Mercurial > hg > xemacs-beta
annotate src/hash.c @ 5149:b72f27a08ed5
Reflect --with-datadir setting in late-package directories.
2010-03-18 Mike Sperber <mike@xemacs.org>
* configure.ac: Set LATE_PACKAGE_DIRECTORIES_USER_DEFINED if
`datadir' was changed; set `with_late_packages' to something
sensible for this case.
| author | Mike Sperber <sperber@deinprogramm.de> |
|---|---|
| date | Thu, 18 Mar 2010 13:42:29 +0100 |
| parents | 88bd4f3ef8e4 |
| children | 308d34e9f07d |
| rev | line source |
|---|---|
| 428 | 1 /* Hash tables. |
| 2 Copyright (C) 1992, 1993, 1994 Free Software Foundation, Inc. | |
|
5146
88bd4f3ef8e4
make lrecord UID's have a separate UID space for each object, resurrect debug SOE code in extents.c
Ben Wing <ben@xemacs.org>
parents:
4976
diff
changeset
|
3 Copyright (C) 2003, 2004, 2010 Ben Wing. |
| 428 | 4 |
| 5 This file is part of XEmacs. | |
| 6 | |
| 7 XEmacs is free software; you can redistribute it and/or modify it | |
| 8 under the terms of the GNU General Public License as published by the | |
| 9 Free Software Foundation; either version 2, or (at your option) any | |
| 10 later version. | |
| 11 | |
| 12 XEmacs is distributed in the hope that it will be useful, but WITHOUT | |
| 13 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
| 14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
| 15 for more details. | |
| 16 | |
| 17 You should have received a copy of the GNU General Public License | |
| 18 along with XEmacs; see the file COPYING. If not, write to | |
| 19 the Free Software Foundation, Inc., 59 Temple Place - Suite 330, | |
| 20 Boston, MA 02111-1307, USA. */ | |
| 21 | |
| 22 /* Synched up with: Not in FSF. */ | |
| 23 | |
| 1292 | 24 /* Author: Lost in the mists of history. At least back to Lucid 19.3, |
| 25 circa Sep 1992. */ | |
| 26 | |
| 428 | 27 #include <config.h> |
| 28 #include "lisp.h" | |
| 29 #include "hash.h" | |
| 30 | |
|
5146
88bd4f3ef8e4
make lrecord UID's have a separate UID space for each object, resurrect debug SOE code in extents.c
Ben Wing <ben@xemacs.org>
parents:
4976
diff
changeset
|
31 #define NULL_ENTRY ((void *) 0xDEADBEEF) /* -559038737 base 10 */ |
| 428 | 32 |
| 33 #define COMFORTABLE_SIZE(size) (21 * (size) / 16) | |
| 34 | |
| 3025 | 35 #define KEYS_DIFFER_P(old, new_, testfun) \ |
| 36 (((old) != (new_)) && (!(testfun) || !(testfun) ((old),(new_)))) | |
| 428 | 37 |
| 665 | 38 static void rehash (hentry *harray, struct hash_table *ht, Elemcount size); |
| 428 | 39 |
| 665 | 40 Hashcode |
| 41 memory_hash (const void *xv, Bytecount size) | |
| 428 | 42 { |
| 665 | 43 Hashcode h = 0; |
| 442 | 44 unsigned const char *x = (unsigned const char *) xv; |
| 428 | 45 |
| 46 if (!x) return 0; | |
| 47 | |
| 48 while (size--) | |
| 49 { | |
| 665 | 50 Hashcode g; |
| 428 | 51 h = (h << 4) + *x++; |
| 52 if ((g = h & 0xf0000000) != 0) | |
| 53 h = (h ^ (g >> 24)) ^ g; | |
| 54 } | |
| 55 | |
| 56 return h; | |
| 57 } | |
| 58 | |
| 2515 | 59 static int |
| 60 string_equal (const void *st1, const void *st2) | |
| 61 { | |
| 62 if (!st1) | |
| 63 return st2 ? 0 : 1; | |
| 64 else if (!st2) | |
| 65 return 0; | |
| 66 else | |
| 67 return !strcmp ((const char *) st1, (const char *) st2); | |
| 68 } | |
| 69 | |
| 70 static Hashcode | |
| 71 string_hash (const void *xv) | |
| 442 | 72 { |
| 665 | 73 Hashcode h = 0; |
| 442 | 74 unsigned const char *x = (unsigned const char *) xv; |
| 75 | |
| 76 if (!x) return 0; | |
| 77 | |
| 78 while (*x) | |
| 79 { | |
| 665 | 80 Hashcode g; |
| 442 | 81 h = (h << 4) + *x++; |
| 82 if ((g = h & 0xf0000000) != 0) | |
| 83 h = (h ^ (g >> 24)) ^ g; | |
| 84 } | |
| 85 | |
| 86 return h; | |
| 87 } | |
| 88 | |
| 428 | 89 /* Return a suitable size for a hash table, with at least SIZE slots. */ |
| 665 | 90 static Elemcount |
| 91 hash_table_size (Elemcount requested_size) | |
| 428 | 92 { |
| 93 /* Return some prime near, but greater than or equal to, SIZE. | |
| 94 Decades from the time of writing, someone will have a system large | |
| 95 enough that the list below will be too short... */ | |
| 665 | 96 static const Elemcount primes [] = |
| 428 | 97 { |
| 98 19, 29, 41, 59, 79, 107, 149, 197, 263, 347, 457, 599, 787, 1031, | |
| 99 1361, 1777, 2333, 3037, 3967, 5167, 6719, 8737, 11369, 14783, | |
| 100 19219, 24989, 32491, 42257, 54941, 71429, 92861, 120721, 156941, | |
| 101 204047, 265271, 344857, 448321, 582821, 757693, 985003, 1280519, | |
| 102 1664681, 2164111, 2813353, 3657361, 4754591, 6180989, 8035301, | |
| 103 10445899, 13579681, 17653589, 22949669, 29834603, 38784989, | |
| 104 50420551, 65546729, 85210757, 110774011, 144006217, 187208107, | |
| 105 243370577, 316381771, 411296309, 534685237, 695090819, 903618083, | |
| 647 | 106 1174703521, 1527114613, 1985248999 /* , 2580823717UL, 3355070839UL */ |
| 428 | 107 }; |
| 108 /* We've heard of binary search. */ | |
| 109 int low, high; | |
| 110 for (low = 0, high = countof (primes) - 1; high - low > 1;) | |
| 111 { | |
| 112 /* Loop Invariant: size < primes [high] */ | |
| 113 int mid = (low + high) / 2; | |
| 114 if (primes [mid] < requested_size) | |
| 115 low = mid; | |
| 116 else | |
| 117 high = mid; | |
| 118 } | |
| 119 return primes [high]; | |
| 120 } | |
| 121 | |
| 442 | 122 const void * |
| 123 gethash (const void *key, struct hash_table *hash_table, const void **ret_value) | |
| 428 | 124 { |
| 125 if (!key) | |
| 126 { | |
| 127 *ret_value = hash_table->zero_entry; | |
| 128 return (void *) hash_table->zero_set; | |
| 129 } | |
| 130 else | |
| 131 { | |
| 132 hentry *harray = hash_table->harray; | |
| 133 hash_table_test_function test_function = hash_table->test_function; | |
| 665 | 134 Elemcount size = hash_table->size; |
| 135 Hashcode hcode_initial = | |
| 428 | 136 hash_table->hash_function ? |
| 137 hash_table->hash_function (key) : | |
| 665 | 138 (Hashcode) key; |
| 139 Elemcount hcode = (Elemcount) (hcode_initial % size); | |
| 428 | 140 hentry *e = &harray [hcode]; |
| 442 | 141 const void *e_key = e->key; |
| 428 | 142 |
| 143 if (e_key ? | |
| 144 KEYS_DIFFER_P (e_key, key, test_function) : | |
| 145 e->contents == NULL_ENTRY) | |
| 146 { | |
| 665 | 147 Elemcount h2 = size - 2; |
| 148 Elemcount incr = (Elemcount) (1 + (hcode_initial % h2)); | |
| 428 | 149 do |
| 150 { | |
| 151 hcode += incr; if (hcode >= size) hcode -= size; | |
| 152 e = &harray [hcode]; | |
| 153 e_key = e->key; | |
| 154 } | |
| 155 while (e_key ? | |
| 156 KEYS_DIFFER_P (e_key, key, test_function) : | |
| 157 e->contents == NULL_ENTRY); | |
| 158 } | |
| 159 | |
| 160 *ret_value = e->contents; | |
| 161 return e->key; | |
| 162 } | |
| 163 } | |
| 164 | |
| 165 void | |
| 166 clrhash (struct hash_table *hash_table) | |
| 167 { | |
| 168 memset (hash_table->harray, 0, sizeof (hentry) * hash_table->size); | |
| 169 hash_table->zero_entry = 0; | |
| 170 hash_table->zero_set = 0; | |
| 171 hash_table->fullness = 0; | |
| 172 } | |
| 173 | |
| 174 void | |
| 175 free_hash_table (struct hash_table *hash_table) | |
| 176 { | |
|
4976
16112448d484
Rename xfree(FOO, TYPE) -> xfree(FOO)
Ben Wing <ben@xemacs.org>
parents:
3025
diff
changeset
|
177 xfree (hash_table->harray); |
|
16112448d484
Rename xfree(FOO, TYPE) -> xfree(FOO)
Ben Wing <ben@xemacs.org>
parents:
3025
diff
changeset
|
178 xfree (hash_table); |
| 428 | 179 } |
| 180 | |
| 2515 | 181 struct hash_table * |
| 665 | 182 make_hash_table (Elemcount size) |
| 428 | 183 { |
| 184 struct hash_table *hash_table = xnew_and_zero (struct hash_table); | |
| 185 hash_table->size = hash_table_size (COMFORTABLE_SIZE (size)); | |
| 186 hash_table->harray = xnew_array (hentry, hash_table->size); | |
| 187 clrhash (hash_table); | |
| 188 return hash_table; | |
| 189 } | |
| 190 | |
| 191 struct hash_table * | |
| 2515 | 192 make_string_hash_table (Elemcount size) |
| 193 { | |
| 194 return make_general_hash_table (size, string_hash, string_equal); | |
| 195 } | |
| 196 | |
| 197 struct hash_table * | |
| 665 | 198 make_general_hash_table (Elemcount size, |
| 428 | 199 hash_table_hash_function hash_function, |
| 200 hash_table_test_function test_function) | |
| 201 { | |
| 202 struct hash_table* hash_table = make_hash_table (size); | |
| 203 hash_table->hash_function = hash_function; | |
| 204 hash_table->test_function = test_function; | |
| 205 return hash_table; | |
| 206 } | |
| 207 | |
| 208 static void | |
| 665 | 209 grow_hash_table (struct hash_table *hash_table, Elemcount new_size) |
| 428 | 210 { |
| 665 | 211 Elemcount old_size = hash_table->size; |
| 428 | 212 hentry *old_harray = hash_table->harray; |
| 213 | |
| 214 hash_table->size = hash_table_size (new_size); | |
| 215 hash_table->harray = xnew_array (hentry, hash_table->size); | |
| 216 | |
| 217 /* do the rehash on the "grown" table */ | |
| 218 { | |
| 219 long old_zero_set = hash_table->zero_set; | |
| 220 void *old_zero_entry = hash_table->zero_entry; | |
| 221 clrhash (hash_table); | |
| 222 hash_table->zero_set = old_zero_set; | |
| 223 hash_table->zero_entry = old_zero_entry; | |
| 224 rehash (old_harray, hash_table, old_size); | |
| 225 } | |
| 226 | |
|
4976
16112448d484
Rename xfree(FOO, TYPE) -> xfree(FOO)
Ben Wing <ben@xemacs.org>
parents:
3025
diff
changeset
|
227 xfree (old_harray); |
| 428 | 228 } |
| 229 | |
| 230 void | |
| 1292 | 231 pregrow_hash_table_if_necessary (struct hash_table *hash_table, |
| 232 Elemcount breathing_room) | |
| 233 { | |
| 234 Elemcount comfortable_size = COMFORTABLE_SIZE (hash_table->fullness); | |
| 235 if (hash_table->size < comfortable_size - breathing_room) | |
| 236 grow_hash_table (hash_table, comfortable_size + 1); | |
| 237 } | |
| 238 | |
| 239 void | |
| 442 | 240 puthash (const void *key, void *contents, struct hash_table *hash_table) |
| 428 | 241 { |
| 242 if (!key) | |
| 243 { | |
| 244 hash_table->zero_entry = contents; | |
| 245 hash_table->zero_set = 1; | |
| 246 } | |
| 247 else | |
| 248 { | |
| 249 hash_table_test_function test_function = hash_table->test_function; | |
| 665 | 250 Elemcount size = hash_table->size; |
| 428 | 251 hentry *harray = hash_table->harray; |
| 665 | 252 Hashcode hcode_initial = |
| 428 | 253 hash_table->hash_function ? |
| 254 hash_table->hash_function (key) : | |
| 665 | 255 (Hashcode) key; |
| 256 Elemcount hcode = (Elemcount) (hcode_initial % size); | |
| 257 Elemcount h2 = size - 2; | |
| 258 Elemcount incr = (Elemcount) (1 + (hcode_initial % h2)); | |
| 442 | 259 const void *e_key = harray [hcode].key; |
| 260 const void *oldcontents; | |
| 428 | 261 |
| 262 if (e_key && KEYS_DIFFER_P (e_key, key, test_function)) | |
| 263 { | |
| 264 do | |
| 265 { | |
| 266 hcode += incr; if (hcode >= size) hcode -= size; | |
| 267 e_key = harray [hcode].key; | |
| 268 } | |
| 269 while (e_key && KEYS_DIFFER_P (e_key, key, test_function)); | |
| 270 } | |
| 271 oldcontents = harray [hcode].contents; | |
| 272 harray [hcode].key = key; | |
| 273 harray [hcode].contents = contents; | |
| 274 /* If the entry that we used was a deleted entry, | |
| 275 check for a non deleted entry of the same key, | |
| 276 then delete it. */ | |
| 277 if (!e_key && oldcontents == NULL_ENTRY) | |
| 278 { | |
| 279 hentry *e; | |
| 280 | |
| 281 do | |
| 282 { | |
| 283 hcode += incr; if (hcode >= size) hcode -= size; | |
| 284 e = &harray [hcode]; | |
| 285 e_key = e->key; | |
| 286 } | |
| 287 while (e_key ? | |
| 288 KEYS_DIFFER_P (e_key, key, test_function): | |
| 289 e->contents == NULL_ENTRY); | |
| 290 | |
| 291 if (e_key) | |
| 292 { | |
| 293 e->key = 0; | |
| 294 e->contents = NULL_ENTRY; | |
| 295 } | |
| 296 } | |
| 297 | |
| 298 /* only increment the fullness when we used up a new hentry */ | |
| 299 if (!e_key || KEYS_DIFFER_P (e_key, key, test_function)) | |
| 300 { | |
| 665 | 301 Elemcount comfortable_size = COMFORTABLE_SIZE (++(hash_table->fullness)); |
| 428 | 302 if (hash_table->size < comfortable_size) |
| 303 grow_hash_table (hash_table, comfortable_size + 1); | |
| 304 } | |
| 305 } | |
| 306 } | |
| 307 | |
| 308 static void | |
| 665 | 309 rehash (hentry *harray, struct hash_table *hash_table, Elemcount size) |
| 428 | 310 { |
| 311 hentry *limit = harray + size; | |
| 312 hentry *e; | |
| 313 for (e = harray; e < limit; e++) | |
| 314 { | |
| 315 if (e->key) | |
| 316 puthash (e->key, e->contents, hash_table); | |
| 317 } | |
| 318 } | |
| 319 | |
| 320 void | |
| 442 | 321 remhash (const void *key, struct hash_table *hash_table) |
| 428 | 322 { |
| 323 if (!key) | |
| 324 { | |
| 325 hash_table->zero_entry = 0; | |
| 326 hash_table->zero_set = 0; | |
| 327 } | |
| 328 else | |
| 329 { | |
| 330 hentry *harray = hash_table->harray; | |
| 331 hash_table_test_function test_function = hash_table->test_function; | |
| 665 | 332 Elemcount size = hash_table->size; |
| 333 Hashcode hcode_initial = | |
| 428 | 334 (hash_table->hash_function) ? |
| 335 (hash_table->hash_function (key)) : | |
| 665 | 336 ((Hashcode) key); |
| 337 Elemcount hcode = (Elemcount) (hcode_initial % size); | |
| 428 | 338 hentry *e = &harray [hcode]; |
| 442 | 339 const void *e_key = e->key; |
| 428 | 340 |
| 341 if (e_key ? | |
| 342 KEYS_DIFFER_P (e_key, key, test_function) : | |
| 343 e->contents == NULL_ENTRY) | |
| 344 { | |
| 665 | 345 Elemcount h2 = size - 2; |
| 346 Elemcount incr = (Elemcount) (1 + (hcode_initial % h2)); | |
| 428 | 347 do |
| 348 { | |
| 349 hcode += incr; if (hcode >= size) hcode -= size; | |
| 350 e = &harray [hcode]; | |
| 351 e_key = e->key; | |
| 352 } | |
| 353 while (e_key? | |
| 354 KEYS_DIFFER_P (e_key, key, test_function): | |
| 355 e->contents == NULL_ENTRY); | |
| 356 } | |
| 357 if (e_key) | |
| 358 { | |
| 359 e->key = 0; | |
| 360 e->contents = NULL_ENTRY; | |
| 361 /* Note: you can't do fullness-- here, it breaks the world. */ | |
| 362 } | |
| 363 } | |
| 364 } | |
| 365 | |
| 366 void | |
| 367 maphash (maphash_function mf, struct hash_table *hash_table, void *arg) | |
| 368 { | |
| 369 hentry *e; | |
| 370 hentry *limit; | |
| 371 | |
| 372 if (hash_table->zero_set) | |
| 373 { | |
| 374 if (mf (0, hash_table->zero_entry, arg)) | |
| 375 return; | |
| 376 } | |
| 377 | |
| 378 for (e = hash_table->harray, limit = e + hash_table->size; e < limit; e++) | |
| 379 { | |
| 380 if (e->key && mf (e->key, e->contents, arg)) | |
| 381 return; | |
| 382 } | |
| 383 } | |
| 384 | |
| 385 void | |
| 386 map_remhash (remhash_predicate predicate, struct hash_table *hash_table, void *arg) | |
| 387 { | |
| 388 hentry *e; | |
| 389 hentry *limit; | |
| 390 | |
| 391 if (hash_table->zero_set && predicate (0, hash_table->zero_entry, arg)) | |
| 392 { | |
| 393 hash_table->zero_set = 0; | |
| 394 hash_table->zero_entry = 0; | |
| 395 } | |
| 396 | |
| 397 for (e = hash_table->harray, limit = e + hash_table->size; e < limit; e++) | |
| 398 if (predicate (e->key, e->contents, arg)) | |
| 399 { | |
| 400 e->key = 0; | |
| 401 e->contents = NULL_ENTRY; | |
| 402 } | |
| 403 } |