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/*
Copyright (c) 2002, 2004, Christopher Clark
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:
* Redistributions of source code must retain the above copyright notice,
this list of conditions and the following disclaimer.
* Redistributions in binary form must reproduce the above copyright notice,
this list of conditions and the following disclaimer in the documentation
and/or other materials provided with the distribution.
* Neither the name of the original author; nor the names of any
contributors may be used to endorse or promote products derived from this
software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef __HASHTABLE_CWC22_H__
#define __HASHTABLE_CWC22_H__
#include "config.h"
struct hashtable;
/* Example of use:
*
* struct hashtable *h;
* struct some_key *k;
* struct some_value *v;
*
* static unsigned int hash_from_key_fn( void *k );
* static int keys_equal_fn ( void *key1, void *key2 );
*
* h = create_hashtable(16, hash_from_key_fn, keys_equal_fn);
* k = (struct some_key *) malloc(sizeof(struct some_key));
* v = (struct some_value *) malloc(sizeof(struct some_value));
*
* (initialise k and v to suitable values)
*
* if (! hashtable_insert(h,k,v) )
* { exit(-1); }
*
* if (NULL == (found = hashtable_search(h,k) ))
* { printf("not found!"); }
*
* if (NULL == (found = hashtable_remove(h,k) ))
* { printf("Not found\n"); }
*
*/
/* Macros may be used to define type-safe(r) hashtable access functions, with
* methods specialized to take known key and value types as parameters.
*
* Example:
*
* Insert this at the start of your file:
*
* DEFINE_HASHTABLE_INSERT(insert_some, struct some_key, struct some_value);
* DEFINE_HASHTABLE_SEARCH(search_some, struct some_key, struct some_value);
* DEFINE_HASHTABLE_REMOVE(remove_some, struct some_key, struct some_value);
*
* This defines the functions 'insert_some', 'search_some' and 'remove_some'.
* These operate just like hashtable_insert etc., with the same parameters,
* but their function signatures have 'struct some_key *' rather than
* 'void *', and hence can generate compile time errors if your program is
* supplying incorrect data as a key (and similarly for value).
*
* Note that the hash and key equality functions passed to create_hashtable
* still take 'void *' parameters instead of 'some key *'. This shouldn't be
* a difficult issue as they're only defined and passed once, and the other
* functions will ensure that only valid keys are supplied to them.
*
* The cost for this checking is increased code size and runtime overhead
* - if performance is important, it may be worth switching back to the
* unsafe methods once your program has been debugged with the safe methods.
* This just requires switching to some simple alternative defines - eg:
* #define insert_some hashtable_insert
*
*/
/*****************************************************************************
* create_hashtable
* @name create_hashtable
* @param minsize minimum initial size of hashtable
* @param hashfunction function for hashing keys
* @param key_eq_fn function for determining key equality
* @return newly created hashtable or NULL on failure
*/
struct hashtable *
create_hashtable(unsigned int minsize,
unsigned int (*hashfunction) (void*),
int (*key_eq_fn) (void*,void*));
/*****************************************************************************
* hashtable_insert
* @name hashtable_insert
* @param h the hashtable to insert into
* @param k the key - hashtable claims ownership and will free on removal
* @param v the value - does not claim ownership
* @return non-zero for successful insertion
*
* This function will cause the table to expand if the insertion would take
* the ratio of entries to table size over the maximum load factor.
*
* This function does not check for repeated insertions with a duplicate key.
* The value returned when using a duplicate key is undefined -- when
* the hashtable changes size, the order of retrieval of duplicate key
* entries is reversed.
* If in doubt, remove before insert.
*/
int
hashtable_insert(struct hashtable *h, void *k, void *v);
#define DEFINE_HASHTABLE_INSERT(fnname, keytype, valuetype) \
int fnname (struct hashtable *h, keytype *k, valuetype *v) \
{ \
return hashtable_insert(h,k,v); \
}
/*****************************************************************************
* hashtable_search
* @name hashtable_search
* @param h the hashtable to search
* @param k the key to search for - does not claim ownership
* @return the value associated with the key, or NULL if none found
*/
void *
hashtable_search(struct hashtable *h, void *k);
#define DEFINE_HASHTABLE_SEARCH(fnname, keytype, valuetype) \
valuetype * fnname (struct hashtable *h, keytype *k) \
{ \
return (valuetype *) (hashtable_search(h,k)); \
}
/*****************************************************************************
* hashtable_remove
* @name hashtable_remove
* @param h the hashtable to remove the item from
* @param k the key to search for - does not claim ownership
* @return the value associated with the key, or NULL if none found
*/
void * /* returns value */
hashtable_remove(struct hashtable *h, void *k);
#define DEFINE_HASHTABLE_REMOVE(fnname, keytype, valuetype) \
valuetype * fnname (struct hashtable *h, keytype *k) \
{ \
return (valuetype *) (hashtable_remove(h,k)); \
}
/*****************************************************************************
* hashtable_count
* @name hashtable_count
* @param h the hashtable
* @return the number of items stored in the hashtable
*/
unsigned int
hashtable_count(struct hashtable *h);
/*****************************************************************************
* hashtable_destroy
* @name hashtable_destroy
* @param h the hashtable
* @param free_values whether to call 'free' on the remaining values
*/
void
hashtable_destroy(struct hashtable *h, int free_values);
#endif /* __HASHTABLE_CWC22_H__ */
/*
* Copyright (c) 2002, Christopher Clark
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* * Neither the name of the original author; nor the names of any contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
* OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
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