1 /* Copyright (C) 2000, 2001, 2002, 2005 Red Hat, Inc. 2 This file is part of Red Hat elfutils. 3 Written by Ulrich Drepper <drepper (at) 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 68 lookup (htab, hval, val) 69 NAME *htab; 70 unsigned long int 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 unsigned long int 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 106 insert_entry_2 (NAME *htab, unsigned long int 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 unsigned long int 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 unsigned long int 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 unsigned long int 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 unsigned long int 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 unsigned long int 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
