/*

 * Copyright (C) the libgit2 contributors.  All rights reserved.

 *

 * This file is part of libgit2, distributed under the GNU GPL v2 with

 * a Linking Exception. For full terms see the included COPYING file.

 */

#ifndef INCLUDE_pqueue_h__

#define INCLUDE_pqueue_h__

#include "vector.h"

typedef git_vector git_pqueue;

enum {

	/* flag meaning: don't grow heap, keep highest values only */

	GIT_PQUEUE_FIXED_SIZE = (GIT_VECTOR_FLAG_MAX << 1),

};

/**

 * Initialize priority queue

 *

 * @param pq The priority queue struct to initialize

 * @param flags Flags (see above) to control queue behavior

 * @param init_size The initial queue size

 * @param cmp The entry priority comparison function

 * @return 0 on success, <0 on error

 */

extern int git_pqueue_init(

	git_pqueue *pq,

	uint32_t flags,

	size_t init_size,

	git_vector_cmp cmp);

#define git_pqueue_free  git_vector_free

#define git_pqueue_clear git_vector_clear

#define git_pqueue_size  git_vector_length

#define git_pqueue_get   git_vector_get

#define git_pqueue_reverse git_vector_reverse

/**

 * Insert a new item into the queue

 *

 * @param pq The priority queue

 * @param item Pointer to the item data

 * @return 0 on success, <0 on failure

 */

extern int git_pqueue_insert(git_pqueue *pq, void *item);

/**

 * Remove the top item in the priority queue

 *

 * @param pq The priority queue

 * @return item from heap on success, NULL if queue is empty

 */

extern void *git_pqueue_pop(git_pqueue *pq);

#endif