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a6ee63bb | 1 | /* An expandable hash tables datatype. |
74828682 | 2 | Copyright (C) 1999, 2000, 2002, 2003 Free Software Foundation, Inc. |
a6ee63bb VM |
3 | Contributed by Vladimir Makarov (vmakarov@cygnus.com). |
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 of the License, or | |
8 | (at your option) 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 | /* This package implements basic hash table functionality. It is possible | |
20 | to search for an entry, create an entry and destroy an entry. | |
21 | ||
22 | Elements in the table are generic pointers. | |
23 | ||
24 | The size of the table is not fixed; if the occupancy of the table | |
25 | grows too high the hash table will be expanded. | |
26 | ||
27 | The abstract data implementation is based on generalized Algorithm D | |
28 | from Knuth's book "The art of computer programming". Hash table is | |
29 | expanded by creation of new hash table and transferring elements from | |
30 | the old table to the new table. */ | |
31 | ||
32 | #ifndef __HASHTAB_H__ | |
33 | #define __HASHTAB_H__ | |
34 | ||
35 | #ifdef __cplusplus | |
36 | extern "C" { | |
37 | #endif /* __cplusplus */ | |
38 | ||
8ff82b06 | 39 | #include "ansidecl.h" |
a6ee63bb | 40 | |
e2500fed GK |
41 | #ifndef GTY |
42 | #define GTY(X) | |
43 | #endif | |
44 | ||
b13eb66b MM |
45 | /* The type for a hash code. */ |
46 | typedef unsigned int hashval_t; | |
47 | ||
5194cf08 | 48 | /* Callback function pointer types. */ |
a6ee63bb | 49 | |
5194cf08 | 50 | /* Calculate hash of a table entry. */ |
b13eb66b | 51 | typedef hashval_t (*htab_hash) PARAMS ((const void *)); |
5194cf08 ZW |
52 | |
53 | /* Compare a table entry with a possible entry. The entry already in | |
8c5d513f BS |
54 | the table always comes first, so the second element can be of a |
55 | different type (but in this case htab_find and htab_find_slot | |
56 | cannot be used; instead the variants that accept a hash value | |
57 | must be used). */ | |
5194cf08 ZW |
58 | typedef int (*htab_eq) PARAMS ((const void *, const void *)); |
59 | ||
5dc9cffd ZW |
60 | /* Cleanup function called whenever a live element is removed from |
61 | the hash table. */ | |
62 | typedef void (*htab_del) PARAMS ((void *)); | |
63 | ||
5194cf08 | 64 | /* Function called by htab_traverse for each live element. The first |
8c5d513f BS |
65 | arg is the slot of the element (which can be passed to htab_clear_slot |
66 | if desired), the second arg is the auxiliary pointer handed to | |
67 | htab_traverse. Return 1 to continue scan, 0 to stop. */ | |
68 | typedef int (*htab_trav) PARAMS ((void **, void *)); | |
a6ee63bb | 69 | |
e2500fed GK |
70 | /* Memory-allocation function, with the same functionality as calloc(). |
71 | Iff it returns NULL, the hash table implementation will pass an error | |
72 | code back to the user, so if your code doesn't handle errors, | |
73 | best if you use xcalloc instead. */ | |
74 | typedef PTR (*htab_alloc) PARAMS ((size_t, size_t)); | |
75 | ||
76 | /* We also need a free() routine. */ | |
77 | typedef void (*htab_free) PARAMS ((PTR)); | |
78 | ||
74828682 DJ |
79 | /* Memory allocation and deallocation; variants which take an extra |
80 | argument. */ | |
81 | typedef PTR (*htab_alloc_with_arg) PARAMS ((void *, size_t, size_t)); | |
82 | typedef void (*htab_free_with_arg) PARAMS ((void *, void *)); | |
83 | ||
a6ee63bb VM |
84 | /* Hash tables are of the following type. The structure |
85 | (implementation) of this type is not needed for using the hash | |
86 | tables. All work with hash table should be executed only through | |
74828682 DJ |
87 | functions mentioned below. The size of this structure is subject to |
88 | change. */ | |
a6ee63bb | 89 | |
e2500fed | 90 | struct htab GTY(()) |
a6ee63bb | 91 | { |
5194cf08 ZW |
92 | /* Pointer to hash function. */ |
93 | htab_hash hash_f; | |
94 | ||
5dc9cffd | 95 | /* Pointer to comparison function. */ |
5194cf08 ZW |
96 | htab_eq eq_f; |
97 | ||
5dc9cffd ZW |
98 | /* Pointer to cleanup function. */ |
99 | htab_del del_f; | |
100 | ||
101 | /* Table itself. */ | |
e2500fed | 102 | PTR * GTY ((use_param (""), length ("%h.size"))) entries; |
5194cf08 | 103 | |
a6ee63bb VM |
104 | /* Current size (in entries) of the hash table */ |
105 | size_t size; | |
5194cf08 | 106 | |
a6ee63bb | 107 | /* Current number of elements including also deleted elements */ |
5194cf08 ZW |
108 | size_t n_elements; |
109 | ||
a6ee63bb | 110 | /* Current number of deleted elements in the table */ |
5194cf08 ZW |
111 | size_t n_deleted; |
112 | ||
a6ee63bb | 113 | /* The following member is used for debugging. Its value is number |
5194cf08 ZW |
114 | of all calls of `htab_find_slot' for the hash table. */ |
115 | unsigned int searches; | |
116 | ||
a6ee63bb VM |
117 | /* The following member is used for debugging. Its value is number |
118 | of collisions fixed for time of work with the hash table. */ | |
5194cf08 | 119 | unsigned int collisions; |
917ccc05 DD |
120 | |
121 | /* Pointers to allocate/free functions. */ | |
122 | htab_alloc alloc_f; | |
123 | htab_free free_f; | |
74828682 DJ |
124 | |
125 | /* Alternate allocate/free functions, which take an extra argument. */ | |
126 | PTR GTY((skip (""))) alloc_arg; | |
127 | htab_alloc_with_arg alloc_with_arg_f; | |
128 | htab_free_with_arg free_with_arg_f; | |
5194cf08 | 129 | }; |
a6ee63bb | 130 | |
5194cf08 | 131 | typedef struct htab *htab_t; |
a6ee63bb | 132 | |
e38992e8 RK |
133 | /* An enum saying whether we insert into the hash table or not. */ |
134 | enum insert_option {NO_INSERT, INSERT}; | |
135 | ||
a6ee63bb VM |
136 | /* The prototypes of the package functions. */ |
137 | ||
e2500fed GK |
138 | extern htab_t htab_create_alloc PARAMS ((size_t, htab_hash, |
139 | htab_eq, htab_del, | |
140 | htab_alloc, htab_free)); | |
141 | ||
74828682 DJ |
142 | extern htab_t htab_create_alloc_ex PARAMS ((size_t, htab_hash, |
143 | htab_eq, htab_del, | |
144 | PTR, htab_alloc_with_arg, | |
145 | htab_free_with_arg)); | |
146 | ||
045b3a49 GK |
147 | /* Backward-compatibility functions. */ |
148 | extern htab_t htab_create PARAMS ((size_t, htab_hash, htab_eq, htab_del)); | |
149 | extern htab_t htab_try_create PARAMS ((size_t, htab_hash, htab_eq, htab_del)); | |
150 | ||
74828682 DJ |
151 | extern void htab_set_functions_ex PARAMS ((htab_t, htab_hash, |
152 | htab_eq, htab_del, | |
153 | PTR, htab_alloc_with_arg, | |
154 | htab_free_with_arg)); | |
155 | ||
5194cf08 ZW |
156 | extern void htab_delete PARAMS ((htab_t)); |
157 | extern void htab_empty PARAMS ((htab_t)); | |
a6ee63bb | 158 | |
5aa23000 HPN |
159 | extern PTR htab_find PARAMS ((htab_t, const void *)); |
160 | extern PTR *htab_find_slot PARAMS ((htab_t, const void *, | |
e38992e8 | 161 | enum insert_option)); |
5aa23000 | 162 | extern PTR htab_find_with_hash PARAMS ((htab_t, const void *, |
e38992e8 | 163 | hashval_t)); |
5aa23000 | 164 | extern PTR *htab_find_slot_with_hash PARAMS ((htab_t, const void *, |
e38992e8 RK |
165 | hashval_t, |
166 | enum insert_option)); | |
5194cf08 ZW |
167 | extern void htab_clear_slot PARAMS ((htab_t, void **)); |
168 | extern void htab_remove_elt PARAMS ((htab_t, void *)); | |
a6ee63bb | 169 | |
5194cf08 | 170 | extern void htab_traverse PARAMS ((htab_t, htab_trav, void *)); |
dbccdc42 | 171 | extern void htab_traverse_noresize PARAMS ((htab_t, htab_trav, void *)); |
a6ee63bb | 172 | |
5194cf08 ZW |
173 | extern size_t htab_size PARAMS ((htab_t)); |
174 | extern size_t htab_elements PARAMS ((htab_t)); | |
175 | extern double htab_collisions PARAMS ((htab_t)); | |
a6ee63bb | 176 | |
18a94a2f MM |
177 | /* A hash function for pointers. */ |
178 | extern htab_hash htab_hash_pointer; | |
179 | ||
180 | /* An equality function for pointers. */ | |
181 | extern htab_eq htab_eq_pointer; | |
182 | ||
457f49df RH |
183 | /* A hash function for null-terminated strings. */ |
184 | extern hashval_t htab_hash_string PARAMS ((const PTR)); | |
185 | ||
5cc5a0d0 | 186 | /* An iterative hash function for arbitrary data. */ |
9d70d418 | 187 | extern hashval_t iterative_hash PARAMS ((const PTR, size_t, hashval_t)); |
5cc5a0d0 | 188 | /* Shorthand for hashing something with an intrinsic size. */ |
9d70d418 | 189 | #define iterative_hash_object(OB,INIT) iterative_hash (&OB, sizeof (OB), INIT) |
5cc5a0d0 | 190 | |
a6ee63bb VM |
191 | #ifdef __cplusplus |
192 | } | |
193 | #endif /* __cplusplus */ | |
194 | ||
195 | #endif /* __HASHTAB_H */ |