lib/gl_anyhash_list2.h

   1 /* Sequential list data type implemented by a hash table with another list.
   2    Copyright (C) 2006, 2009-2018 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 3 of the License, or
   8    (at your option) 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, see <https://www.gnu.org/licenses/>.  */
  17
  18 /* Common code of
  19    gl_linkedhash_list.c, gl_avltreehash_list.c, gl_rbtreehash_list.c.  */
  20
  21 /* Array of primes, approximately in steps of factor 1.2.
  22    This table was computed by executing the Common Lisp expression
  23      (dotimes (i 244) (format t "nextprime(~D)~%" (ceiling (expt 1.2d0 i))))
  24    and feeding the result to PARI/gp.  */
  25 static const size_t primes[] =
  26   {
  27     11, 13, 17, 19, 23, 29, 37, 41, 47, 59, 67, 83, 97, 127, 139, 167, 199,
  28     239, 293, 347, 419, 499, 593, 709, 853, 1021, 1229, 1471, 1777, 2129, 2543,
  29     3049, 3659, 4391, 5273, 6323, 7589, 9103, 10937, 13109, 15727, 18899,
  30     22651, 27179, 32609, 39133, 46957, 56359, 67619, 81157, 97369, 116849,
  31     140221, 168253, 201907, 242309, 290761, 348889, 418667, 502409, 602887,
  32     723467, 868151, 1041779, 1250141, 1500181, 1800191, 2160233, 2592277,
  33     3110741, 3732887, 4479463, 5375371, 6450413, 7740517, 9288589, 11146307,
  34     13375573, 16050689, 19260817, 23112977, 27735583, 33282701, 39939233,
  35     47927081, 57512503, 69014987, 82818011, 99381577, 119257891, 143109469,
  36     171731387, 206077643, 247293161, 296751781, 356102141, 427322587,
  37     512787097, 615344489, 738413383, 886096061, 1063315271, 1275978331,
  38     1531174013, 1837408799, 2204890543UL, 2645868653UL, 3175042391UL,
  39     3810050851UL,
  40 #if SIZE_MAX > 4294967295UL
  41     4572061027UL, 5486473229UL, 6583767889UL, 7900521449UL, 9480625733UL,
  42     11376750877UL, 13652101063UL, 16382521261UL, 19659025513UL, 23590830631UL,
  43     28308996763UL, 33970796089UL, 40764955463UL, 48917946377UL, 58701535657UL,
  44     70441842749UL, 84530211301UL, 101436253561UL, 121723504277UL,
  45     146068205131UL, 175281846149UL, 210338215379UL, 252405858521UL,
  46     302887030151UL, 363464436191UL, 436157323417UL, 523388788231UL,
  47     628066545713UL, 753679854847UL, 904415825857UL, 1085298991109UL,
  48     1302358789181UL, 1562830547009UL, 1875396656429UL, 2250475987709UL,
  49     2700571185239UL, 3240685422287UL, 3888822506759UL, 4666587008147UL,
  50     5599904409713UL, 6719885291641UL, 8063862349969UL, 9676634819959UL,
  51     11611961783951UL, 13934354140769UL, 16721224968907UL, 20065469962669UL,
  52     24078563955191UL, 28894276746229UL, 34673132095507UL, 41607758514593UL,
  53     49929310217531UL, 59915172260971UL, 71898206713183UL, 86277848055823UL,
  54     103533417666967UL, 124240101200359UL, 149088121440451UL, 178905745728529UL,
  55     214686894874223UL, 257624273849081UL, 309149128618903UL, 370978954342639UL,
  56     445174745211143UL, 534209694253381UL, 641051633104063UL, 769261959724877UL,
  57     923114351670013UL, 1107737222003791UL, 1329284666404567UL,
  58     1595141599685509UL, 1914169919622551UL, 2297003903547091UL,
  59     2756404684256459UL, 3307685621107757UL, 3969222745329323UL,
  60     4763067294395177UL, 5715680753274209UL, 6858816903929113UL,
  61     8230580284714831UL, 9876696341657791UL, 11852035609989371UL,
  62     14222442731987227UL, 17066931278384657UL, 20480317534061597UL,
  63     24576381040873903UL, 29491657249048679UL, 35389988698858471UL,
  64     42467986438630267UL, 50961583726356109UL, 61153900471627387UL,
  65     73384680565952851UL, 88061616679143347UL, 105673940014972061UL,
  66     126808728017966413UL, 152170473621559703UL, 182604568345871671UL,
  67     219125482015045997UL, 262950578418055169UL, 315540694101666193UL,
  68     378648832921999397UL, 454378599506399233UL, 545254319407679131UL,
  69     654305183289214771UL, 785166219947057701UL, 942199463936469157UL,
  70     1130639356723763129UL, 1356767228068515623UL, 1628120673682218619UL,
  71     1953744808418662409UL, 2344493770102394881UL, 2813392524122873857UL,
  72     3376071028947448339UL, 4051285234736937517UL, 4861542281684325481UL,
  73     5833850738021191727UL, 7000620885625427969UL, 8400745062750513217UL,
  74     10080894075300616261UL, 12097072890360739951UL, 14516487468432885797UL,
  75     17419784962119465179UL,
  76 #endif
  77     SIZE_MAX /* sentinel, to ensure the search terminates */
  78   };
  79
  80 /* Return a suitable prime >= ESTIMATE.  */
  81 static size_t
  82 next_prime (size_t estimate)
  83 {
  84   size_t i;
  85
  86   for (i = 0; i < sizeof (primes) / sizeof (primes[0]); i++)
  87     if (primes[i] >= estimate)
  88       return primes[i];
  89   return SIZE_MAX; /* not a prime, but better than nothing */
  90 }
  91
  92 /* Resize the hash table with a new estimated size.  */
  93 static void
  94 hash_resize (gl_list_t list, size_t estimate)
  95 {
  96   size_t new_size = next_prime (estimate);
  97
  98   if (new_size > list->table_size)
  99     {
 100       gl_hash_entry_t *old_table = list->table;
 101       /* Allocate the new table.  */
 102       gl_hash_entry_t *new_table;
 103       size_t i;
 104
 105       if (size_overflow_p (xtimes (new_size, sizeof (gl_hash_entry_t))))
 106         goto fail;
 107       new_table =
 108         (gl_hash_entry_t *) calloc (new_size, sizeof (gl_hash_entry_t));
 109       if (new_table == NULL)
 110         goto fail;
 111
 112       /* Iterate through the entries of the old table.  */
 113       for (i = list->table_size; i > 0; )
 114         {
 115           gl_hash_entry_t node = old_table[--i];
 116
 117           while (node != NULL)
 118             {
 119               gl_hash_entry_t next = node->hash_next;
 120               /* Add the entry to the new table.  */
 121               size_t bucket = node->hashcode % new_size;
 122               node->hash_next = new_table[bucket];
 123               new_table[bucket] = node;
 124
 125               node = next;
 126             }
 127         }
 128
 129       list->table = new_table;
 130       list->table_size = new_size;
 131       free (old_table);
 132     }
 133   return;
 134
 135  fail:
 136   /* Just continue without resizing the table.  */
 137   return;
 138 }