#ifndef _LINUX_PRIO_HEAP_H

#define _LINUX_PRIO_HEAP_H

/*

 * Simple insertion-only static-sized priority heap containing

 * pointers, based on CLR, chapter 7

 */

#include <linux/gfp.h>

/**

 * struct ptr_heap - simple static-sized priority heap

 * @ptrs - pointer to data area

 * @max - max number of elements that can be stored in @ptrs

 * @size - current number of valid elements in @ptrs (in the range 0..@size-1

 * @gt: comparison operator, which should implement "greater than"

 */

struct ptr_heap {

	void **ptrs;

	int max;

	int size;

	int (*gt)(void *, void *);

};

/**

 * heap_init - initialize an empty heap with a given memory size

 * @heap: the heap structure to be initialized

 * @size: amount of memory to use in bytes

 * @gfp_mask: mask to pass to kmalloc()

 * @gt: comparison operator, which should implement "greater than"

 */

extern int heap_init(struct ptr_heap *heap, size_t size, gfp_t gfp_mask,

		     int (*gt)(void *, void *));

/**

 * heap_free - release a heap's storage

 * @heap: the heap structure whose data should be released

 */

void heap_free(struct ptr_heap *heap);

/**

 * heap_insert - insert a value into the heap and return any overflowed value

 * @heap: the heap to be operated on

 * @p: the pointer to be inserted

 *

 * Attempts to insert the given value into the priority heap. If the

 * heap is full prior to the insertion, then the resulting heap will

 * consist of the smallest @max elements of the original heap and the

 * new element; the greatest element will be removed from the heap and

 * returned. Note that the returned element will be the new element

 * (i.e. no change to the heap) if the new element is greater than all

 * elements currently in the heap.

 */

extern void *heap_insert(struct ptr_heap *heap, void *p);

#endif /* _LINUX_PRIO_HEAP_H */