first != NULL)
167 {
168 insert_entry_2 (htab, first->hashval,
169 lookup (htab, first->hashval, first->data),
170 first->data);
171
172 first = first->next;
173 }
174 # else
175 assert (first != NULL);
176 runp = first = first->next;
177 do
178 insert_entry_2 (htab, runp->hashval,
179 lookup (htab, runp->hashval, runp->data), runp->data);
180 while ((runp = runp->next) != first);
181 # endif
182 #else
183 for (idx = 1; idx <= old_size; ++idx)
184 if (table[idx].hashval != 0)
185 insert_entry_2 (htab, table[idx].hashval,
186 lookup (htab, table[idx].hashval, table[idx].data),
187 table[idx].data);
188 #endif
189
190 free (table);
191 }
192 }
193
194
195 int
196 #define INIT(name) _INIT (name)
197 #define _INIT(name) \
198 name##_init
199 INIT(NAME) (htab, init_size)
200 NAME *htab;
201 size_t init_size;
202 {
203 /* We need the size to be a prime. */
204 init_size = next_prime (init_size);
205
206 /* Initialize the data structure. */
207 htab->size = init_size;
208 htab->filled = 0;
209 #ifdef ITERATE
210 htab->first = NULL;
211 #endif
212 htab->table = (void *) calloc ((init_size + 1), sizeof (htab->table[0]));
213 if (htab->table == NULL)
214 return -1;
215
216 return 0;
217 }
218
219
220 int
221 #define FREE(name) _FREE (name)
222 #define _FREE(name) \
223 name##_free
224 FREE(NAME) (htab)
225 NAME *htab;
226 {
227 free (htab->table);
228 return 0;
229 }
230
231
232 int
233 #define INSERT(name) _INSERT (name)
234 #define _INSERT(name) \
235 name##_insert
236 INSERT(NAME) (htab, hval, data)
237 NAME *htab;
238 HASHTYPE hval;
239 TYPE data;
240 {
241 size_t idx;
242
243 /* Make the hash value nonzero. */
244 hval = hval ?: 1;
245
246 idx = lookup (htab, hval, data);
247
248 if (htab->table[idx].hashval != 0)
249 /* We don't want to overwrite the old value. */
250 return -1;
251
252 /* An empty bucket has been found. */
253 insert_entry_2 (htab, hval, idx, data);
254 return 0;
255 }
256
257
258 #ifdef OVERWRITE
259 int
260 #define INSERT(name) _INSERT (name)
261 #define _INSERT(name) \
262 name##_overwrite
263 INSERT(NAME) (htab, hval, data)
264 NAME *htab;
265 HASHTYPE hval;
266 TYPE data;
267 {
268 size_t idx;
269
270 /* Make the hash value nonzero. */
271 hval = hval ?: 1;
272
273 idx = lookup (htab, hval, data);
274
275 /* The correct bucket has been found. */
276 insert_entry_2 (htab, hval, idx, data);
277 return 0;
278 }
279 #endif
280
281
282 TYPE
283 #define FIND(name) _FIND (name)
284 #define _FIND(name) \
285 name##_find
286 FIND(NAME) (htab, hval, val)
287 NAME *htab;
288 HASHTYPE hval;
289 TYPE val;
290 {
291 size_t idx;
292
293 /* Make the hash value nonzero. */
294 hval = hval ?: 1;
295
296 idx = lookup (htab, hval, val);
297
298 if (htab->table[idx].hashval == 0)
299 return NULL;
300
301 return htab->table[idx].data;
302 }
303
304
305 #ifdef ITERATE
306 # define ITERATEFCT(name) _ITERATEFCT (name)
307 # define _ITERATEFCT(name) \
308 name##_iterate
309 TYPE
310 ITERATEFCT(NAME) (htab, ptr)
311 NAME *htab;
312 void **ptr;
313 {
314 void *p = *ptr;
315
316 # define TYPENAME(name) _TYPENAME (name)
317 # define _TYPENAME(name) name##_ent
318
319 # ifdef REVERSE
320 if (p == NULL)
321 p = htab->first;
322 else
323 p = ((TYPENAME(NAME) *) p)->next;
324
325 if (p == NULL)
326 {
327 *ptr = NULL;
328 return NULL;
329 }
330 # else
331 if (p == NULL)
332 {
333 if (htab->first == NULL)
334 return NULL;
335 p = htab->first->next;
336 }
337 else
338 {
339 if (p == htab->first)
340 return NULL;
341
342 p = ((TYPENAME(NAME) *) p)->next;
343 }
344 # endif
345
346 /* Prepare the next element. If possible this will pull the data
347 into the cache, for reading. */
348 __builtin_prefetch (((TYPENAME(NAME) *) p)->next, 0, 2);
349
350 return ((TYPENAME(NAME) *) (*ptr = p))->data;
351 }
352 #endif
353