lib/hash.h

   1 /* hash.h -- decls for hash table
   2    Copyright 1995, 2001  Free Software Foundation, Inc.
   3    Written by Greg McGary <gkm@gnu.ai.mit.edu>
   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
  17    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
  18
  19 #ifndef _hash_h_
  20 #define _hash_h_
  21
  22 #include <stdio.h>
  23
  24 typedef unsigned long (*hash_func_t) __P((void const *key));
  25 typedef int (*hash_cmp_func_t) __P((void const *x, void const *y));
  26 typedef void (*hash_map_func_t) __P((void const *item));
  27
  28 struct hash_table
  29 {
  30   void **ht_vec;
  31   unsigned long ht_size;        /* total number of slots (power of 2) */
  32   unsigned long ht_capacity;    /* usable slots, limited by loading-factor */
  33   unsigned long ht_fill;        /* items in table */
  34   unsigned long ht_collisions;  /* # of failed calls to comparison function */
  35   unsigned long ht_lookups;     /* # of queries */
  36   unsigned int ht_rehashes;     /* # of times we've expanded table */
  37   hash_func_t ht_hash_1;        /* primary hash function */
  38   hash_func_t ht_hash_2;        /* secondary hash function */
  39   hash_cmp_func_t ht_compare;   /* comparison function */
  40 };
  41
  42 typedef int (*qsort_cmp_t) __P((void const *, void const *));
  43
  44 void hash_init __P((struct hash_table *ht, unsigned long size,
  45                     hash_func_t hash_1, hash_func_t hash_2, hash_cmp_func_t hash_cmp));
  46 void hash_load __P((struct hash_table *ht, void *item_table,
  47                     unsigned long cardinality, unsigned long size));
  48 void **hash_find_slot __P((struct hash_table *ht, void const *key));
  49 void *hash_find_item __P((struct hash_table *ht, void const *key));
  50 const void *hash_insert __P((struct hash_table *ht, void *item));
  51 const void *hash_insert_at __P((struct hash_table *ht, void *item, void const *slot));
  52 const void *hash_delete __P((struct hash_table *ht, void const *item));
  53 const void *hash_delete_at __P((struct hash_table *ht, void const *slot));
  54 void hash_delete_items __P((struct hash_table *ht));
  55 void hash_free_items __P((struct hash_table *ht));
  56 void hash_free __P((struct hash_table *ht, int free_items));
  57 void hash_map __P((struct hash_table *ht, hash_map_func_t map));
  58 void hash_print_stats __P((struct hash_table *ht, FILE *out_FILE));
  59 void **hash_dump __P((struct hash_table *ht, void **vector_0, qsort_cmp_t compare));
  60
  61 extern void *hash_deleted_item;
  62 #define HASH_VACANT(item) \
  63    ((item) == 0 || (const void *) (item) == hash_deleted_item)
  64
  65 \f
  66 /* hash and comparison macros for string keys. */
  67
  68 #define STRING_HASH_1(_key_, _result_) { \
  69   unsigned char const *kk = (unsigned char const *) (_key_) - 1; \
  70   while (*++kk) \
  71     (_result_) += (*kk << (kk[1] & 0xf)); \
  72 } while (0)
  73 #define return_STRING_HASH_1(_key_) do { \
  74   unsigned long result = 0; \
  75   STRING_HASH_1 ((_key_), result); \
  76   return result; \
  77 } while (0)
  78
  79 #define STRING_HASH_2(_key_, _result_) do { \
  80   unsigned char const *kk = (unsigned char const *) (_key_) - 1; \
  81   while (*++kk) \
  82     (_result_) += (*kk << (kk[1] & 0x7)); \
  83 } while (0)
  84 #define return_STRING_HASH_2(_key_) do { \
  85   unsigned long result = 0; \
  86   STRING_HASH_2 ((_key_), result); \
  87   return result; \
  88 } while (0)
  89
  90 #define STRING_COMPARE(_x_, _y_, _result_) do { \
  91   unsigned char const *xx = (unsigned char const *) (_x_) - 1; \
  92   unsigned char const *yy = (unsigned char const *) (_y_) - 1; \
  93   do { \
  94     if (*++xx == '\0') { \
  95       yy++; \
  96       break; \
  97     } \
  98   } while (*xx == *++yy); \
  99   (_result_) = *xx - *yy; \
 100 } while (0)
 101 #define return_STRING_COMPARE(_x_, _y_) do { \
 102   int result; \
 103   STRING_COMPARE (_x_, _y_, result); \
 104   return result; \
 105 } while (0)
 106
 107 /* hash and comparison macros for integer keys. */
 108
 109 #define INTEGER_HASH_1(_key_, _result_) do { \
 110   (_result_) += ((unsigned long)(_key_)); \
 111 } while (0)
 112 #define return_INTEGER_HASH_1(_key_) do { \
 113   unsigned long result = 0; \
 114   INTEGER_HASH_1 ((_key_), result); \
 115   return result; \
 116 } while (0)
 117
 118 #define INTEGER_HASH_2(_key_, _result_) do { \
 119   (_result_) += ~((unsigned long)(_key_)); \
 120 } while (0)
 121 #define return_INTEGER_HASH_2(_key_) do { \
 122   unsigned long result = 0; \
 123   INTEGER_HASH_2 ((_key_), result); \
 124   return result; \
 125 } while (0)
 126
 127 #define INTEGER_COMPARE(_x_, _y_, _result_) do { \
 128   (_result_) = _x_ - _y_; \
 129 } while (0)
 130 #define return_INTEGER_COMPARE(_x_, _y_) do { \
 131   int result; \
 132   INTEGER_COMPARE (_x_, _y_, result); \
 133   return result; \
 134 } while (0)
 135
 136 /* hash and comparison macros for address keys. */
 137
 138 #define ADDRESS_HASH_1(_key_, _result_) INTEGER_HASH_1 (((unsigned long)(_key_)) >> 3, (_result_))
 139 #define ADDRESS_HASH_2(_key_, _result_) INTEGER_HASH_2 (((unsigned long)(_key_)) >> 3, (_result_))
 140 #define ADDRESS_COMPARE(_x_, _y_, _result_) INTEGER_COMPARE ((_x_), (_y_), (_result_))
 141 #define return_ADDRESS_HASH_1(_key_) return_INTEGER_HASH_1 (((unsigned long)(_key_)) >> 3)
 142 #define return_ADDRESS_HASH_2(_key_) return_INTEGER_HASH_2 (((unsigned long)(_key_)) >> 3)
 143 #define return_ADDRESS_COMPARE(_x_, _y_) return_INTEGER_COMPARE ((_x_), (_y_))
 144
 145 #endif /* not _hash_h_ */