/* hash - hashing table processing. Copyright (C) 1998-1999, 2001, 2003, 2009-2012 Free Software Foundation, Inc. Written by Jim Meyering <meyering@ascend.com>, 1998. This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program. If not, see <http://www.gnu.org/licenses/>. */ /* A generic hash table package. */ /* Make sure USE_OBSTACK is defined to 1 if you want the allocator to use obstacks instead of malloc, and recompile 'hash.c' with same setting. */ #ifndef HASH_H_ # define HASH_H_ # include <stdio.h> # include <stdbool.h> /* The __attribute__ feature is available in gcc versions 2.5 and later. The warn_unused_result attribute appeared first in gcc-3.4.0. */ # if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 4) # define _GL_ATTRIBUTE_WUR __attribute__ ((__warn_unused_result__)) # else # define _GL_ATTRIBUTE_WUR /* empty */ # endif # ifndef _GL_ATTRIBUTE_DEPRECATED /* The __attribute__((__deprecated__)) feature is available in gcc versions 3.1 and newer. */ # if __GNUC__ < 3 || (__GNUC__ == 3 && __GNUC_MINOR__ < 1) # define _GL_ATTRIBUTE_DEPRECATED /* empty */ # else # define _GL_ATTRIBUTE_DEPRECATED __attribute__ ((__deprecated__)) # endif # endif typedef size_t (*Hash_hasher) (const void *, size_t); typedef bool (*Hash_comparator) (const void *, const void *); typedef void (*Hash_data_freer) (void *); typedef bool (*Hash_processor) (void *, void *); struct hash_tuning { /* This structure is mainly used for 'hash_initialize', see the block documentation of 'hash_reset_tuning' for more complete comments. */ float shrink_threshold; /* ratio of used buckets to trigger a shrink */ float shrink_factor; /* ratio of new smaller size to original size */ float growth_threshold; /* ratio of used buckets to trigger a growth */ float growth_factor; /* ratio of new bigger size to original size */ bool is_n_buckets; /* if CANDIDATE really means table size */ }; typedef struct hash_tuning Hash_tuning; struct hash_table; typedef struct hash_table Hash_table; /* Information and lookup. */ size_t hash_get_n_buckets (const Hash_table *) _GL_ATTRIBUTE_PURE; size_t hash_get_n_buckets_used (const Hash_table *) _GL_ATTRIBUTE_PURE; size_t hash_get_n_entries (const Hash_table *) _GL_ATTRIBUTE_PURE; size_t hash_get_max_bucket_length (const Hash_table *) _GL_ATTRIBUTE_PURE; bool hash_table_ok (const Hash_table *) _GL_ATTRIBUTE_PURE; void hash_print_statistics (const Hash_table *, FILE *); void *hash_lookup (const Hash_table *, const void *); /* Walking. */ void *hash_get_first (const Hash_table *) _GL_ATTRIBUTE_PURE; void *hash_get_next (const Hash_table *, const void *); size_t hash_get_entries (const Hash_table *, void **, size_t); size_t hash_do_for_each (const Hash_table *, Hash_processor, void *); /* Allocation and clean-up. */ size_t hash_string (const char *, size_t) _GL_ATTRIBUTE_PURE; void hash_reset_tuning (Hash_tuning *); Hash_table *hash_initialize (size_t, const Hash_tuning *, Hash_hasher, Hash_comparator, Hash_data_freer) _GL_ATTRIBUTE_WUR; void hash_clear (Hash_table *); void hash_free (Hash_table *); /* Insertion and deletion. */ bool hash_rehash (Hash_table *, size_t) _GL_ATTRIBUTE_WUR; void *hash_insert (Hash_table *, const void *) _GL_ATTRIBUTE_WUR; /* Deprecate this interface. It has been renamed to hash_insert_if_absent. */ int hash_insert0 (Hash_table *table, /* FIXME: remove in 2013 */ const void *entry, const void **matched_ent) _GL_ATTRIBUTE_DEPRECATED; int hash_insert_if_absent (Hash_table *table, const void *entry, const void **matched_ent); void *hash_delete (Hash_table *, const void *); #endif