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 *
 * Copyright (c) 2011-2016, EURid. All rights reserved.
 * The YADIFA TM software product is provided under the BSD 3-clause license:
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 *
 *        * Redistributions of source code must retain the above copyright 
 *          notice, this list of conditions and the following disclaimer.
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 *          documentation and/or other materials provided with the distribution.
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 *          used to endorse or promote products derived from this software 
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 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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/** @defgroup collections Generic collections functions
 *  @ingroup dnscore
 *  @brief A node-based single linked list
 *
 * A node-based single linked list
 *
 * @{
 */
/*----------------------------------------------------------------------------*/
#ifndef LIST_SL_H_
#define LIST_SL_H_

/*    ------------------------------------------------------------
 *
 *      INCLUDES
 */

#include <dnscore/sys_types.h>
#include <dnscore/zalloc.h>

/*    ------------------------------------------------------------
 *
 *      STRUCTS
 */

/**
 * Linked list for interface data
 * 
 * (looks like a no-header no-sentinel single-linked list of strings)
 * 
 * head : the base structure of the list
 * item : the concept of what is being stored in the list
 * node : holds the item
 * data : the reference to the item (which can be called data because it's type-less)
 * 
 */

typedef struct list_sl_node_s list_sl_node_s;

#define LISTSLND_TAG 0x444e4c535453494c

struct list_sl_node_s
{
    struct list_sl_node_s *next;
    void *data;
};

/// The sentiel is a butchered node, meant to avoid the (useless) data field.

typedef struct list_sl_node_sentiel_s list_sl_node_sentiel_s;

struct list_sl_node_sentiel_s
{
    struct list_sl_node_s *next;
};

typedef struct list_sl_s list_sl_s;

struct list_sl_s
{
    list_sl_node_s *first;
    list_sl_node_sentiel_s sentinel;
    u32 size;
};

/*    ------------------------------------------------------------
 *
 *      PROTOTYPES
 */

/**
 * Initialises a list.
 * 
 * @param list
 */

static inline void
list_sl_init(list_sl_s *list)
{
    list->first = (list_sl_node_s*)&list->sentinel;
    list->sentinel.next = NULL;
    list->size = 0;
}

/**
 * Adds an item at the head of the list.
 * 
 * @param list
 * @param data
 */

static inline void
list_sl_insert(list_sl_s *list, void *data)
{
    list_sl_node_s *node;
    ZALLOC_OR_DIE(list_sl_node_s*, node, list_sl_node_s, LISTSLND_TAG);
    node->next = list->first;
    node->data = data;
    list->first = node;
    list->size++;
}

/**
 * 
 * Adds an item to the list.
 * Effectively inserts the item.
 * 
 * @param list
 * @param data
 */

static inline void
list_sl_add(list_sl_s *list, void *data)
{
    list_sl_insert(list, data);
}
/*
static inline void
list_sl_add_list(list_sl_s *list, list_sl_s *list_to_append)
{
    
}
*/
/**
 * Remove the first item from the list.
 * Deletes the node but not the data.
 * The data is returned.
 * 
 * @param list
 * @return the data or NULL if the list is empty
 */

static inline void*
list_sl_remove_first(list_sl_s *list)
{
    if(list->size > 0)
    {
        list_sl_node_s *node = list->first;
        void *data = node->data;
        list->first = node->next;
        list->size--;
        ZFREE(node,list_sl_node_s);
        return data;
    }
    else
    {
        return NULL;
    }
}

/**
 * 
 * Adds an item to the list, seen as a stack.
 * Effectively inserts the item.
 * 
 * @param list
 * @param data
 */

static inline void
list_sl_push(list_sl_s *list, void *data)
{
    list_sl_insert(list, data);
}

/**
 * 
 * Adds an item to the list, seen as a stack.
 * Effectively inserts the item.
 * 
 * @param list
 * @param data
 */

static inline void*
list_sl_pop(list_sl_s *list)
{
    void *data = list_sl_remove_first(list);
    return data;
}

/**
 * Remove the first item that points to data;
 * 
 * @param list
 * @param data
 * @return TRUE if an item has been deleted
 */

bool list_sl_remove(list_sl_s *list, void *data);

/**
 * Remove all items from the list.
 * Deletes the nodes but not the data.
 * 
 * @param list
 */

void list_sl_clear(list_sl_s *list);

/**
 * Iterates through the items of the function, calling the comparator.
 * 
 * The comparator must return:
 * 
 * COLLECTION_ITEM_SKIP                 : go to next item
 * COLLECTION_ITEM_STOP                 : stop processing, return NULL
 * COLLECTION_ITEM_PROCESS_THEN_STOP    : stop processing, return node data
 * 
 * @param list
 * @param comparator
 * 
 * @return a matching node or NULL
 */

void *list_sl_search(list_sl_s *list, result_callback_function *comparator, void *parm);

/**
 * Iterates through the items of the function, calling the comparator.
 * 
 * The comparator must return:
 * 
 * COLLECTION_ITEM_SKIP                 : go to next item
 * COLLECTION_ITEM_PROCESS              : delete, then go to next item
 * COLLECTION_ITEM_STOP                 : stop processing
 * COLLECTION_ITEM_PROCESS_THEN_STOP    : delete, then stop processing
 * 
 * @param list
 * @param comparator
 * 
 * @return TRUE if at least one item has been deleted, FALSE otherwise.
 */

bool list_sl_remove_match(list_sl_s *list, result_callback_function *comparator, void *parm);

/**
 * 
 * Returns the size of the list
 * 
 * @param list
 * @return the size of the list
 */

static inline u32
list_sl_size(const list_sl_s *list)
{
    return list->size;
}
        

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

#endif /* LIST_SL_H_ */
