/*------------------------------------------------------------------------------
*
* Copyright (c) 2011, EURid. All rights reserved.
* The YADIFA TM software product is provided under the BSD 3-clause license:
* 
* 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 EURid nor the names of its 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 HOLDER 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.
*
*------------------------------------------------------------------------------
*
*/
/** @defgroup collections Generic collections functions
 *  @ingroup dnscore
 *  @brief 
 *
 *  A collection of strings based on the AVL
 *
 * @{
 *
 *----------------------------------------------------------------------------*/

#ifndef _STRING_SET_H
#define	_STRING_SET_H

#ifdef	__cplusplus
extern "C"
{
#endif

/*
 * A digest is stored prefixed with its length ([1;255])
 */

/*
 * A structure to hold both children with direct access
 */

typedef struct string_node string_node;


struct string_children
{
    struct string_node* left;
    struct string_node* right;
};

/*
 * An union to have access to the children with direct or indexed access
 */

typedef union string_children_union string_children_union;

union string_children_union
{
    struct string_children lr;
    struct string_node * child[2];
};


/*
 * The node structure CANNOT have a varying size on a given collection
 * This means that the digest size is a constant in the whole tree
 */

struct string_node
{
    union string_children_union children;   /* 2 ptrs */
    const char* key;                        /* 1 ptr  */
    u16 value;                              /* 2 b */
    s8 balance;                             /* 1 b */
};                                          /* 27 OR 15 bytes (64/32) */

/*
 * AVL definition part begins here
 */

/*
 * The maximum depth of a tree.
 * 40 is enough for storing 433494436 items (worst case)
 *
 * Depth 0 is one node.
 *
 * Worst case : N is enough for sum[n = 0,N](Fn) where F is Fibonacci
 * Best case : N is enough for (2^(N+1))-1
 */
#define AVL_MAX_DEPTH   20 /* 64 */

/*
 * The previx that will be put in front of each function name
 */
#define AVL_PREFIX	    string_set_

typedef string_node* string_set;

/*
 * The type that hold the node
 */
#define AVL_NODE_TYPE   string_node

/*
 * The type that hold the tree (should be AVL_NODE_TYPE*)
 */
#define AVL_TREE_TYPE   AVL_NODE_TYPE*

/*
 * The type that hold the tree (should be AVL_NODE_TYPE*)
 */
#define AVL_CONST_TREE_TYPE AVL_NODE_TYPE * const

/*
 * How to find the root in the tree
 */
#define AVL_TREE_ROOT(__tree__) (*(__tree__))

/*
 * The type used for comparing the nodes.
 */
#define AVL_REFERENCE_TYPE const char*

#define AVL_REFERENCE_IS_CONST TRUE

/*
 * The node has got a pointer to its parent
 *
 * 0   : disable
 * !=0 : enable
 */
#define AVL_HAS_PARENT_POINTER 0

#ifdef	__cplusplus
}
#endif

#include <dnscore/avl.h.inc>

#ifdef	__cplusplus
extern "C"
{
#endif
    
/*
 * I recommand setting a define to identify the C part of the template
 * So it can be used to undefine what is not required anymore for every
 * C file but that one.
 *
 */

#define STRING_SET_EMPTY NULL
    
#ifndef _STRING_SET_C

#undef AVL_MAX_DEPTH
#undef AVL_PREFIX
#undef AVL_NODE_TYPE
#undef AVL_TREE_TYPE
#undef AVL_CONST_TREE_TYPE
#undef AVL_TREE_ROOT
#undef AVL_REFERENCE_TYPE
#undef AVL_HAS_PARENT_POINTER

#undef _AVL_H_INC

#endif	/* _STRING_SET_C */

#ifdef	__cplusplus
}
#endif

#endif	/* _STRING_SET_H */
/** @} */

/*----------------------------------------------------------------------------*/

