1 /* hash - hashing table processing.
2 Copyright (C) 1998, 1999, 2001, 2003, 2009 Free Software Foundation, Inc.
3 Written by Jim Meyering <meyering@ascend.com>, 1998.
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 3 of the License, or
8 (at your option) any later version.
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.
15 You should have received a copy of the GNU General Public License
16 along with this program. If not, see <http://www.gnu.org/licenses/>. */
18 /* A generic hash table package. */
20 /* Make sure USE_OBSTACK is defined to 1 if you want the allocator to use
21 obstacks instead of malloc, and recompile `hash.c' with same setting. */
29 /* The warn_unused_result attribute appeared first in gcc-3.4.0 */
30 # ifndef __attribute__
31 # if __GNUC__ < 3 || (__GNUC__ == 3 && __GNUC_MINOR__ < 4)
32 # define __attribute__(x)
36 # ifndef ATTRIBUTE_WUR
37 # define ATTRIBUTE_WUR __attribute__ ((__warn_unused_result__))
40 typedef size_t (*Hash_hasher) (const void *, size_t);
41 typedef bool (*Hash_comparator) (const void *, const void *);
42 typedef void (*Hash_data_freer) (void *);
43 typedef bool (*Hash_processor) (void *, void *);
48 struct hash_entry *next;
53 /* This structure is mainly used for `hash_initialize', see the block
54 documentation of `hash_reset_tuning' for more complete comments. */
56 float shrink_threshold; /* ratio of used buckets to trigger a shrink */
57 float shrink_factor; /* ratio of new smaller size to original size */
58 float growth_threshold; /* ratio of used buckets to trigger a growth */
59 float growth_factor; /* ratio of new bigger size to original size */
60 bool is_n_buckets; /* if CANDIDATE really means table size */
63 typedef struct hash_tuning Hash_tuning;
67 typedef struct hash_table Hash_table;
69 /* Information and lookup. */
70 size_t hash_get_n_buckets (const Hash_table *);
71 size_t hash_get_n_buckets_used (const Hash_table *);
72 size_t hash_get_n_entries (const Hash_table *);
73 size_t hash_get_max_bucket_length (const Hash_table *);
74 bool hash_table_ok (const Hash_table *);
75 void hash_print_statistics (const Hash_table *, FILE *);
76 void *hash_lookup (const Hash_table *, const void *);
79 void *hash_get_first (const Hash_table *);
80 void *hash_get_next (const Hash_table *, const void *);
81 size_t hash_get_entries (const Hash_table *, void **, size_t);
82 size_t hash_do_for_each (const Hash_table *, Hash_processor, void *);
84 /* Allocation and clean-up. */
85 size_t hash_string (const char *, size_t);
86 void hash_reset_tuning (Hash_tuning *);
87 Hash_table *hash_initialize (size_t, const Hash_tuning *,
88 Hash_hasher, Hash_comparator,
89 Hash_data_freer) ATTRIBUTE_WUR;
90 void hash_clear (Hash_table *);
91 void hash_free (Hash_table *);
93 /* Insertion and deletion. */
94 bool hash_rehash (Hash_table *, size_t) ATTRIBUTE_WUR;
95 void *hash_insert (Hash_table *, const void *) ATTRIBUTE_WUR;
96 void *hash_delete (Hash_table *, const void *);