jgit/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/reftable/RefCursor.java

/*
 * Copyright (C) 2017, 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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package org.eclipse.jgit.internal.storage.reftable;

import java.io.IOException;

import org.eclipse.jgit.lib.Ref;

/** Iterator over references inside a {@link Reftable}. */
public abstract class RefCursor implements AutoCloseable {
	/**
	 * Check if another reference is available.
	 *
	 * @return {@code true} if there is another result.
	 * @throws IOException
	 *             references cannot be read.
	 */
	public abstract boolean next() throws IOException;

	/** @return reference at the current position. */
	public abstract Ref getRef();

	/** @return updateIndex that last modified the current reference, */
	public abstract long getUpdateIndex();

	/** @return {@code true} if the current reference was deleted. */
	public boolean wasDeleted() {
		Ref r = getRef();
		return r.getStorage() == Ref.Storage.NEW && r.getObjectId() == null;
	}

	@Override
	public abstract void close();
}