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+/* hash - hashing table processing.
+ Copyright (C) 1998, 1999, 2001, 2003 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 2, 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, write to the Free Software Foundation,
+ Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
+
+/* 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>
+
+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_entry
+ {
+ void *data;
+ struct hash_entry *next;
+ };
+
+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 *);
+size_t hash_get_n_buckets_used (const Hash_table *);
+size_t hash_get_n_entries (const Hash_table *);
+size_t hash_get_max_bucket_length (const Hash_table *);
+bool hash_table_ok (const Hash_table *);
+void hash_print_statistics (const Hash_table *, FILE *);
+void *hash_lookup (const Hash_table *, const void *);
+
+/* Walking. */
+void *hash_get_first (const Hash_table *);
+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);
+void hash_reset_tuning (Hash_tuning *);
+Hash_table *hash_initialize (size_t, const Hash_tuning *,
+ Hash_hasher, Hash_comparator,
+ Hash_data_freer);
+void hash_clear (Hash_table *);
+void hash_free (Hash_table *);
+
+/* Insertion and deletion. */
+bool hash_rehash (Hash_table *, size_t);
+void *hash_insert (Hash_table *, const void *);
+void *hash_delete (Hash_table *, const void *);
+
+#endif