1 /* Sequential list data type implemented by a hash table with another list.
2 Copyright (C) 2006 Free Software Foundation, Inc.
3 Written by Bruno Haible <bruno@clisp.org>, 2006.
4
5 This program is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 2, or (at your option)
8 any later version.
9
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
14
15 You should have received a copy of the GNU General Public License
16 along with this program; if not, write to the Free Software Foundation,
17 Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
18
19 /* Common code of
20 gl_linkedhash_list.c, gl_avltreehash_list.c, gl_rbtreehash_list.c. */
21
22 /* Array of primes, approximately in steps of factor 1.2.
23 This table was computed by executing the Common Lisp expression
24 (dotimes (i 244) (format t "nextprime(~D)~%" (ceiling (expt 1.2d0 i))))
25 and feeding the result to PARI/gp. */
26 static const size_t primes[] =
27 {
28 11, 13, 17, 19, 23, 29, 37, 41, 47, 59, 67, 83, 97, 127, 139, 167, 199,
29 239, 293, 347, 419, 499, 593, 709, 853, 1021, 1229, 1471, 1777, 2129, 2543,
30 3049, 3659, 4391, 5273, 6323, 7589, 9103, 10937, 13109, 15727, 18899,
31 22651, 27179, 32609, 39133, 46957, 56359, 67619, 81157, 97369, 116849,
32 140221, 168253, 201907, 242309, 290761, 348889, 418667, 502409, 602887,
33 723467, 868151, 1041779, 1250141, 1500181, 1800191, 2160233, 2592277,
34 3110741, 3732887, 4479463, 5375371, 6450413, 7740517, 9288589, 11146307,
35 13375573, 16050689, 19260817, 23112977, 27735583, 33282701, 39939233,
36 47927081, 57512503, 69014987, 82818011, 99381577, 119257891, 143109469,
37 171731387, 206077643, 247293161, 296751781, 356102141, 427322587,
38 512787097, 615344489, 738413383, 886096061, 1063315271, 1275978331,
39 1531174013, 1837408799, 2204890543UL, 2645868653UL, 3175042391UL,
40 3810050851UL,
41 #if SIZE_MAX > 4294967295UL
42 4572061027UL, 5486473229UL, 6583767889UL, 7900521449UL, 9480625733UL,
43 11376750877UL, 13652101063UL, 16382521261UL, 19659025513UL, 23590830631UL,
44 28308996763UL, 33970796089UL, 40764955463UL, 48917946377UL, 58701535657UL,
45 70441842749UL, 84530211301UL, 101436253561UL, 121723504277UL,
46 146068205131UL, 175281846149UL, 210338215379UL, 252405858521UL,
47 302887030151UL, 363464436191UL, 436157323417UL, 523388788231UL,
48 628066545713UL, 753679854847UL, 904415825857UL, 1085298991109UL,
49 1302358789181UL, 1562830547009UL, 1875396656429UL, 2250475987709UL,
50 2700571185239UL, 3240685422287UL, 3888822506759UL, 4666587008147UL,
51 5599904409713UL, 6719885291641UL, 8063862349969UL, 9676634819959UL,
52 11611961783951UL, 13934354140769UL, 16721224968907UL, 20065469962669UL,
53 24078563955191UL, 28894276746229UL, 34673132095507UL, 41607758514593UL,
54 49929310217531UL, 59915172260971UL, 71898206713183UL, 86277848055823UL,
55 103533417666967UL, 124240101200359UL, 149088121440451UL, 178905745728529UL,
56 214686894874223UL, 257624273849081UL, 309149128618903UL, 370978954342639UL,
57 445174745211143UL, 534209694253381UL, 641051633104063UL, 769261959724877UL,
58 923114351670013UL, 1107737222003791UL, 1329284666404567UL,
59 1595141599685509UL, 1914169919622551UL, 2297003903547091UL,
60 2756404684256459UL, 3307685621107757UL, 3969222745329323UL,
61 4763067294395177UL, 5715680753274209UL, 6858816903929113UL,
62 8230580284714831UL, 9876696341657791UL, 11852035609989371UL,
63 14222442731987227UL, 17066931278384657UL, 20480317534061597UL,
64 24576381040873903UL, 29491657249048679UL, 35389988698858471UL,
65 42467986438630267UL, 50961583726356109UL, 61153900471627387UL,
66 73384680565952851UL, 88061616679143347UL, 105673940014972061UL,
67 126808728017966413UL, 152170473621559703UL, 182604568345871671UL,
68 219125482015045997UL, 262950578418055169UL, 315540694101666193UL,
69 378648832921999397UL, 454378599506399233UL, 545254319407679131UL,
70 654305183289214771UL, 785166219947057701UL, 942199463936469157UL,
71 1130639356723763129UL, 1356767228068515623UL, 1628120673682218619UL,
72 1953744808418662409UL, 2344493770102394881UL, 2813392524122873857UL,
73 3376071028947448339UL, 4051285234736937517UL, 4861542281684325481UL,
74 5833850738021191727UL, 7000620885625427969UL, 8400745062750513217UL,
75 10080894075300616261UL, 12097072890360739951UL, 14516487468432885797UL,
76 17419784962119465179UL,
77 #endif
78 SIZE_MAX /* sentinel, to ensure the search terminates */
79 };
80
81 /* Return a suitable prime >= ESTIMATE. */
82 static size_t
next_prime(size_t estimate)83 next_prime (size_t estimate)
84 {
85 size_t i;
86
87 for (i = 0; i < sizeof (primes) / sizeof (primes[0]); i++)
88 if (primes[i] >= estimate)
89 return primes[i];
90 return SIZE_MAX; /* not a prime, but better than nothing */
91 }
92
93 /* Resize the hash table with a new estimated size. */
94 static void
hash_resize(gl_list_t list,size_t estimate)95 hash_resize (gl_list_t list, size_t estimate)
96 {
97 size_t new_size = next_prime (estimate);
98
99 if (new_size > list->table_size)
100 {
101 gl_hash_entry_t *old_table = list->table;
102 /* Allocate the new table. */
103 gl_hash_entry_t *new_table =
104 (gl_hash_entry_t *) xzalloc (new_size * sizeof (gl_hash_entry_t));
105 size_t i;
106
107 /* Iterate through the entries of the old table. */
108 for (i = list->table_size; i > 0; )
109 {
110 gl_hash_entry_t node = old_table[--i];
111
112 while (node != NULL)
113 {
114 gl_hash_entry_t next = node->hash_next;
115 /* Add the entry to the new table. */
116 size_t bucket = node->hashcode % new_size;
117 node->hash_next = new_table[bucket];
118 new_table[bucket] = node;
119
120 node = next;
121 }
122 }
123
124 list->table = new_table;
125 list->table_size = new_size;
126 free (old_table);
127 }
128 }
129