diff options
Diffstat (limited to 'src/libstrongswan/utils/hashtable.h')
-rw-r--r-- | src/libstrongswan/utils/hashtable.h | 116 |
1 files changed, 116 insertions, 0 deletions
diff --git a/src/libstrongswan/utils/hashtable.h b/src/libstrongswan/utils/hashtable.h new file mode 100644 index 000000000..3d3005e73 --- /dev/null +++ b/src/libstrongswan/utils/hashtable.h @@ -0,0 +1,116 @@ +/* + * Copyright (C) 2008 Tobias Brunner + * Hochschule fuer Technik Rapperswil + * + * 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. See <http://www.fsf.org/copyleft/gpl.txt>. + * + * 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. + * + * $Id: hashtable.h 4762 2008-12-05 10:01:52Z martin $ + */ + +/** + * @defgroup hashtable hashtable + * @{ @ingroup utils + */ + +#ifndef HASHTABLE_H_ +#define HASHTABLE_H_ + +#include <utils/enumerator.h> + +typedef struct hashtable_t hashtable_t; + +/** + * Prototype for a function that computes the hash code from the given key. + * + * @param key key to hash + * @return hash code + */ +typedef u_int (*hashtable_hash_t)(void *key); + +/** + * Prototype for a function that compares the two keys for equality. + * + * @param key first key (the one we are looking for) + * @param other_key second key + * @return TRUE if the keys are equal + */ +typedef bool (*hashtable_equals_t)(void *key, void *other_key); + +/** + * Class implementing a hash table. + * + * General purpose hash table. This hash table is not synchronized. + */ +struct hashtable_t { + + /** + * Create an enumerator over the hash table key/value pairs. + * + * @return enumerator over (void *key, void *value) + */ + enumerator_t *(*create_enumerator) (hashtable_t *this); + + /** + * Adds the given value with the given key to the hash table, if there + * exists no entry with that key. NULL is returned in this case. + * Otherwise the existing value is replaced and the function returns the + * old value. + * + * @param key the key to store + * @param value the value to store + * @return NULL if no item was replaced, the old value otherwise + */ + void *(*put) (hashtable_t *this, void *key, void *value); + + /** + * Returns the value with the given key, if the hash table contains such an + * entry, otherwise NULL is returned. + * + * @param key the key of the requested value + * @return the value, NULL if not found + */ + void *(*get) (hashtable_t *this, void *key); + + /** + * Removes the value with the given key from the hash table and returns the + * removed value (or NULL if no such value existed). + * + * @param key the key of the value to remove + * @return the removed value, NULL if not found + */ + void *(*remove) (hashtable_t *this, void *key); + + /** + * Gets the number of items in the hash table. + * + * @return number of items + */ + u_int (*get_count) (hashtable_t *this); + + /** + * Destroys a hash table object. + */ + void (*destroy) (hashtable_t *this); + +}; + +/** + * Creates an empty hash table object. + * + * @param hash hash function + * @param equals equals function + * @param capacity initial capacity + * @return hashtable_t object. + */ +hashtable_t *hashtable_create(hashtable_hash_t hash, hashtable_equals_t equals, + u_int capacity); + +#endif /* HASHTABLE_H_ @} */ |