pqueue.h 1.46 KB
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/*
Edward Thomson committed
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 * Copyright (C) the libgit2 contributors.  All rights reserved.
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 *
Vicent Marti committed
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 * This file is part of libgit2, distributed under the GNU GPL v2 with
 * a Linking Exception. For full terms see the included COPYING file.
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 */
#ifndef INCLUDE_pqueue_h__
#define INCLUDE_pqueue_h__

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#include "git2_util.h"
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#include "vector.h"
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typedef git_vector git_pqueue;
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enum {
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	/* flag meaning: don't grow heap, keep highest values only */
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	GIT_PQUEUE_FIXED_SIZE = (GIT_VECTOR_FLAG_MAX << 1)
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};
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/**
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 * Initialize priority queue
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 *
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 * @param pq The priority queue struct to initialize
 * @param flags Flags (see above) to control queue behavior
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 * @param init_size The initial queue size
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 * @param cmp The entry priority comparison function
 * @return 0 on success, <0 on error
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 */
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extern int git_pqueue_init(
	git_pqueue *pq,
	uint32_t flags,
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	size_t init_size,
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	git_vector_cmp cmp);
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#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
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#define git_pqueue_reverse git_vector_reverse
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/**
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 * 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
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 */
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extern int git_pqueue_insert(git_pqueue *pq, void *item);
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/**
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 * Remove the top item in the priority queue
 *
 * @param pq The priority queue
 * @return item from heap on success, NULL if queue is empty
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 */
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extern void *git_pqueue_pop(git_pqueue *pq);
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#endif