1 /* hash - hashing table processing. 2 Copyright (C) 1998-1999, 2001, 2003, 2009-2011 Free Software Foundation, 3 Inc. 4 Written by Jim Meyering <meyering@ascend.com>, 1998. 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 3 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, see <http://www.gnu.org/licenses/>. */ 18 19 /* A generic hash table package. */ 20 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. */ 23 24 #ifndef HASH_H_ 25 # define HASH_H_ 26 27 # include <stdio.h> 28 # include <stdbool.h> 29 30 /* The __attribute__ feature is available in gcc versions 2.5 and later. 31 The warn_unused_result attribute appeared first in gcc-3.4.0. */ 32 # if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 4) 33 # define _GL_ATTRIBUTE_WUR __attribute__ ((__warn_unused_result__)) 34 # else 35 # define _GL_ATTRIBUTE_WUR /* empty */ 36 # endif 37 38 typedef size_t (*Hash_hasher) (const void *, size_t); 39 typedef bool (*Hash_comparator) (const void *, const void *); 40 typedef void (*Hash_data_freer) (void *); 41 typedef bool (*Hash_processor) (void *, void *); 42 43 struct hash_tuning 44 { 45 /* This structure is mainly used for `hash_initialize', see the block 46 documentation of `hash_reset_tuning' for more complete comments. */ 47 48 float shrink_threshold; /* ratio of used buckets to trigger a shrink */ 49 float shrink_factor; /* ratio of new smaller size to original size */ 50 float growth_threshold; /* ratio of used buckets to trigger a growth */ 51 float growth_factor; /* ratio of new bigger size to original size */ 52 bool is_n_buckets; /* if CANDIDATE really means table size */ 53 }; 54 55 typedef struct hash_tuning Hash_tuning; 56 57 struct hash_table; 58 59 typedef struct hash_table Hash_table; 60 61 /* Information and lookup. */ 62 size_t hash_get_n_buckets (const Hash_table *); 63 size_t hash_get_n_buckets_used (const Hash_table *); 64 size_t hash_get_n_entries (const Hash_table *); 65 size_t hash_get_max_bucket_length (const Hash_table *); 66 bool hash_table_ok (const Hash_table *); 67 void hash_print_statistics (const Hash_table *, FILE *); 68 void *hash_lookup (const Hash_table *, const void *); 69 70 /* Walking. */ 71 void *hash_get_first (const Hash_table *); 72 void *hash_get_next (const Hash_table *, const void *); 73 size_t hash_get_entries (const Hash_table *, void **, size_t); 74 size_t hash_do_for_each (const Hash_table *, Hash_processor, void *); 75 76 /* Allocation and clean-up. */ 77 size_t hash_string (const char *, size_t); 78 void hash_reset_tuning (Hash_tuning *); 79 Hash_table *hash_initialize (size_t, const Hash_tuning *, 80 Hash_hasher, Hash_comparator, 81 Hash_data_freer) _GL_ATTRIBUTE_WUR; 82 void hash_clear (Hash_table *); 83 void hash_free (Hash_table *); 84 85 /* Insertion and deletion. */ 86 bool hash_rehash (Hash_table *, size_t) _GL_ATTRIBUTE_WUR; 87 void *hash_insert (Hash_table *, const void *) _GL_ATTRIBUTE_WUR; 88 int hash_insert0 (Hash_table *table, const void *entry, 89 const void **matched_ent); 90 void *hash_delete (Hash_table *, const void *); 91 92 #endif 93