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501df194 | 1 | /* An expandable hash tables datatype. |
ba72912a | 2 | Copyright (C) 1999, 2000, 2002, 2003, 2004, 2005, 2009, 2010 |
ff68eb44 | 3 | Free Software Foundation, Inc. |
501df194 | 4 | Contributed by Vladimir Makarov (vmakarov@cygnus.com). |
5 | ||
6 | This program is free software; you can redistribute it and/or modify | |
7 | it under the terms of the GNU General Public License as published by | |
8 | the Free Software Foundation; either version 2 of the License, or | |
9 | (at your option) any later version. | |
10 | ||
11 | This program is distributed in the hope that it will be useful, | |
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | GNU General Public License for more details. | |
15 | ||
16 | You should have received a copy of the GNU General Public License | |
17 | along with this program; if not, write to the Free Software | |
2f8ebb8e | 18 | Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA. */ |
501df194 | 19 | |
20 | /* This package implements basic hash table functionality. It is possible | |
21 | to search for an entry, create an entry and destroy an entry. | |
22 | ||
23 | Elements in the table are generic pointers. | |
24 | ||
25 | The size of the table is not fixed; if the occupancy of the table | |
26 | grows too high the hash table will be expanded. | |
27 | ||
28 | The abstract data implementation is based on generalized Algorithm D | |
29 | from Knuth's book "The art of computer programming". Hash table is | |
30 | expanded by creation of new hash table and transferring elements from | |
31 | the old table to the new table. */ | |
32 | ||
33 | #ifndef __HASHTAB_H__ | |
34 | #define __HASHTAB_H__ | |
35 | ||
36 | #ifdef __cplusplus | |
37 | extern "C" { | |
38 | #endif /* __cplusplus */ | |
39 | ||
5f94337d | 40 | #include "ansidecl.h" |
501df194 | 41 | |
1f3233d1 | 42 | #ifndef GTY |
43 | #define GTY(X) | |
44 | #endif | |
45 | ||
7669680f | 46 | /* The type for a hash code. */ |
47 | typedef unsigned int hashval_t; | |
48 | ||
07c967f9 | 49 | /* Callback function pointer types. */ |
501df194 | 50 | |
07c967f9 | 51 | /* Calculate hash of a table entry. */ |
8858115e | 52 | typedef hashval_t (*htab_hash) (const void *); |
07c967f9 | 53 | |
54 | /* Compare a table entry with a possible entry. The entry already in | |
ed26da85 | 55 | the table always comes first, so the second element can be of a |
56 | different type (but in this case htab_find and htab_find_slot | |
57 | cannot be used; instead the variants that accept a hash value | |
58 | must be used). */ | |
8858115e | 59 | typedef int (*htab_eq) (const void *, const void *); |
07c967f9 | 60 | |
3fdd387a | 61 | /* Cleanup function called whenever a live element is removed from |
62 | the hash table. */ | |
8858115e | 63 | typedef void (*htab_del) (void *); |
3fdd387a | 64 | |
07c967f9 | 65 | /* Function called by htab_traverse for each live element. The first |
ed26da85 | 66 | arg is the slot of the element (which can be passed to htab_clear_slot |
67 | if desired), the second arg is the auxiliary pointer handed to | |
68 | htab_traverse. Return 1 to continue scan, 0 to stop. */ | |
8858115e | 69 | typedef int (*htab_trav) (void **, void *); |
501df194 | 70 | |
1f3233d1 | 71 | /* Memory-allocation function, with the same functionality as calloc(). |
72 | Iff it returns NULL, the hash table implementation will pass an error | |
73 | code back to the user, so if your code doesn't handle errors, | |
74 | best if you use xcalloc instead. */ | |
2b0988cf | 75 | typedef void *(*htab_alloc) (size_t, size_t); |
1f3233d1 | 76 | |
77 | /* We also need a free() routine. */ | |
2b0988cf | 78 | typedef void (*htab_free) (void *); |
1f3233d1 | 79 | |
a21acbbb | 80 | /* Memory allocation and deallocation; variants which take an extra |
81 | argument. */ | |
2b0988cf | 82 | typedef void *(*htab_alloc_with_arg) (void *, size_t, size_t); |
8858115e | 83 | typedef void (*htab_free_with_arg) (void *, void *); |
a21acbbb | 84 | |
a55dc2cd | 85 | /* This macro defines reserved value for empty table entry. */ |
86 | ||
87 | #define HTAB_EMPTY_ENTRY ((PTR) 0) | |
88 | ||
89 | /* This macro defines reserved value for table entry which contained | |
90 | a deleted element. */ | |
91 | ||
92 | #define HTAB_DELETED_ENTRY ((PTR) 1) | |
93 | ||
501df194 | 94 | /* Hash tables are of the following type. The structure |
95 | (implementation) of this type is not needed for using the hash | |
96 | tables. All work with hash table should be executed only through | |
a21acbbb | 97 | functions mentioned below. The size of this structure is subject to |
98 | change. */ | |
501df194 | 99 | |
fb1e4f4a | 100 | struct GTY(()) htab { |
07c967f9 | 101 | /* Pointer to hash function. */ |
102 | htab_hash hash_f; | |
103 | ||
3fdd387a | 104 | /* Pointer to comparison function. */ |
07c967f9 | 105 | htab_eq eq_f; |
106 | ||
3fdd387a | 107 | /* Pointer to cleanup function. */ |
108 | htab_del del_f; | |
109 | ||
110 | /* Table itself. */ | |
2b0988cf | 111 | void ** GTY ((use_param, length ("%h.size"))) entries; |
07c967f9 | 112 | |
e3190d3d | 113 | /* Current size (in entries) of the hash table. */ |
501df194 | 114 | size_t size; |
07c967f9 | 115 | |
e3190d3d | 116 | /* Current number of elements including also deleted elements. */ |
07c967f9 | 117 | size_t n_elements; |
118 | ||
e3190d3d | 119 | /* Current number of deleted elements in the table. */ |
07c967f9 | 120 | size_t n_deleted; |
121 | ||
501df194 | 122 | /* The following member is used for debugging. Its value is number |
07c967f9 | 123 | of all calls of `htab_find_slot' for the hash table. */ |
124 | unsigned int searches; | |
125 | ||
501df194 | 126 | /* The following member is used for debugging. Its value is number |
127 | of collisions fixed for time of work with the hash table. */ | |
07c967f9 | 128 | unsigned int collisions; |
1a48bdeb | 129 | |
130 | /* Pointers to allocate/free functions. */ | |
131 | htab_alloc alloc_f; | |
132 | htab_free free_f; | |
a21acbbb | 133 | |
134 | /* Alternate allocate/free functions, which take an extra argument. */ | |
2b0988cf | 135 | void * GTY((skip)) alloc_arg; |
a21acbbb | 136 | htab_alloc_with_arg alloc_with_arg_f; |
137 | htab_free_with_arg free_with_arg_f; | |
e3190d3d | 138 | |
139 | /* Current size (in entries) of the hash table, as an index into the | |
140 | table of primes. */ | |
141 | unsigned int size_prime_index; | |
07c967f9 | 142 | }; |
501df194 | 143 | |
07c967f9 | 144 | typedef struct htab *htab_t; |
501df194 | 145 | |
2b3dbc20 | 146 | /* An enum saying whether we insert into the hash table or not. */ |
147 | enum insert_option {NO_INSERT, INSERT}; | |
148 | ||
501df194 | 149 | /* The prototypes of the package functions. */ |
150 | ||
8858115e | 151 | extern htab_t htab_create_alloc (size_t, htab_hash, |
152 | htab_eq, htab_del, | |
153 | htab_alloc, htab_free); | |
1f3233d1 | 154 | |
8858115e | 155 | extern htab_t htab_create_alloc_ex (size_t, htab_hash, |
156 | htab_eq, htab_del, | |
2b0988cf | 157 | void *, htab_alloc_with_arg, |
8858115e | 158 | htab_free_with_arg); |
a21acbbb | 159 | |
ba72912a | 160 | extern htab_t htab_create_typed_alloc (size_t, htab_hash, htab_eq, htab_del, |
161 | htab_alloc, htab_alloc, htab_free); | |
162 | ||
8d24e548 | 163 | /* Backward-compatibility functions. */ |
8858115e | 164 | extern htab_t htab_create (size_t, htab_hash, htab_eq, htab_del); |
165 | extern htab_t htab_try_create (size_t, htab_hash, htab_eq, htab_del); | |
166 | ||
167 | extern void htab_set_functions_ex (htab_t, htab_hash, | |
168 | htab_eq, htab_del, | |
2b0988cf | 169 | void *, htab_alloc_with_arg, |
8858115e | 170 | htab_free_with_arg); |
171 | ||
172 | extern void htab_delete (htab_t); | |
173 | extern void htab_empty (htab_t); | |
174 | ||
2b0988cf | 175 | extern void * htab_find (htab_t, const void *); |
176 | extern void ** htab_find_slot (htab_t, const void *, enum insert_option); | |
177 | extern void * htab_find_with_hash (htab_t, const void *, hashval_t); | |
178 | extern void ** htab_find_slot_with_hash (htab_t, const void *, | |
179 | hashval_t, enum insert_option); | |
8858115e | 180 | extern void htab_clear_slot (htab_t, void **); |
181 | extern void htab_remove_elt (htab_t, void *); | |
182 | extern void htab_remove_elt_with_hash (htab_t, void *, hashval_t); | |
183 | ||
184 | extern void htab_traverse (htab_t, htab_trav, void *); | |
185 | extern void htab_traverse_noresize (htab_t, htab_trav, void *); | |
186 | ||
187 | extern size_t htab_size (htab_t); | |
188 | extern size_t htab_elements (htab_t); | |
189 | extern double htab_collisions (htab_t); | |
501df194 | 190 | |
c9dfb8ae | 191 | /* A hash function for pointers. */ |
192 | extern htab_hash htab_hash_pointer; | |
193 | ||
194 | /* An equality function for pointers. */ | |
195 | extern htab_eq htab_eq_pointer; | |
196 | ||
25fecab7 | 197 | /* A hash function for null-terminated strings. */ |
2b0988cf | 198 | extern hashval_t htab_hash_string (const void *); |
25fecab7 | 199 | |
b3552be1 | 200 | /* An iterative hash function for arbitrary data. */ |
2b0988cf | 201 | extern hashval_t iterative_hash (const void *, size_t, hashval_t); |
b3552be1 | 202 | /* Shorthand for hashing something with an intrinsic size. */ |
24bfa234 | 203 | #define iterative_hash_object(OB,INIT) iterative_hash (&OB, sizeof (OB), INIT) |
b3552be1 | 204 | |
501df194 | 205 | #ifdef __cplusplus |
206 | } | |
207 | #endif /* __cplusplus */ | |
208 | ||
209 | #endif /* __HASHTAB_H */ |