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 #ifndef PARAMS
  25 # if defined PROTOTYPES || defined __STDC__
  26 #  define PARAMS(Args) Args
  27 # else
  28 #  define PARAMS(Args) ()
  29 # endif
  30 #endif
  31
  32 typedef unsigned long (*hash_func_t) PARAMS((void const *key));
  33 typedef int (*hash_cmp_func_t) PARAMS((void const *x, void const *y));
  34 typedef void (*hash_map_func_t) PARAMS((void const *item));
  35
  36 struct hash_table
  37 {
  38   void **ht_vec;
  39   unsigned long ht_size;        /* total number of slots (power of 2) */
  40   unsigned long ht_capacity;    /* usable slots, limited by loading-factor */
  41   unsigned long ht_fill;        /* items in table */
  42   unsigned long ht_collisions;  /* # of failed calls to comparison function */
  43   unsigned long ht_lookups;     /* # of queries */
  44   unsigned int ht_rehashes;     /* # of times we've expanded table */
  45   hash_func_t ht_hash_1;        /* primary hash function */
  46   hash_func_t ht_hash_2;        /* secondary hash function */
  47   hash_cmp_func_t ht_compare;   /* comparison function */
  48 };
  49
  50 typedef int (*qsort_cmp_t) PARAMS((void const *, void const *));
  51
  52 void hash_init PARAMS((struct hash_table *ht, unsigned long size,
  53                        hash_func_t hash_1, hash_func_t hash_2, hash_cmp_func_t hash_cmp));
  54 void hash_load PARAMS((struct hash_table *ht, void *item_table,
  55                        unsigned long cardinality, unsigned long size));
  56 void **hash_find_slot PARAMS((struct hash_table *ht, void const *key));
  57 void *hash_find_item PARAMS((struct hash_table *ht, void const *key));
  58 const void *hash_insert PARAMS((struct hash_table *ht, void *item));
  59 const void *hash_insert_at PARAMS((struct hash_table *ht, void *item, void const *slot));
  60 const void *hash_delete PARAMS((struct hash_table *ht, void const *item));
  61 const void *hash_delete_at PARAMS((struct hash_table *ht, void const *slot));
  62 void hash_delete_items PARAMS((struct hash_table *ht));
  63 void hash_free_items PARAMS((struct hash_table *ht));
  64 void hash_free PARAMS((struct hash_table *ht, int free_items));
  65 void hash_map PARAMS((struct hash_table *ht, hash_map_func_t map));
  66 void hash_print_stats PARAMS((struct hash_table *ht, FILE *out_FILE));
  67 void **hash_dump PARAMS((struct hash_table *ht, void **vector_0, qsort_cmp_t compare));
  68
  69 extern void *hash_deleted_item;
  70 #define HASH_VACANT(item) \
  71    ((item) == 0 || (const void *) (item) == hash_deleted_item)
  72
  73 \f
  74 /* hash and comparison macros for string keys. */
  75
  76 #define STRING_HASH_1(_key_, _result_) { \
  77   unsigned char const *kk = (unsigned char const *) (_key_) - 1; \
  78   while (*++kk) \
  79     (_result_) += (*kk << (kk[1] & 0xf)); \
  80 } while (0)
  81 #define return_STRING_HASH_1(_key_) do { \
  82   unsigned long result = 0; \
  83   STRING_HASH_1 ((_key_), result); \
  84   return result; \
  85 } while (0)
  86
  87 #define STRING_HASH_2(_key_, _result_) do { \
  88   unsigned char const *kk = (unsigned char const *) (_key_) - 1; \
  89   while (*++kk) \
  90     (_result_) += (*kk << (kk[1] & 0x7)); \
  91 } while (0)
  92 #define return_STRING_HASH_2(_key_) do { \
  93   unsigned long result = 0; \
  94   STRING_HASH_2 ((_key_), result); \
  95   return result; \
  96 } while (0)
  97
  98 #define STRING_COMPARE(_x_, _y_, _result_) do { \
  99   unsigned char const *xx = (unsigned char const *) (_x_) - 1; \
 100   unsigned char const *yy = (unsigned char const *) (_y_) - 1; \
 101   do { \
 102     if (*++xx == '\0') { \
 103       yy++; \
 104       break; \
 105     } \
 106   } while (*xx == *++yy); \
 107   (_result_) = *xx - *yy; \
 108 } while (0)
 109 #define return_STRING_COMPARE(_x_, _y_) do { \
 110   int result; \
 111   STRING_COMPARE (_x_, _y_, result); \
 112   return result; \
 113 } while (0)
 114
 115 /* hash and comparison macros for integer keys. */
 116
 117 #define INTEGER_HASH_1(_key_, _result_) do { \
 118   (_result_) += ((unsigned long)(_key_)); \
 119 } while (0)
 120 #define return_INTEGER_HASH_1(_key_) do { \
 121   unsigned long result = 0; \
 122   INTEGER_HASH_1 ((_key_), result); \
 123   return result; \
 124 } while (0)
 125
 126 #define INTEGER_HASH_2(_key_, _result_) do { \
 127   (_result_) += ~((unsigned long)(_key_)); \
 128 } while (0)
 129 #define return_INTEGER_HASH_2(_key_) do { \
 130   unsigned long result = 0; \
 131   INTEGER_HASH_2 ((_key_), result); \
 132   return result; \
 133 } while (0)
 134
 135 #define INTEGER_COMPARE(_x_, _y_, _result_) do { \
 136   (_result_) = _x_ - _y_; \
 137 } while (0)
 138 #define return_INTEGER_COMPARE(_x_, _y_) do { \
 139   int result; \
 140   INTEGER_COMPARE (_x_, _y_, result); \
 141   return result; \
 142 } while (0)
 143
 144 /* hash and comparison macros for address keys. */
 145
 146 #define ADDRESS_HASH_1(_key_, _result_) INTEGER_HASH_1 (((unsigned long)(_key_)) >> 3, (_result_))
 147 #define ADDRESS_HASH_2(_key_, _result_) INTEGER_HASH_2 (((unsigned long)(_key_)) >> 3, (_result_))
 148 #define ADDRESS_COMPARE(_x_, _y_, _result_) INTEGER_COMPARE ((_x_), (_y_), (_result_))
 149 #define return_ADDRESS_HASH_1(_key_) return_INTEGER_HASH_1 (((unsigned long)(_key_)) >> 3)
 150 #define return_ADDRESS_HASH_2(_key_) return_INTEGER_HASH_2 (((unsigned long)(_key_)) >> 3)
 151 #define return_ADDRESS_COMPARE(_x_, _y_) return_INTEGER_COMPARE ((_x_), (_y_))
 152
 153 #endif /* not _hash_h_ */