Ian Lance Taylor
27 years ago
7 changed files with 301 additions and 90 deletions
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/* An expandable hash tables datatype.
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Copyright (C) 1999 Free Software Foundation, Inc. |
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Contributed by Vladimir Makarov (vmakarov@cygnus.com). |
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This program is free software; you can redistribute it and/or modify |
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it under the terms of the GNU General Public License as published by |
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the Free Software Foundation; either version 2 of the License, or |
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(at your option) any later version. |
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This program is distributed in the hope that it will be useful, |
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but WITHOUT ANY WARRANTY; without even the implied warranty of |
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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GNU General Public License for more details. |
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You should have received a copy of the GNU General Public License |
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along with this program; if not, write to the Free Software |
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Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ |
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/* This package implements basic hash table functionality. It is possible
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to search for an entry, create an entry and destroy an entry. |
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Elements in the table are generic pointers. |
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The size of the table is not fixed; if the occupancy of the table |
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grows too high the hash table will be expanded. |
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The abstract data implementation is based on generalized Algorithm D |
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from Knuth's book "The art of computer programming". Hash table is |
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expanded by creation of new hash table and transferring elements from |
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the old table to the new table. */ |
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#ifndef __HASHTAB_H__ |
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#define __HASHTAB_H__ |
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#ifdef __cplusplus |
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extern "C" { |
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#endif /* __cplusplus */ |
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#include <ansidecl.h> |
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/* The hash table element is represented by the following type. */ |
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typedef const void *hash_table_entry_t; |
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/* Hash tables are of the following type. The structure
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(implementation) of this type is not needed for using the hash |
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tables. All work with hash table should be executed only through |
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functions mentioned below. */ |
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typedef struct hash_table |
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{ |
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/* Current size (in entries) of the hash table */ |
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size_t size; |
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/* Current number of elements including also deleted elements */ |
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size_t number_of_elements; |
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/* Current number of deleted elements in the table */ |
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size_t number_of_deleted_elements; |
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/* The following member is used for debugging. Its value is number
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of all calls of `find_hash_table_entry' for the hash table. */ |
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int searches; |
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/* The following member is used for debugging. Its value is number
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of collisions fixed for time of work with the hash table. */ |
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int collisions; |
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/* Pointer to function for evaluation of hash value (any unsigned value).
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This function has one parameter of type hash_table_entry_t. */ |
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unsigned (*hash_function) PARAMS ((hash_table_entry_t)); |
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/* Pointer to function for test on equality of hash table elements (two
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parameter of type hash_table_entry_t. */ |
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int (*eq_function) PARAMS ((hash_table_entry_t, hash_table_entry_t)); |
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/* Table itself */ |
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hash_table_entry_t *entries; |
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} *hash_table_t; |
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/* The prototypes of the package functions. */ |
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extern hash_table_t create_hash_table |
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PARAMS ((size_t, unsigned (*) (hash_table_entry_t), |
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int (*) (hash_table_entry_t, hash_table_entry_t))); |
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extern void delete_hash_table PARAMS ((hash_table_t)); |
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extern void empty_hash_table PARAMS ((hash_table_t)); |
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extern hash_table_entry_t *find_hash_table_entry |
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PARAMS ((hash_table_t, hash_table_entry_t, int)); |
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extern void remove_element_from_hash_table_entry PARAMS ((hash_table_t, |
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hash_table_entry_t)); |
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extern void clear_hash_table_slot PARAMS ((hash_table_t, hash_table_entry_t *)); |
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extern void traverse_hash_table PARAMS ((hash_table_t, |
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int (*) (hash_table_entry_t, void *), |
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void *)); |
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extern size_t hash_table_size PARAMS ((hash_table_t)); |
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extern size_t hash_table_elements_number PARAMS ((hash_table_t)); |
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extern int hash_table_collisions PARAMS ((hash_table_t)); |
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extern int all_hash_table_collisions PARAMS ((void)); |
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#ifdef __cplusplus |
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} |
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#endif /* __cplusplus */ |
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#endif /* __HASHTAB_H */ |
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