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Diffstat (limited to 'lib/hash.h')
| -rw-r--r-- | lib/hash.h | 103 |
1 files changed, 103 insertions, 0 deletions
diff --git a/lib/hash.h b/lib/hash.h new file mode 100644 index 0000000..b61bee6 --- /dev/null +++ b/lib/hash.h @@ -0,0 +1,103 @@ +/* hash - hashing table processing. + Copyright (C) 1998-1999, 2001, 2003, 2009-2016 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; + +int hash_insert_if_absent (Hash_table *table, const void *entry, + const void **matched_ent); +void *hash_delete (Hash_table *, const void *); + +#endif |