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/** @defgroup collections Generic collections functions
 *  @ingroup dnscore
 *  @brief A node-based single linked list
 *
 * A node-based single linked list
 *
 * @{
 */
/*----------------------------------------------------------------------------*/
#pragma once

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

#include <dnscore/sys_types.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 bpqueue_node_s bpqueue_node_s;

struct bpqueue_node_s
{
    struct bpqueue_node_s *next;
    void *data;
    u32 priority;
};

typedef struct bpqueue_s bpqueue_s;

struct bpqueue_s
{
    bpqueue_node_s *first;
    bpqueue_node_s *last;
    u32 size;
};

#define EMPTY_BPQUEUE {NULL, NULL, 0}

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

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

void bpqueue_init(bpqueue_s *list);
/**
 * Adds an item at the head of the list.
 * 
 * @param list
 * @param data
 */

void bpqueue_enqueue(bpqueue_s *list, void *data, u32 priority);

/**
 * 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
 */

void *bpqueue_dequeue(bpqueue_s *list);

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

void bpqueue_clear(bpqueue_s *list);

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

static inline u32
bpqueue_size(const bpqueue_s *list)
{
    return list->size;
}
