db_dict_abs.h

著名的 helix realplayer 基于手机 symbian 系统的 播放器全套源代码

/* ***** BEGIN LICENSE BLOCK ***** 
 * Version: RCSL 1.0/RPSL 1.0 
 *  
 * Portions Copyright (c) 1995-2002 RealNetworks, Inc. All Rights Reserved. 
 *      
 * The contents of this file, and the files included with this file, are 
 * subject to the current version of the RealNetworks Public Source License 
 * Version 1.0 (the "RPSL") available at 
 * http://www.helixcommunity.org/content/rpsl unless you have licensed 
 * the file under the RealNetworks Community Source License Version 1.0 
 * (the "RCSL") available at http://www.helixcommunity.org/content/rcsl, 
 * in which case the RCSL will apply. You may also obtain the license terms 
 * directly from RealNetworks.  You may not use this file except in 
 * compliance with the RPSL or, if you have a valid RCSL with RealNetworks 
 * applicable to this file, the RCSL.  Please see the applicable RPSL or 
 * RCSL for the rights, obligations and limitations governing use of the 
 * contents of the file.  
 *  
 * This file is part of the Helix DNA Technology. RealNetworks is the 
 * developer of the Original Code and owns the copyrights in the portions 
 * it created. 
 *  
 * This file, and the files included with this file, is distributed and made 
 * available on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER 
 * EXPRESS OR IMPLIED, AND REALNETWORKS HEREBY DISCLAIMS ALL SUCH WARRANTIES, 
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, FITNESS 
 * FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. 
 * 
 * Technology Compatibility Kit Test Suite(s) Location: 
 *    http://www.helixcommunity.org/content/tck 
 * 
 * Contributor(s): 
 *  
 * ***** END LICENSE BLOCK ***** */ 

#ifndef _DB_DICT_ABS_H_
#define _DB_DICT_ABS_H_

#include "hxtypes.h"

/*
 * db_dict_abs.h
 *
 * abstract base class defining the api for the underlying database
 * implementation.
 */

extern UINT32 hash_torek(const char*key);

typedef UINT32 		Keytype;

class DB_node;
class Property;

class DB_implem
{
public:
    			DB_implem();
    			DB_implem(DB_node* parent, 
				UINT32 size,
	 			UINT32(*hash)(const char*), 
				int(*comp)(const char*, const char*));
    virtual 		~DB_implem();

    // add a node to the database and return the node pointer
    virtual DB_node*  	add(char* key_str, Property* new_p) = 0;

    // remove the node from the database and return its object
    virtual UINT32 	del(const char* key_str) = 0;
    virtual UINT32 	del(DB_node* node) = 0;

    // return the first non-null node in the database
    virtual DB_node* 	first() = 0;

    virtual DB_node* 	find(char* key_str) = 0;

    // return the non-null node after node "d"
    virtual DB_node* 	next(DB_node* d) = 0;

    virtual UINT32 	hash(const char* str) const = 0;
    virtual DB_node*	owner_node() const = 0;

    virtual UINT32 	size() const = 0;
    virtual int 	count() const = 0;

protected:
    // string comparison function
    int	    	 	(*_compare)(const char*,const char*);
    // hashing function
    UINT32 		(*_hash)(const char*);
    // initial size for buckets/list elements/...
    UINT32		_size;
    // number of elements in the database
    int			_count;
    // parent node which contains this dictionary
    DB_node*		_owner_node;
};

inline
DB_implem::DB_implem()
	 : _compare(0), _hash(0),  _size(0), _count(0), _owner_node(0)
{
}

inline
DB_implem::DB_implem(DB_node* owner_node, UINT32 size,
		     UINT32(*hash)(const char*),
		     int(*comp)(const char*,const char*))
	 : _compare(comp), _hash(hash),  _size(size), _count(0), 
	   _owner_node(owner_node)
{
}

inline
DB_implem::~DB_implem()
{
}

#endif // _DB_DICT_ABS_H_