From d9be0f3be2d78eeeb740f59cb7e14d687215ce04 Mon Sep 17 00:00:00 2001 From: ian Date: Tue, 22 Feb 2000 16:18:13 +0000 Subject: [PATCH] Initial revision --- include/hashtab.h | 109 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 109 insertions(+) create mode 100644 include/hashtab.h diff --git a/include/hashtab.h b/include/hashtab.h new file mode 100644 index 0000000000..3990c14cbc --- /dev/null +++ b/include/hashtab.h @@ -0,0 +1,109 @@ +/* An expandable hash tables datatype. + Copyright (C) 1999 Free Software Foundation, Inc. + Contributed by Vladimir Makarov (vmakarov@cygnus.com). + +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 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, write to the Free Software +Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ + +/* This package implements basic hash table functionality. It is possible + to search for an entry, create an entry and destroy an entry. + + Elements in the table are generic pointers. + + The size of the table is not fixed; if the occupancy of the table + grows too high the hash table will be expanded. + + The abstract data implementation is based on generalized Algorithm D + from Knuth's book "The art of computer programming". Hash table is + expanded by creation of new hash table and transferring elements from + the old table to the new table. */ + +#ifndef __HASHTAB_H__ +#define __HASHTAB_H__ + +#ifdef __cplusplus +extern "C" { +#endif /* __cplusplus */ + +#include + +/* The hash table element is represented by the following type. */ + +typedef const void *hash_table_entry_t; + +/* Hash tables are of the following type. The structure + (implementation) of this type is not needed for using the hash + tables. All work with hash table should be executed only through + functions mentioned below. */ + +typedef struct hash_table +{ + /* Current size (in entries) of the hash table */ + size_t size; + /* Current number of elements including also deleted elements */ + size_t number_of_elements; + /* Current number of deleted elements in the table */ + size_t number_of_deleted_elements; + /* The following member is used for debugging. Its value is number + of all calls of `find_hash_table_entry' for the hash table. */ + int searches; + /* The following member is used for debugging. Its value is number + of collisions fixed for time of work with the hash table. */ + int collisions; + /* Pointer to function for evaluation of hash value (any unsigned value). + This function has one parameter of type hash_table_entry_t. */ + unsigned (*hash_function) PARAMS ((hash_table_entry_t)); + /* Pointer to function for test on equality of hash table elements (two + parameter of type hash_table_entry_t. */ + int (*eq_function) PARAMS ((hash_table_entry_t, hash_table_entry_t)); + /* Table itself */ + hash_table_entry_t *entries; +} *hash_table_t; + + +/* The prototypes of the package functions. */ + +extern hash_table_t create_hash_table + PARAMS ((size_t, unsigned (*) (hash_table_entry_t), + int (*) (hash_table_entry_t, hash_table_entry_t))); + +extern void delete_hash_table PARAMS ((hash_table_t)); + +extern void empty_hash_table PARAMS ((hash_table_t)); + +extern hash_table_entry_t *find_hash_table_entry + PARAMS ((hash_table_t, hash_table_entry_t, int)); + +extern void remove_element_from_hash_table_entry PARAMS ((hash_table_t, + hash_table_entry_t)); + +extern void clear_hash_table_slot PARAMS ((hash_table_t, hash_table_entry_t *)); + +extern void traverse_hash_table PARAMS ((hash_table_t, + int (*) (hash_table_entry_t, void *), + void *)); + +extern size_t hash_table_size PARAMS ((hash_table_t)); + +extern size_t hash_table_elements_number PARAMS ((hash_table_t)); + +extern int hash_table_collisions PARAMS ((hash_table_t)); + +extern int all_hash_table_collisions PARAMS ((void)); + +#ifdef __cplusplus +} +#endif /* __cplusplus */ + +#endif /* __HASHTAB_H */ -- 2.11.0