1 /* hash - hashing table processing. 2 Copyright (C) 1998-1999, 2001, 2003, 2009-2012 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 # ifndef _GL_ATTRIBUTE_DEPRECATED 39 /* The __attribute__((__deprecated__)) feature 40 is available in gcc versions 3.1 and newer. */ 41 # if __GNUC__ < 3 || (__GNUC__ == 3 && __GNUC_MINOR__ < 1) 42 # define _GL_ATTRIBUTE_DEPRECATED /* empty */ 43 # else 44 # define _GL_ATTRIBUTE_DEPRECATED __attribute__ ((__deprecated__)) 45 # endif 46 # endif 47 48 typedef size_t (*Hash_hasher) (const void *, size_t); 49 typedef bool (*Hash_comparator) (const void *, const void *); 50 typedef void (*Hash_data_freer) (void *); 51 typedef bool (*Hash_processor) (void *, void *); 52 53 struct hash_tuning 54 { 55 /* This structure is mainly used for 'hash_initialize', see the block 56 documentation of 'hash_reset_tuning' for more complete comments. */ 57 58 float shrink_threshold; /* ratio of used buckets to trigger a shrink */ 59 float shrink_factor; /* ratio of new smaller size to original size */ 60 float growth_threshold; /* ratio of used buckets to trigger a growth */ 61 float growth_factor; /* ratio of new bigger size to original size */ 62 bool is_n_buckets; /* if CANDIDATE really means table size */ 63 }; 64 65 typedef struct hash_tuning Hash_tuning; 66 67 struct hash_table; 68 69 typedef struct hash_table Hash_table; 70 71 /* Information and lookup. */ 72 size_t hash_get_n_buckets (const Hash_table *) _GL_ATTRIBUTE_PURE; 73 size_t hash_get_n_buckets_used (const Hash_table *) _GL_ATTRIBUTE_PURE; 74 size_t hash_get_n_entries (const Hash_table *) _GL_ATTRIBUTE_PURE; 75 size_t hash_get_max_bucket_length (const Hash_table *) _GL_ATTRIBUTE_PURE; 76 bool hash_table_ok (const Hash_table *) _GL_ATTRIBUTE_PURE; 77 void hash_print_statistics (const Hash_table *, FILE *); 78 void *hash_lookup (const Hash_table *, const void *); 79 80 /* Walking. */ 81 void *hash_get_first (const Hash_table *) _GL_ATTRIBUTE_PURE; 82 void *hash_get_next (const Hash_table *, const void *); 83 size_t hash_get_entries (const Hash_table *, void **, size_t); 84 size_t hash_do_for_each (const Hash_table *, Hash_processor, void *); 85 86 /* Allocation and clean-up. */ 87 size_t hash_string (const char *, size_t) _GL_ATTRIBUTE_PURE; 88 void hash_reset_tuning (Hash_tuning *); 89 Hash_table *hash_initialize (size_t, const Hash_tuning *, 90 Hash_hasher, Hash_comparator, 91 Hash_data_freer) _GL_ATTRIBUTE_WUR; 92 void hash_clear (Hash_table *); 93 void hash_free (Hash_table *); 94 95 /* Insertion and deletion. */ 96 bool hash_rehash (Hash_table *, size_t) _GL_ATTRIBUTE_WUR; 97 void *hash_insert (Hash_table *, const void *) _GL_ATTRIBUTE_WUR; 98 99 /* Deprecate this interface. It has been renamed to hash_insert_if_absent. */ 100 int hash_insert0 (Hash_table *table, /* FIXME: remove in 2013 */ 101 const void *entry, 102 const void **matched_ent) _GL_ATTRIBUTE_DEPRECATED; 103 int hash_insert_if_absent (Hash_table *table, const void *entry, 104 const void **matched_ent); 105 void *hash_delete (Hash_table *, const void *); 106 107 #endif 108