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comparison src/elhash.c @ 4777:c69aeb86b2a3

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Serialise non-default hash table rehash thresholds correctly; use this. src/ChangeLog addition: 2009-12-17 Aidan Kehoe <kehoea@parhasard.net> * elhash.c (HASH_TABLE_DEFAULT_REHASH_THRESHOLD): New macro, giving a default value for a hash table's rehash threshold given its size and test function. (print_hash_table): Print the hash table's rehash threshold if it has a non-default value. Ditto for its rehash size. (Fmake_hash_table): Supply the keyword arguments in a format understood by #'function-arglist. lisp/ChangeLog addition: 2009-12-17 Aidan Kehoe <kehoea@parhasard.net> * mule/make-coding-system.el (fixed-width-create-decode-encode-tables): Use a rehash threshold of 0.999 for this hash table, now that hash table rehash thresholds are serialised correctly; these hash tables will never be resized, and it's not even that important that they are *that* fast, for most of the coding systems they're used a minority of the time.
author Aidan Kehoe <kehoea@parhasard.net>
date Thu, 17 Dec 2009 13:50:45 +0000
parents 80cd90837ac5
children 0081fd36b783
comparison
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4776:73e8632018ad 4777:c69aeb86b2a3
116 (*(EMACS_UINT*)(&((htentry)->value))) = 0) 116 (*(EMACS_UINT*)(&((htentry)->value))) = 0)
117 117
118 #define HASH_TABLE_DEFAULT_SIZE 16 118 #define HASH_TABLE_DEFAULT_SIZE 16
119 #define HASH_TABLE_DEFAULT_REHASH_SIZE 1.3 119 #define HASH_TABLE_DEFAULT_REHASH_SIZE 1.3
120 #define HASH_TABLE_MIN_SIZE 10 120 #define HASH_TABLE_MIN_SIZE 10
121 #define HASH_TABLE_DEFAULT_REHASH_THRESHOLD(size, test_function) \
122 ((size) > 4096 && (test_function) == HASH_TABLE_EQ ? 0.7 : 0.6)
121 123
122 #define HASHCODE(key, ht) \ 124 #define HASHCODE(key, ht) \
123 ((((ht)->hash_function ? (ht)->hash_function (key) : LISP_HASH (key)) \ 125 ((((ht)->hash_function ? (ht)->hash_function (key) : LISP_HASH (key)) \
124 * (ht)->golden_ratio) \ 126 * (ht)->golden_ratio) \
125 % (ht)->size) 127 % (ht)->size)
351 static void 353 static void
352 print_hash_table (Lisp_Object obj, Lisp_Object printcharfun, 354 print_hash_table (Lisp_Object obj, Lisp_Object printcharfun,
353 int UNUSED (escapeflag)) 355 int UNUSED (escapeflag))
354 { 356 {
355 Lisp_Hash_Table *ht = XHASH_TABLE (obj); 357 Lisp_Hash_Table *ht = XHASH_TABLE (obj);
358 Ascbyte pigbuf[350];
356 359
357 write_c_string (printcharfun, 360 write_c_string (printcharfun,
358 print_readably ? "#s(hash-table" : "#<hash-table"); 361 print_readably ? "#s(hash-table" : "#<hash-table");
359 362
360 /* These checks have a kludgy look to them, but they are safe. 363 /* These checks have a kludgy look to them, but they are safe.
385 (ht->weakness == HASH_TABLE_WEAK ? "key-and-value" : 388 (ht->weakness == HASH_TABLE_WEAK ? "key-and-value" :
386 ht->weakness == HASH_TABLE_KEY_WEAK ? "key" : 389 ht->weakness == HASH_TABLE_KEY_WEAK ? "key" :
387 ht->weakness == HASH_TABLE_VALUE_WEAK ? "value" : 390 ht->weakness == HASH_TABLE_VALUE_WEAK ? "value" :
388 ht->weakness == HASH_TABLE_KEY_VALUE_WEAK ? "key-or-value" : 391 ht->weakness == HASH_TABLE_KEY_VALUE_WEAK ? "key-or-value" :
389 "you-d-better-not-see-this")); 392 "you-d-better-not-see-this"));
393 }
394
395 if (ht->rehash_size != HASH_TABLE_DEFAULT_REHASH_SIZE)
396 {
397 float_to_string (pigbuf, ht->rehash_size);
398 write_fmt_string (printcharfun, " rehash-size %s", pigbuf);
399 }
400
401 if (ht->rehash_threshold
402 != HASH_TABLE_DEFAULT_REHASH_THRESHOLD (ht->size,
403 ht->test_function))
404 {
405 float_to_string (pigbuf, ht->rehash_threshold);
406 write_fmt_string (printcharfun, " rehash-threshold %s", pigbuf);
390 } 407 }
391 408
392 if (ht->count) 409 if (ht->count)
393 print_hash_table_data (ht, printcharfun); 410 print_hash_table_data (ht, printcharfun);
394 411
589 ht->rehash_size = 606 ht->rehash_size =
590 rehash_size > 1.0 ? rehash_size : HASH_TABLE_DEFAULT_REHASH_SIZE; 607 rehash_size > 1.0 ? rehash_size : HASH_TABLE_DEFAULT_REHASH_SIZE;
591 608
592 ht->rehash_threshold = 609 ht->rehash_threshold =
593 rehash_threshold > 0.0 ? rehash_threshold : 610 rehash_threshold > 0.0 ? rehash_threshold :
594 size > 4096 && !ht->test_function ? 0.7 : 0.6; 611 HASH_TABLE_DEFAULT_REHASH_THRESHOLD (size, ht->test_function);
595 612
596 if (size < HASH_TABLE_MIN_SIZE) 613 if (size < HASH_TABLE_MIN_SIZE)
597 size = HASH_TABLE_MIN_SIZE; 614 size = HASH_TABLE_MIN_SIZE;
598 ht->size = hash_table_size ((Elemcount) (((double) size / ht->rehash_threshold) 615 ht->size = hash_table_size ((Elemcount) (((double) size / ht->rehash_threshold)
599 + 1.0)); 616 + 1.0));
910 } 927 }
911 928
912 DEFUN ("make-hash-table", Fmake_hash_table, 0, MANY, 0, /* 929 DEFUN ("make-hash-table", Fmake_hash_table, 0, MANY, 0, /*
913 Return a new empty hash table object. 930 Return a new empty hash table object.
914 Use Common Lisp style keywords to specify hash table properties. 931 Use Common Lisp style keywords to specify hash table properties.
915 (make-hash-table &key test size rehash-size rehash-threshold weakness)
916 932
917 Keyword :test can be `eq', `eql' (default) or `equal'. 933 Keyword :test can be `eq', `eql' (default) or `equal'.
918 Comparison between keys is done using this function. 934 Comparison between keys is done using this function.
919 If speed is important, consider using `eq'. 935 If speed is important, consider using `eq'.
920 When storing strings in the hash table, you will likely need to use `equal'. 936 When storing strings in the hash table, you will likely need to use `equal'.
955 that a key-value pair will be removed only if the value and the key remain 971 that a key-value pair will be removed only if the value and the key remain
956 unmarked outside of weak hash tables. The pair will remain in the 972 unmarked outside of weak hash tables. The pair will remain in the
957 hash table if the value or key are pointed to by something other than a weak 973 hash table if the value or key are pointed to by something other than a weak
958 hash table, even if the other is not. 974 hash table, even if the other is not.
959 975
960 arguments: (&rest ARGS) 976 arguments: (&key TEST SIZE REHASH-SIZE REHASH-THRESHOLD WEAKNESS)
961 */ 977 */
962 (int nargs, Lisp_Object *args)) 978 (int nargs, Lisp_Object *args))
963 { 979 {
964 int i = 0; 980 int i = 0;
965 Lisp_Object test = Qnil; 981 Lisp_Object test = Qnil;