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comparison src/elhash.c @ 438:84b14dcb0985 r21-2-27

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Import from CVS: tag r21-2-27
author cvs
date Mon, 13 Aug 2007 11:32:25 +0200
parents 9d177e8d4150
children 8de8e3f6228a
comparison
equal deleted inserted replaced
437:e2a4e8b94b82 438:84b14dcb0985
411 /************************************************************************/ 411 /************************************************************************/
412 /* Creation of Hash Tables */ 412 /* Creation of Hash Tables */
413 /************************************************************************/ 413 /************************************************************************/
414 414
415 /* Creation of hash tables, without error-checking. */ 415 /* Creation of hash tables, without error-checking. */
416 static double
417 hash_table_rehash_threshold (Lisp_Hash_Table *ht)
418 {
419 return
420 ht->rehash_threshold > 0.0 ? ht->rehash_threshold :
421 ht->size > 4096 && !ht->test_function ? 0.7 : 0.6;
422 }
423
424 static void 416 static void
425 compute_hash_table_derived_values (Lisp_Hash_Table *ht) 417 compute_hash_table_derived_values (Lisp_Hash_Table *ht)
426 { 418 {
427 ht->rehash_count = (size_t) 419 ht->rehash_count = (size_t)
428 ((double) ht->size * hash_table_rehash_threshold (ht)); 420 ((double) ht->size * ht->rehash_threshold);
429 ht->golden_ratio = (size_t) 421 ht->golden_ratio = (size_t)
430 ((double) ht->size * (.6180339887 / (double) sizeof (Lisp_Object))); 422 ((double) ht->size * (.6180339887 / (double) sizeof (Lisp_Object)));
431 } 423 }
432 424
433 Lisp_Object 425 Lisp_Object
438 enum hash_table_weakness weakness) 430 enum hash_table_weakness weakness)
439 { 431 {
440 Lisp_Object hash_table; 432 Lisp_Object hash_table;
441 Lisp_Hash_Table *ht = alloc_lcrecord_type (Lisp_Hash_Table, &lrecord_hash_table); 433 Lisp_Hash_Table *ht = alloc_lcrecord_type (Lisp_Hash_Table, &lrecord_hash_table);
442 434
443 ht->rehash_size = rehash_size;
444 ht->rehash_threshold = rehash_threshold;
445 ht->weakness = weakness;
446
447 switch (test) 435 switch (test)
448 { 436 {
449 case HASH_TABLE_EQ: 437 case HASH_TABLE_EQ:
450 ht->test_function = 0; 438 ht->test_function = 0;
451 ht->hash_function = 0; 439 ht->hash_function = 0;
463 451
464 default: 452 default:
465 abort (); 453 abort ();
466 } 454 }
467 455
468 if (ht->rehash_size <= 0.0) 456 ht->weakness = weakness;
469 ht->rehash_size = HASH_TABLE_DEFAULT_REHASH_SIZE; 457
458 ht->rehash_size =
459 rehash_size > 1.0 ? rehash_size : HASH_TABLE_DEFAULT_REHASH_SIZE;
460
461 ht->rehash_threshold =
462 rehash_threshold > 0.0 ? rehash_threshold :
463 size > 4096 && !ht->test_function ? 0.7 : 0.6;
464
470 if (size < HASH_TABLE_MIN_SIZE) 465 if (size < HASH_TABLE_MIN_SIZE)
471 size = HASH_TABLE_MIN_SIZE; 466 size = HASH_TABLE_MIN_SIZE;
472 if (rehash_threshold < 0.0) 467 ht->size = hash_table_size ((size_t) (((double) size / ht->rehash_threshold)
473 rehash_threshold = 0.75; 468 + 1.0));
474 ht->size =
475 hash_table_size ((size_t) ((double) size / hash_table_rehash_threshold (ht)) + 1);
476 ht->count = 0; 469 ht->count = 0;
470
477 compute_hash_table_derived_values (ht); 471 compute_hash_table_derived_values (ht);
478 472
479 /* We leave room for one never-occupied sentinel hentry at the end. */ 473 /* We leave room for one never-occupied sentinel hentry at the end. */
480 ht->hentries = xnew_array (hentry, ht->size + 1); 474 ht->hentries = xnew_array (hentry, ht->size + 1);
481 475
498 Lisp_Object 492 Lisp_Object
499 make_lisp_hash_table (size_t size, 493 make_lisp_hash_table (size_t size,
500 enum hash_table_weakness weakness, 494 enum hash_table_weakness weakness,
501 enum hash_table_test test) 495 enum hash_table_test test)
502 { 496 {
503 return make_general_lisp_hash_table 497 return make_general_lisp_hash_table (test, size, -1.0, -1.0, weakness);
504 (test, size, HASH_TABLE_DEFAULT_REHASH_SIZE, -1.0, weakness);
505 } 498 }
506 499
507 /* Pretty reading of hash tables. 500 /* Pretty reading of hash tables.
508 501
509 Here we use the existing structures mechanism (which is, 502 Here we use the existing structures mechanism (which is,
1088 This is a float between 0.0 and 1.0; the maximum `load factor' of HASH-TABLE, 1081 This is a float between 0.0 and 1.0; the maximum `load factor' of HASH-TABLE,
1089 beyond which the HASH-TABLE is enlarged by rehashing. 1082 beyond which the HASH-TABLE is enlarged by rehashing.
1090 */ 1083 */
1091 (hash_table)) 1084 (hash_table))
1092 { 1085 {
1093 return make_float (hash_table_rehash_threshold (xhash_table (hash_table))); 1086 return make_float (xhash_table (hash_table)->rehash_threshold);
1094 } 1087 }
1095 1088
1096 DEFUN ("hash-table-weakness", Fhash_table_weakness, 1, 1, 0, /* 1089 DEFUN ("hash-table-weakness", Fhash_table_weakness, 1, 1, 0, /*
1097 Return the weakness of HASH-TABLE. 1090 Return the weakness of HASH-TABLE.
1098 This can be one of `nil', `t', `key' or `value'. 1091 This can be one of `nil', `t', `key' or `value'.