This patch introduces the concept of ABI version in the client API.
The concept will serve to guide frontend/backend interactions so that
version negotiation cal ne implemented and messages are sent using
a compatible serialization format.
Change-Id: I90f9fa70c745c62350960ce151cd116e14b5208a
Signed-off-by: Robert Varga <rovarga@cisco.com>
--- /dev/null
+/*
+ * 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.access;
+
+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 the client access API.
+ *
+ * @author Robert Varga
+ */
+@Beta
+public enum ABIVersion 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;
+
+ ABIVersion(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 ABI 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 ABIVersion}
+ */
+ public static @Nonnull ABIVersion current() {
+ return BORON;
+ }
+
+ /**
+ * Return the {@link ABIVersion} corresponding to an unsigned short integer. This method is provided for callers
+ * which provide their own recovery strategy in case of version incompatibility.
+ *
+ * @param s Short integer as returned from {@link #shortValue()}
+ * @return {@link ABIVersion}
+ * @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
+ */
+ public static @Nonnull ABIVersion valueOf(final short s) throws FutureVersionException, PastVersionException {
+ switch (Short.toUnsignedInt(s)) {
+ case 0:
+ case 1:
+ case 2:
+ case 3:
+ case 4:
+ throw new PastVersionException(s, BORON);
+ case 5:
+ return BORON;
+ default:
+ throw new FutureVersionException(s, BORON);
+ }
+ }
+
+ @Override
+ public void writeTo(final DataOutput out) throws IOException {
+ out.writeShort(value);
+ }
+
+ /**
+ * Read an {@link ABIVersion} 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 ABIVersion}
+ * @throws IOException If read fails or an unsupported version is encountered
+ */
+ public static @Nonnull ABIVersion readFrom(final @Nonnull DataInput in) throws IOException {
+ final short s = in.readShort();
+ try {
+ return valueOf(s);
+ } catch (FutureVersionException | PastVersionException e) {
+ throw new IOException("Unsupported version", e);
+ }
+ }
+}
--- /dev/null
+/*
+ * 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.access;
+
+import com.google.common.annotations.Beta;
+import com.google.common.base.Preconditions;
+import javax.annotation.Nonnull;
+
+/**
+ * Abstract base exception used for reporting version mismatches from {@link ABIVersion}.
+ *
+ * @author Robert Varga
+ */
+@Beta
+public abstract class AbstractVersionException extends Exception {
+ private static final long serialVersionUID = 1L;
+ private final ABIVersion closestVersion;
+ private final int version;
+
+ AbstractVersionException(final String message, final short version, final ABIVersion closestVersion) {
+ super(message);
+ this.closestVersion = Preconditions.checkNotNull(closestVersion);
+ this.version = Short.toUnsignedInt(version);
+ }
+
+ /**
+ * Return the numeric version which has caused this exception.
+ *
+ * @return Numeric version
+ */
+ public final int getVersion() {
+ return version;
+ }
+
+ /**
+ * Return the closest version supported by this codebase.
+ *
+ * @return Closest supported {@link ABIVersion}
+ */
+ public final @Nonnull ABIVersion getClosestVersion() {
+ return closestVersion;
+ }
+
+}
--- /dev/null
+/*
+ * 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.access;
+
+import com.google.common.annotations.Beta;
+
+/**
+ * Exception thrown from {@link ABIVersion#valueOf(short)} when the specified version is too new to be supported
+ * by the codebase.
+ *
+ * @author Robert Varga
+ */
+@Beta
+public final class FutureVersionException extends AbstractVersionException {
+ private static final long serialVersionUID = 1L;
+
+ FutureVersionException(final short version, ABIVersion closest) {
+ super("Version " + Short.toUnsignedInt(version) + " is too new", version, closest);
+ }
+}
--- /dev/null
+/*
+ * 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.access;
+
+import com.google.common.annotations.Beta;
+
+/**
+ * Exception thrown from {@link ABIVersion#valueOf(short)} when the specified version is too old and no longer
+ * supported by the codebase.
+ *
+ * @author Robert Varga
+ */
+@Beta
+public final class PastVersionException extends AbstractVersionException {
+ private static final long serialVersionUID = 1L;
+
+ PastVersionException(final short version, final ABIVersion closest) {
+ super("Version " + Short.toUnsignedInt(version) + " is too old", version, closest);
+ }
+}
--- /dev/null
+/*
+ * 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
+ */
+/**
+ * This package contains the base definitions of the APIs exposed by the clustered data store backend.
+ *
+ * @author Robert Varga
+ */
+package org.opendaylight.controller.cluster.access;
\ No newline at end of file
--- /dev/null
+/*
+ * 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.access;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+import static org.opendaylight.controller.cluster.access.ABIVersion.BORON;
+import static org.opendaylight.controller.cluster.access.ABIVersion.TEST_FUTURE_VERSION;
+import static org.opendaylight.controller.cluster.access.ABIVersion.TEST_PAST_VERSION;
+import com.google.common.io.ByteArrayDataOutput;
+import com.google.common.io.ByteStreams;
+import java.io.IOException;
+import org.junit.Test;
+
+public class ABIVersionTest {
+ @Test
+ public void testInvalidVersions() {
+ assertTrue(TEST_PAST_VERSION.compareTo(TEST_FUTURE_VERSION) < 0);
+ assertTrue(TEST_PAST_VERSION.compareTo(BORON) < 0);
+ assertTrue(TEST_FUTURE_VERSION.compareTo(BORON) > 0);
+ }
+
+ @Test
+ public void testBoronVersion() throws Exception {
+ assertEquals((short)5, BORON.shortValue());
+ assertEquals(BORON, ABIVersion.valueOf(BORON.shortValue()));
+ assertEquals(BORON, ABIVersion.readFrom(ByteStreams.newDataInput(writeVersion(BORON))));
+ }
+
+ @Test(expected=PastVersionException.class)
+ public void testInvalidPastVersion() throws Exception {
+ ABIVersion.valueOf(TEST_PAST_VERSION.shortValue());
+ }
+
+ @Test(expected=FutureVersionException.class)
+ public void testInvalidFutureVersion() throws Exception {
+ ABIVersion.valueOf(TEST_FUTURE_VERSION.shortValue());
+ }
+
+ private static byte[] writeVersion(final ABIVersion version) {
+ final ByteArrayDataOutput bado = ByteStreams.newDataOutput();
+ bado.writeShort(version.shortValue());
+ return bado.toByteArray();
+ }
+
+ @Test(expected=IOException.class)
+ public void testBadRead() throws IOException {
+ ABIVersion.readFrom(ByteStreams.newDataInput(writeVersion(TEST_PAST_VERSION)));
+ }
+}
Code Review / controller.git / commitdiff