Copyright (c) 2000, 2016 IBM Corporation and others.
This program and the accompanying materials
are made available under the terms of the Eclipse Public License 2.0
which accompanies this distribution, and is available at
https://www.eclipse.org/legal/epl-2.0/
SPDX-License-Identifier: EPL-2.0
Contributors:
    IBM Corporation - initial API and implementation
    James Blackburn (Broadcom Corp.) - ongoing development
    Lars Vogel  - Bug 473427
    Mickael Istria (Red Hat Inc.) - Bug 488937
/*******************************************************************************
 * Copyright (c) 2000, 2016 IBM Corporation and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *     James Blackburn (Broadcom Corp.) - ongoing development
 *     Lars Vogel <Lars.Vogel@vogella.com> - Bug 473427
 *     Mickael Istria (Red Hat Inc.) - Bug 488937
 *******************************************************************************/
package org.eclipse.core.internal.resources;

import java.io.DataInputStream;
import java.io.IOException;
import java.util.HashSet;
import java.util.Set;
import org.eclipse.core.internal.utils.Messages;
import org.eclipse.core.resources.IResourceStatus;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.QualifiedName;
import org.eclipse.osgi.util.NLS;

This class is used to read sync info from disk. Subclasses implement
version specific reading code.
/**
 * This class is used to read sync info from disk. Subclasses implement
 * version specific reading code.
 */
public class SyncInfoReader {
	protected Workspace workspace;
	protected Synchronizer synchronizer;

	public SyncInfoReader(Workspace workspace, Synchronizer synchronizer) {
		super();
		this.workspace = workspace;
		this.synchronizer = synchronizer;
	}

	
Returns the appropriate reader for the given version.
/**
	 * Returns the appropriate reader for the given version.
	 */
	protected SyncInfoReader getReader(int formatVersion) throws IOException {
		switch (formatVersion) {
			case 2 :
				return new SyncInfoReader_2(workspace, synchronizer);
			case 3 :
				return new SyncInfoReader_3(workspace, synchronizer);
			default :
				throw new IOException(NLS.bind(Messages.resources_format, formatVersion));
		}
	}

	public void readPartners(DataInputStream input) throws CoreException {
		try {
			int size = input.readInt();
			Set<QualifiedName> registry = new HashSet<>(size);
			for (int i = 0; i < size; i++) {
				String qualifier = input.readUTF();
				String local = input.readUTF();
				registry.add(new QualifiedName(qualifier, local));
			}
			synchronizer.setRegistry(registry);
		} catch (IOException e) {
			String message = NLS.bind(Messages.resources_readSync, e);
			throw new ResourceException(new ResourceStatus(IResourceStatus.INTERNAL_ERROR, message));
		}
	}

	public void readSyncInfo(DataInputStream input) throws IOException, CoreException {
		// dispatch to the appropriate reader depending
		// on the version of the file
		int formatVersion = readVersionNumber(input);
		SyncInfoReader reader = getReader(formatVersion);
		reader.readSyncInfo(input);
	}

	protected static int readVersionNumber(DataInputStream input) throws IOException {
		return input.readInt();
	}
}