org.eclipse.jgit/src/org/eclipse/jgit/revwalk/AsyncRevObjectQueue.java

/*
 * Copyright (C) 2010, Google Inc.
 * and other copyright owners as documented in the project's IP log.
 *
 * This program and the accompanying materials are made available
 * under the terms of the Eclipse Distribution License v1.0 which
 * accompanies this distribution, is reproduced below, and is
 * available at http://www.eclipse.org/org/documents/edl-v10.php
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 * All rights reserved.
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 * without modification, are permitted provided that the following
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 * - Redistributions of source code must retain the above copyright
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 * - Redistributions in binary form must reproduce the above
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 *   with the distribution.
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 *   names of its contributors may be used to endorse or promote
 *   products derived from this software without specific prior
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 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
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package org.eclipse.jgit.revwalk;

import java.io.IOException;

import org.eclipse.jgit.errors.MissingObjectException;
import org.eclipse.jgit.lib.AsyncOperation;

/**
 * Queue to lookup and parse objects asynchronously.
 *
 * A queue may perform background lookup of objects and supply them (possibly
 * out-of-order) to the application.
 */
public interface AsyncRevObjectQueue extends AsyncOperation {
	/**
	 * Obtain the next object.
	 *
	 * @return the object; null if there are no more objects remaining.
	 * @throws MissingObjectException
	 *             the object does not exist. There may be more objects
	 *             remaining in the iteration, the application should call
	 *             {@link #next()} again.
	 * @throws IOException
	 *             the object store cannot be accessed.
	 */
	public RevObject next() throws MissingObjectException, IOException;
}