repos_ecs/其他2015后/日志库/log4cproj_c/Log4C/sd/hash.h

/* $Id$
*
* Copyright 2001-2003, Meiosys (www.meiosys.com). All rights reserved.
* Author: Marc Vertes <mvertes@meiosys.com>
* See the COPYING file for the terms of usage and distribution.
*/

#ifndef __sd_hash_h
#define __sd_hash_h

/**
* @file hash.h
*
* @brief Generic hash table. It is implemented as an array of doubly-linked
* lists of iterators. The index within the array is computed by a efficient
* hash function.
*/

#include <stddef.h>
#include "sd/defs.h"

__SD_BEGIN_DECLS

struct __sd_hash_ops {
	unsigned int	(*hash)			(const void*);
	int				(*compare)		(const void*, const void*);
	void*			(*key_dup)		(const void*);
	void			(*key_free)		(void*);
	void*			(*data_dup)		(const void*);
	void			(*data_free)	(void*);
};

/**
* This structure holds hash table operations.
*/
typedef struct __sd_hash_ops sd_hash_ops_t;

/**
* This is the hash table.
*/
typedef struct __sd_hash sd_hash_t;

struct __sd_hash_iter {
	void*			key;
	void*			data;
	struct __sd_hash*		hash;
	unsigned int		__hkey;
	struct __sd_hash_iter*	__next;
	struct __sd_hash_iter*	__prev;
	int				__foreach;
};

/**
* This is the elementary container for storing data into the hash table.
*/
typedef struct __sd_hash_iter sd_hash_iter_t;

/**
* Signature of a "foreach" function.
*/
typedef unsigned int (*sd_hash_func_t)(void* a_key, void* a_data, void* a_userdata);

/**
* Creates a new hash table. One can customize the memory (de)allocation
* policy for keys and data stored in the hash table.
* @param a_size the initial size of the array.
* @param a_ops the hash operations. If NULL, then string keys are assumed and
* no memory (de)allocation is performed for keys and data.
* @return a dynamicaly allocated hash table.
*/
extern sd_hash_t* sd_hash_new(size_t a_size, const sd_hash_ops_t* a_ops);

/**
* Destroys the hash table.
*/
extern void sd_hash_delete(sd_hash_t* a_this);

/**
* clears the hash table.
*/
extern void sd_hash_clear(sd_hash_t* a_this);

/**
* Looks for the iterator associated to the given key in the hash table.
* @param a_key the key associated to the iterator.
* @return a pointer to the found iterator or NULL.
*/
extern sd_hash_iter_t* sd_hash_lookup(sd_hash_t* a_this, const void* a_key);

/**
* Looks for the iterator associated to the given key in the hash table and
* creates it if doesn't exist.
* @param a_key the key associated to the iterator.
* @return a pointer to the found iterator or NULL.
*/
extern sd_hash_iter_t* sd_hash_lookadd(sd_hash_t* a_this, const void* a_key);

/**
* Adds data associated with the given key into the hash table. If the
* key already exists, the old iterator is freed according to the memory
* management operations passed to sd_hash_new().
* @param a_key the key associated to the iterator.
* @return a pointer to the created or found iterator.
*/
extern sd_hash_iter_t* sd_hash_add(sd_hash_t* a_this, const void* a_key, void* a_data);

/**
* Removes an iterator from the hash table.
* @param a_key the key associated to the iterator.
*/
extern void sd_hash_del(sd_hash_t* a_this, const void* a_key);

/**
* Calls \a a_func for each element of the hash table, as long as \a a_func
* returns 0.
* @param a_func the "foreach" function.
* @param a_data the user data passed to \a a_func.
*/
extern void sd_hash_foreach(sd_hash_t* a_this, sd_hash_func_t a_func, void* a_data);

/**
* Gets the number of iterators.
*/
extern unsigned int sd_hash_get_nelem(sd_hash_t* a_this);

/**
* Gets the size of the array.
*/
extern unsigned int sd_hash_get_size(sd_hash_t* a_this);

/**
* Gets the first iterator.
*/
extern sd_hash_iter_t* sd_hash_begin(sd_hash_t* a_this);

/**
* Gets the last iterator.
*/
extern sd_hash_iter_t* sd_hash_end(sd_hash_t* a_this);

/**
* Gets a pointer to the next iterator.
*/
extern sd_hash_iter_t* sd_hash_iter_next(sd_hash_iter_t* a_this);

/**
* Gets a pointer to the previous iterator.
*/
extern sd_hash_iter_t* sd_hash_iter_prev(sd_hash_iter_t* a_this);

/**
* Gets a pointer to the previous iterator.
*/
extern void sd_hash_iter_del(sd_hash_iter_t* a_this);

/**
* Hashes strings.
*/
extern unsigned int sd_hash_hash_string(const TCHAR* a_string);

__SD_END_DECLS

#endif