1 /* hash - hashing table processing.
2 Copyright (C) 1998-1999, 2001, 2003, 2009-2010 Free Software Foundation,
4 Written by Jim Meyering <meyering@ascend.com>, 1998.
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 3 of the License, or
9 (at your option) any later version.
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.
16 You should have received a copy of the GNU General Public License
17 along with this program. If not, see <http://www.gnu.org/licenses/>. */
19 /* A generic hash table package. */
21 /* Make sure USE_OBSTACK is defined to 1 if you want the allocator to use
22 obstacks instead of malloc, and recompile `hash.c' with same setting. */
30 /* The warn_unused_result attribute appeared first in gcc-3.4.0 */
31 # ifndef __attribute__
32 # if __GNUC__ < 3 || (__GNUC__ == 3 && __GNUC_MINOR__ < 4)
33 # define __attribute__(x)
37 # ifndef ATTRIBUTE_WUR
38 # define ATTRIBUTE_WUR __attribute__ ((__warn_unused_result__))
41 typedef size_t (*Hash_hasher) (const void *, size_t);
42 typedef bool (*Hash_comparator) (const void *, const void *);
43 typedef void (*Hash_data_freer) (void *);
44 typedef bool (*Hash_processor) (void *, void *);
48 /* This structure is mainly used for `hash_initialize', see the block
49 documentation of `hash_reset_tuning' for more complete comments. */
51 float shrink_threshold; /* ratio of used buckets to trigger a shrink */
52 float shrink_factor; /* ratio of new smaller size to original size */
53 float growth_threshold; /* ratio of used buckets to trigger a growth */
54 float growth_factor; /* ratio of new bigger size to original size */
55 bool is_n_buckets; /* if CANDIDATE really means table size */
58 typedef struct hash_tuning Hash_tuning;
62 typedef struct hash_table Hash_table;
64 /* Information and lookup. */
65 size_t hash_get_n_buckets (const Hash_table *);
66 size_t hash_get_n_buckets_used (const Hash_table *);
67 size_t hash_get_n_entries (const Hash_table *);
68 size_t hash_get_max_bucket_length (const Hash_table *);
69 bool hash_table_ok (const Hash_table *);
70 void hash_print_statistics (const Hash_table *, FILE *);
71 void *hash_lookup (const Hash_table *, const void *);
74 void *hash_get_first (const Hash_table *);
75 void *hash_get_next (const Hash_table *, const void *);
76 size_t hash_get_entries (const Hash_table *, void **, size_t);
77 size_t hash_do_for_each (const Hash_table *, Hash_processor, void *);
79 /* Allocation and clean-up. */
80 size_t hash_string (const char *, size_t);
81 void hash_reset_tuning (Hash_tuning *);
82 Hash_table *hash_initialize (size_t, const Hash_tuning *,
83 Hash_hasher, Hash_comparator,
84 Hash_data_freer) ATTRIBUTE_WUR;
85 void hash_clear (Hash_table *);
86 void hash_free (Hash_table *);
88 /* Insertion and deletion. */
89 bool hash_rehash (Hash_table *, size_t) ATTRIBUTE_WUR;
90 void *hash_insert (Hash_table *, const void *) ATTRIBUTE_WUR;
91 int hash_insert0 (Hash_table *table, const void *entry,
92 const void **matched_ent);
93 void *hash_delete (Hash_table *, const void *);