+/*
+ * Copyright (c) 2015 Brocade Communications 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;
+
+import static java.util.Objects.requireNonNull;
+
+import com.google.common.annotations.Beta;
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.ObjectInputStream;
+import java.util.Map;
+import java.util.Optional;
+import java.util.concurrent.ConcurrentHashMap;
+import org.opendaylight.controller.cluster.datastore.persisted.DatastoreSnapshot;
+import org.opendaylight.controller.cluster.datastore.persisted.DatastoreSnapshotList;
+import org.osgi.service.component.annotations.Activate;
+import org.osgi.service.component.annotations.Component;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * This class looks for a previously saved data store backup file in a directory and, if found, de-serializes
+ * the DatastoreSnapshot instances. This class has a static singleton that is created on bundle activation.
+ *
+ * @author Thomas Pantelis
+ */
+@Beta
+@Component(immediate = true)
+public final class DefaultDatastoreSnapshotRestore implements DatastoreSnapshotRestore {
+ private static final Logger LOG = LoggerFactory.getLogger(DefaultDatastoreSnapshotRestore.class);
+
+ private final Map<String, DatastoreSnapshot> datastoreSnapshots = new ConcurrentHashMap<>();
+ private final String restoreDirectoryPath;
+
+ public DefaultDatastoreSnapshotRestore() {
+ this("./clustered-datastore-restore");
+ }
+
+ public DefaultDatastoreSnapshotRestore(final String restoreDirectoryPath) {
+ this.restoreDirectoryPath = requireNonNull(restoreDirectoryPath);
+ }
+
+ @Override
+ public Optional<DatastoreSnapshot> getAndRemove(final String datastoreType) {
+ return Optional.ofNullable(datastoreSnapshots.remove(datastoreType));
+ }
+
+ @Activate
+ @SuppressWarnings("checkstyle:IllegalCatch")
+ void activate() {
+ final File restoreDirectoryFile = new File(restoreDirectoryPath);
+ final String[] files = restoreDirectoryFile.list();
+ if (files == null || files.length == 0) {
+ LOG.debug("Restore directory {} does not exist or is empty", restoreDirectoryFile);
+ return;
+ }
+
+ if (files.length > 1) {
+ LOG.error(
+ "Found {} files in clustered datastore restore directory {} - expected 1. No restore will be attempted",
+ files.length, restoreDirectoryFile);
+ return;
+ }
+
+ final File restoreFile = new File(restoreDirectoryFile, files[0]);
+ LOG.info("Clustered datastore will be restored from file {}", restoreFile);
+
+ try (FileInputStream fis = new FileInputStream(restoreFile)) {
+ DatastoreSnapshotList snapshots = deserialize(fis);
+ LOG.debug("Deserialized {} snapshots", snapshots.size());
+
+ for (DatastoreSnapshot snapshot: snapshots) {
+ datastoreSnapshots.put(snapshot.getType(), snapshot);
+ }
+ } catch (ClassNotFoundException | IOException e) {
+ LOG.error("Error reading clustered datastore restore file {}", restoreFile, e);
+ } finally {
+ if (!restoreFile.delete()) {
+ LOG.error("Could not delete clustered datastore restore file {}", restoreFile);
+ }
+ }
+ }
+
+ private static DatastoreSnapshotList deserialize(final InputStream inputStream)
+ throws IOException, ClassNotFoundException {
+ try (ObjectInputStream ois = new ObjectInputStream(inputStream)) {
+ return (DatastoreSnapshotList) ois.readObject();
+ }
+ }
+}