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 #if defined (__GNUC__) || (defined (__STDC__) && __STDC__)
  25 #define __P(args) args
  26 #else
  27 #define __P(args) ()
  28 #endif  /* GCC.  */
  29
  30 typedef unsigned long (*hash_func_t) __P((void const *key));
  31 typedef int (*hash_cmp_func_t) __P((void const *x, void const *y));
  32 typedef void (*hash_map_func_t) __P((void const *item));
  33
  34 struct hash_table
  35 {
  36   void **ht_vec;
  37   unsigned long ht_size;        /* total number of slots (power of 2) */
  38   unsigned long ht_capacity;    /* usable slots, limited by loading-factor */
  39   unsigned long ht_fill;        /* items in table */
  40   unsigned long ht_collisions;  /* # of failed calls to comparison function */
  41   unsigned long ht_lookups;     /* # of queries */
  42   unsigned int ht_rehashes;     /* # of times we've expanded table */
  43   hash_func_t ht_hash_1;        /* primary hash function */
  44   hash_func_t ht_hash_2;        /* secondary hash function */
  45   hash_cmp_func_t ht_compare;   /* comparison function */
  46 };
  47
  48 typedef int (*qsort_cmp_t) __P((void const *, void const *));
  49
  50 void hash_init __P((struct hash_table *ht, unsigned long size,
  51                     hash_func_t hash_1, hash_func_t hash_2, hash_cmp_func_t hash_cmp));
  52 void hash_load __P((struct hash_table *ht, void *item_table,
  53                     unsigned long cardinality, unsigned long size));
  54 void **hash_find_slot __P((struct hash_table *ht, void const *key));
  55 void *hash_find_item __P((struct hash_table *ht, void const *key));
  56 const void *hash_insert __P((struct hash_table *ht, void *item));
  57 const void *hash_insert_at __P((struct hash_table *ht, void *item, void const *slot));
  58 const void *hash_delete __P((struct hash_table *ht, void const *item));
  59 const void *hash_delete_at __P((struct hash_table *ht, void const *slot));
  60 void hash_delete_items __P((struct hash_table *ht));
  61 void hash_free_items __P((struct hash_table *ht));
  62 void hash_free __P((struct hash_table *ht, int free_items));
  63 void hash_map __P((struct hash_table *ht, hash_map_func_t map));
  64 void hash_print_stats __P((struct hash_table *ht, FILE *out_FILE));
  65 void **hash_dump __P((struct hash_table *ht, void **vector_0, qsort_cmp_t compare));
  66
  67 extern void *hash_deleted_item;
  68 #define HASH_VACANT(item) \
  69    ((item) == 0 || (const void *) (item) == hash_deleted_item)
  70
  71 \f
  72 /* hash and comparison macros for string keys. */
  73
  74 #define STRING_HASH_1(_key_, _result_) { \
  75   unsigned char const *kk = (unsigned char const *) (_key_) - 1; \
  76   while (*++kk) \
  77     (_result_) += (*kk << (kk[1] & 0xf)); \
  78 } while (0)
  79 #define return_STRING_HASH_1(_key_) do { \
  80   unsigned long result = 0; \
  81   STRING_HASH_1 ((_key_), result); \
  82   return result; \
  83 } while (0)
  84
  85 #define STRING_HASH_2(_key_, _result_) do { \
  86   unsigned char const *kk = (unsigned char const *) (_key_) - 1; \
  87   while (*++kk) \
  88     (_result_) += (*kk << (kk[1] & 0x7)); \
  89 } while (0)
  90 #define return_STRING_HASH_2(_key_) do { \
  91   unsigned long result = 0; \
  92   STRING_HASH_2 ((_key_), result); \
  93   return result; \
  94 } while (0)
  95
  96 #define STRING_COMPARE(_x_, _y_, _result_) do { \
  97   unsigned char const *xx = (unsigned char const *) (_x_) - 1; \
  98   unsigned char const *yy = (unsigned char const *) (_y_) - 1; \
  99   do { \
 100     if (*++xx == '\0') { \
 101       yy++; \
 102       break; \
 103     } \
 104   } while (*xx == *++yy); \
 105   (_result_) = *xx - *yy; \
 106 } while (0)
 107 #define return_STRING_COMPARE(_x_, _y_) do { \
 108   int result; \
 109   STRING_COMPARE (_x_, _y_, result); \
 110   return result; \
 111 } while (0)
 112
 113 /* hash and comparison macros for integer keys. */
 114
 115 #define INTEGER_HASH_1(_key_, _result_) do { \
 116   (_result_) += ((unsigned long)(_key_)); \
 117 } while (0)
 118 #define return_INTEGER_HASH_1(_key_) do { \
 119   unsigned long result = 0; \
 120   INTEGER_HASH_1 ((_key_), result); \
 121   return result; \
 122 } while (0)
 123
 124 #define INTEGER_HASH_2(_key_, _result_) do { \
 125   (_result_) += ~((unsigned long)(_key_)); \
 126 } while (0)
 127 #define return_INTEGER_HASH_2(_key_) do { \
 128   unsigned long result = 0; \
 129   INTEGER_HASH_2 ((_key_), result); \
 130   return result; \
 131 } while (0)
 132
 133 #define INTEGER_COMPARE(_x_, _y_, _result_) do { \
 134   (_result_) = _x_ - _y_; \
 135 } while (0)
 136 #define return_INTEGER_COMPARE(_x_, _y_) do { \
 137   int result; \
 138   INTEGER_COMPARE (_x_, _y_, result); \
 139   return result; \
 140 } while (0)
 141
 142 /* hash and comparison macros for address keys. */
 143
 144 #define ADDRESS_HASH_1(_key_, _result_) INTEGER_HASH_1 (((unsigned long)(_key_)) >> 3, (_result_))
 145 #define ADDRESS_HASH_2(_key_, _result_) INTEGER_HASH_2 (((unsigned long)(_key_)) >> 3, (_result_))
 146 #define ADDRESS_COMPARE(_x_, _y_, _result_) INTEGER_COMPARE ((_x_), (_y_), (_result_))
 147 #define return_ADDRESS_HASH_1(_key_) return_INTEGER_HASH_1 (((unsigned long)(_key_)) >> 3)
 148 #define return_ADDRESS_HASH_2(_key_) return_INTEGER_HASH_2 (((unsigned long)(_key_)) >> 3)
 149 #define return_ADDRESS_COMPARE(_x_, _y_) return_INTEGER_COMPARE ((_x_), (_y_))
 150
 151 #endif /* not _hash_h_ */