/*
* Copyright (c) 2016 Cisco Systems, Inc. and others. All rights reserved.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v1.0 which accompanies this distribution,
* and is available at http://www.eclipse.org/legal/epl-v10.html
*/
package org.opendaylight.controller.cluster.datastore.persisted;
import com.google.common.annotations.Beta;
import com.google.common.annotations.VisibleForTesting;
import com.google.common.base.Preconditions;
import java.io.DataInput;
import java.io.DataOutput;
import java.io.IOException;
import javax.annotation.Nonnull;
import org.opendaylight.yangtools.concepts.WritableObject;
/**
* Enumeration of all ABI versions supported by this implementation of persistence. An ABI version has to be bumped
* whenever:
* <ul>
* <li>a new event is defined</li>
* <li>serialization format is changed</li>
* </ul>
*
* <p>
* This version effectively defines the protocol version between actors participating on a particular shard. A shard
* participant instance should oppose RAFT candidates which produce persistence of an unsupported version. If a follower
* encounters an unsupported version it must not become fully-operational, as it does not have an accurate view
* of shard state.
*
* @author Robert Varga
*/
@Beta
public enum PayloadVersion implements WritableObject {
// NOTE: enumeration values need to be sorted in asceding order of their version to keep Comparable working
/**
* Version which is older than any other version. This version exists purely for testing purposes.
*/
@VisibleForTesting
TEST_PAST_VERSION(0),
/**
* Initial ABI version, as shipped with Boron Simultaneous release.
*/
// We seed the initial version to be the same as DataStoreVersions.BORON-VERSION for compatibility reasons.
BORON(5),
/**
* Version which is newer than any other version. This version exists purely for testing purposes.
*/
@VisibleForTesting
TEST_FUTURE_VERSION(65535);
private final short value;
PayloadVersion(final int intVersion) {
Preconditions.checkArgument(intVersion >= 0 && intVersion <= 65535);
value = (short) intVersion;
}
/**
* Return the unsigned short integer identifying this version.
*
* @return Unsigned short integer identifying this version
*/
public short shortValue() {
return value;
}
/**
* Return the codebase-native persistence version. This version is the default version allocated to messages
* at runtime. Conversion to previous versions may incur additional overhead (such as object allocation).
*
* @return Current {@link PayloadVersion}
*/
@Nonnull
public static PayloadVersion current() {
return BORON;
}
/**
* Return the {@link PayloadVersion} corresponding to an unsigned short integer. This method is provided for callers
* which provide their own recovery strategy in case of version incompatibility.
*
* @param version Short integer as returned from {@link #shortValue()}
* @return {@link PayloadVersion}
* @throws FutureVersionException if the specified integer identifies a future version
* @throws PastVersionException if the specified integer identifies a past version which is no longer supported
*/
@Nonnull
public static PayloadVersion valueOf(final short version) throws FutureVersionException, PastVersionException {
switch (Short.toUnsignedInt(version)) {
case 0:
case 1:
case 2:
case 3:
case 4:
throw new PastVersionException(version, BORON);
case 5:
return BORON;
default:
throw new FutureVersionException(version, BORON);
}
}
@Override
public void writeTo(final DataOutput out) throws IOException {
out.writeShort(value);
}
/**
* Read an {@link PayloadVersion} from a {@link DataInput}. This method is provided for callers which do not have
* a recovery strategy for dealing with unsupported versions.
*
* @param in Input from which to read
* @return An {@link PayloadVersion}
* @throws IOException If read fails or an unsupported version is encountered
*/
@Nonnull
public static PayloadVersion readFrom(@Nonnull final DataInput in) throws IOException {
final short s = in.readShort();
try {
return valueOf(s);
} catch (FutureVersionException | PastVersionException e) {
throw new IOException("Unsupported version", e);
}
}
}