1 /* $MirOS: src/gnu/usr.bin/binutils/include/hashtab.h,v 1.6 2009/02/24 20:00:59 tg Exp $ */ 2 3 /* An expandable hash tables datatype. 4 Copyright (C) 1999, 2000, 2002, 2003, 2004 Free Software Foundation, Inc. 5 Contributed by Vladimir Makarov (vmakarov@cygnus.com). 6 7 This program is free software; you can redistribute it and/or modify 8 it under the terms of the GNU General Public License as published by 9 the Free Software Foundation; either version 2 of the License, or 10 (at your option) any later version. 11 12 This program is distributed in the hope that it will be useful, 13 but WITHOUT ANY WARRANTY; without even the implied warranty of 14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 GNU General Public License for more details. 16 17 You should have received a copy of the GNU General Public License 18 along with this program; if not, write to the Free Software 19 Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA. */ 20 21 /* This package implements basic hash table functionality. It is possible 22 to search for an entry, create an entry and destroy an entry. 23 24 Elements in the table are generic pointers. 25 26 The size of the table is not fixed; if the occupancy of the table 27 grows too high the hash table will be expanded. 28 29 The abstract data implementation is based on generalized Algorithm D 30 from Knuth's book "The art of computer programming". Hash table is 31 expanded by creation of new hash table and transferring elements from 32 the old table to the new table. */ 33 34 #ifndef __HASHTAB_H__ 35 #define __HASHTAB_H__ 36 37 #ifdef __cplusplus 38 extern "C" { 39 #endif /* __cplusplus */ 40 41 #include "ansidecl.h" 42 43 #ifndef GTY 44 #define GTY(X) 45 #endif 46 47 /* The type for a hash code. */ 48 typedef unsigned int hashval_t; 49 50 /* Callback function pointer types. */ 51 52 /* Calculate hash of a table entry. */ 53 typedef hashval_t (*htab_hash) (const void *); 54 55 /* Compare a table entry with a possible entry. The entry already in 56 the table always comes first, so the second element can be of a 57 different type (but in this case htab_find and htab_find_slot 58 cannot be used; instead the variants that accept a hash value 59 must be used). */ 60 typedef int (*htab_eq) (const void *, const void *); 61 62 /* Cleanup function called whenever a live element is removed from 63 the hash table. */ 64 typedef void (*htab_del) (void *); 65 66 /* Function called by htab_traverse for each live element. The first 67 arg is the slot of the element (which can be passed to htab_clear_slot 68 if desired), the second arg is the auxiliary pointer handed to 69 htab_traverse. Return 1 to continue scan, 0 to stop. */ 70 typedef int (*htab_trav) (void **, void *); 71 72 /* Memory-allocation function, with the same functionality as calloc(). 73 Iff it returns NULL, the hash table implementation will pass an error 74 code back to the user, so if your code doesn't handle errors, 75 best if you use xcalloc instead. */ 76 typedef void *(*htab_alloc) (size_t, size_t); 77 78 /* We also need a free() routine. */ 79 typedef void (*htab_free) (void *); 80 81 /* Memory allocation and deallocation; variants which take an extra 82 argument. */ 83 typedef void *(*htab_alloc_with_arg) (void *, size_t, size_t); 84 typedef void (*htab_free_with_arg) (void *, void *); 85 86 /* This macro defines reserved value for empty table entry. */ 87 88 #define HTAB_EMPTY_ENTRY ((PTR) 0) 89 90 /* This macro defines reserved value for table entry which contained 91 a deleted element. */ 92 93 #define HTAB_DELETED_ENTRY ((PTR) 1) 94 95 /* Hash tables are of the following type. The structure 96 (implementation) of this type is not needed for using the hash 97 tables. All work with hash table should be executed only through 98 functions mentioned below. The size of this structure is subject to 99 change. */ 100 101 struct htab GTY(()) 102 { 103 /* Pointer to hash function. */ 104 htab_hash hash_f; 105 106 /* Pointer to comparison function. */ 107 htab_eq eq_f; 108 109 /* Pointer to cleanup function. */ 110 htab_del del_f; 111 112 /* Table itself. */ 113 void ** GTY ((use_param (""), length ("%h.size"))) entries; 114 115 /* Current size (in entries) of the hash table. */ 116 size_t size; 117 118 /* Current number of elements including also deleted elements. */ 119 size_t n_elements; 120 121 /* Current number of deleted elements in the table. */ 122 size_t n_deleted; 123 124 /* The following member is used for debugging. Its value is number 125 of all calls of `htab_find_slot' for the hash table. */ 126 unsigned int searches; 127 128 /* The following member is used for debugging. Its value is number 129 of collisions fixed for time of work with the hash table. */ 130 unsigned int collisions; 131 132 /* Pointers to allocate/free functions. */ 133 htab_alloc alloc_f; 134 htab_free free_f; 135 136 /* Alternate allocate/free functions, which take an extra argument. */ 137 void * GTY((skip (""))) alloc_arg; 138 htab_alloc_with_arg alloc_with_arg_f; 139 htab_free_with_arg free_with_arg_f; 140 141 /* Current size (in entries) of the hash table, as an index into the 142 table of primes. */ 143 unsigned int size_prime_index; 144 }; 145 146 typedef struct htab *htab_t; 147 148 /* An enum saying whether we insert into the hash table or not. */ 149 enum insert_option {NO_INSERT, INSERT}; 150 151 /* The prototypes of the package functions. */ 152 153 extern htab_t htab_create_alloc (size_t, htab_hash, 154 htab_eq, htab_del, 155 htab_alloc, htab_free); 156 157 extern htab_t htab_create_alloc_ex (size_t, htab_hash, 158 htab_eq, htab_del, 159 void *, htab_alloc_with_arg, 160 htab_free_with_arg); 161 162 /* Backward-compatibility functions. */ 163 extern htab_t htab_create (size_t, htab_hash, htab_eq, htab_del); 164 extern htab_t htab_try_create (size_t, htab_hash, htab_eq, htab_del); 165 166 extern void htab_set_functions_ex (htab_t, htab_hash, 167 htab_eq, htab_del, 168 void *, htab_alloc_with_arg, 169 htab_free_with_arg); 170 171 extern void htab_delete (htab_t); 172 extern void htab_empty (htab_t); 173 174 extern void * htab_find (htab_t, const void *); 175 extern void ** htab_find_slot (htab_t, const void *, enum insert_option); 176 extern void * htab_find_with_hash (htab_t, const void *, hashval_t); 177 extern void ** htab_find_slot_with_hash (htab_t, const void *, 178 hashval_t, enum insert_option); 179 extern void htab_clear_slot (htab_t, void **); 180 extern void htab_remove_elt (htab_t, void *); 181 extern void htab_remove_elt_with_hash (htab_t, void *, hashval_t); 182 183 extern void htab_traverse (htab_t, htab_trav, void *); 184 extern void htab_traverse_noresize (htab_t, htab_trav, void *); 185 186 extern size_t htab_size (htab_t); 187 extern size_t htab_elements (htab_t); 188 extern double htab_collisions (htab_t); 189 190 /* A hash function for pointers. */ 191 extern htab_hash htab_hash_pointer; 192 193 /* An equality function for pointers. */ 194 extern htab_eq htab_eq_pointer; 195 196 /* A hash function for null-terminated strings. */ 197 extern hashval_t htab_hash_string (const void *); 198 199 /* An iterative hash function for arbitrary data. */ 200 extern hashval_t iterative_hash (const void *, size_t, hashval_t); 201 /* Shorthand for hashing something with an intrinsic size. */ 202 #define iterative_hash_object(OB,INIT) iterative_hash (&OB, sizeof (OB), INIT) 203 204 #ifdef __cplusplus 205 } 206 #endif /* __cplusplus */ 207 208 #endif /* __HASHTAB_H */ 209