1 /* hash - hashing table processing. 2 Copyright (C) 1998, 1999, 2001, 2003 Free Software Foundation, Inc. 3 Written by Jim Meyering <meyering (at) ascend.com>, 1998. 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, or (at your option) 8 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 Foundation, 17 Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */ 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 typedef size_t (*Hash_hasher) (const void *, size_t); 31 typedef bool (*Hash_comparator) (const void *, const void *); 32 typedef void (*Hash_data_freer) (void *); 33 typedef bool (*Hash_processor) (void *, void *); 34 35 struct hash_entry 36 { 37 void *data; 38 struct hash_entry *next; 39 }; 40 41 struct hash_tuning 42 { 43 /* This structure is mainly used for `hash_initialize', see the block 44 documentation of `hash_reset_tuning' for more complete comments. */ 45 46 float shrink_threshold; /* ratio of used buckets to trigger a shrink */ 47 float shrink_factor; /* ratio of new smaller size to original size */ 48 float growth_threshold; /* ratio of used buckets to trigger a growth */ 49 float growth_factor; /* ratio of new bigger size to original size */ 50 bool is_n_buckets; /* if CANDIDATE really means table size */ 51 }; 52 53 typedef struct hash_tuning Hash_tuning; 54 55 struct hash_table; 56 57 typedef struct hash_table Hash_table; 58 59 /* Information and lookup. */ 60 size_t hash_get_n_buckets (const Hash_table *); 61 size_t hash_get_n_buckets_used (const Hash_table *); 62 size_t hash_get_n_entries (const Hash_table *); 63 size_t hash_get_max_bucket_length (const Hash_table *); 64 bool hash_table_ok (const Hash_table *); 65 void hash_print_statistics (const Hash_table *, FILE *); 66 void *hash_lookup (const Hash_table *, const void *); 67 68 /* Walking. */ 69 void *hash_get_first (const Hash_table *); 70 void *hash_get_next (const Hash_table *, const void *); 71 size_t hash_get_entries (const Hash_table *, void **, size_t); 72 size_t hash_do_for_each (const Hash_table *, Hash_processor, void *); 73 74 /* Allocation and clean-up. */ 75 size_t hash_string (const char *, size_t); 76 void hash_reset_tuning (Hash_tuning *); 77 Hash_table *hash_initialize (size_t, const Hash_tuning *, 78 Hash_hasher, Hash_comparator, 79 Hash_data_freer); 80 void hash_clear (Hash_table *); 81 void hash_free (Hash_table *); 82 83 /* Insertion and deletion. */ 84 bool hash_rehash (Hash_table *, size_t); 85 void *hash_insert (Hash_table *, const void *); 86 void *hash_delete (Hash_table *, const void *); 87 88 #endif 89
