/*
* Copyright (c) 2013 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.config.persist.storage.file.xml.model;
import com.google.common.base.Optional;
import com.google.common.collect.Iterables;
import com.google.common.collect.Lists;
import com.google.common.io.Files;
import java.io.File;
import java.io.IOException;
import java.nio.charset.StandardCharsets;
import java.util.List;
import javax.xml.bind.JAXBContext;
import javax.xml.bind.JAXBException;
import javax.xml.bind.Marshaller;
import javax.xml.bind.Unmarshaller;
import javax.xml.bind.annotation.XmlElement;
import javax.xml.bind.annotation.XmlElementWrapper;
import javax.xml.bind.annotation.XmlRootElement;
import javax.xml.stream.XMLInputFactory;
import javax.xml.stream.XMLStreamException;
import javax.xml.stream.XMLStreamReader;
import javax.xml.transform.stream.StreamSource;
import org.apache.commons.lang3.StringUtils;
@XmlRootElement(name = "persisted-snapshots")
public final class Config {
private List<ConfigSnapshot> snapshots;
Config(final List<ConfigSnapshot> snapshots) {
this.snapshots = snapshots;
}
public Config() {
this.snapshots = Lists.newArrayList();
}
@XmlElement(name = "snapshot")
@XmlElementWrapper(name = "snapshots")
public List<ConfigSnapshot> getSnapshots() {
return snapshots;
}
public void setSnapshots(final List<ConfigSnapshot> snapshots) {
this.snapshots = snapshots;
}
public void toXml(final File to) {
try {
// TODO Moxy has to be used instead of default jaxb impl due to a bug
// default implementation has a bug that prevents from serializing xml in a string
JAXBContext jaxbContext = org.eclipse.persistence.jaxb.JAXBContextFactory.createContext(new Class[]{Config.class}, null);
Marshaller marshaller = jaxbContext.createMarshaller();
marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, Boolean.TRUE);
marshaller.marshal(this, to);
} catch (final JAXBException e) {
throw new PersistException("Unable to persist configuration", e);
}
}
public static Config fromXml(final File from) {
if(isEmpty(from)) {
return new Config();
}
try {
JAXBContext jaxbContext = JAXBContext.newInstance(Config.class);
Unmarshaller um = jaxbContext.createUnmarshaller();
XMLInputFactory xif = XMLInputFactory.newFactory();
xif.setProperty(XMLInputFactory.IS_SUPPORTING_EXTERNAL_ENTITIES, false);
xif.setProperty(XMLInputFactory.SUPPORT_DTD, false);
XMLStreamReader xsr = xif.createXMLStreamReader(new StreamSource(from));
return (Config) um.unmarshal(xsr);
} catch (JAXBException | XMLStreamException e) {
throw new PersistException("Unable to restore configuration", e);
}
}
private static boolean isEmpty(final File from) {
return from.length() == 0 || isBlank(from);
}
private static boolean isBlank(final File from) {
try {
return StringUtils.isBlank(Files.toString(from, StandardCharsets.UTF_8));
} catch (final IOException e) {
throw new IllegalStateException("Unexpected error reading file" + from, e);
}
}
public Optional<ConfigSnapshot> getLastSnapshot() {
ConfigSnapshot last = Iterables.getLast(snapshots, null);
return last == null ? Optional.<ConfigSnapshot>absent() : Optional.of(last);
}
public void addConfigSnapshot(final ConfigSnapshot snap, final int numberOfStoredBackups) {
if (shouldReplaceLast(numberOfStoredBackups) && !snapshots.isEmpty()) {
snapshots.remove(0);
}
snapshots.add(snap);
}
private boolean shouldReplaceLast(final int numberOfStoredBackups) {
return numberOfStoredBackups == snapshots.size();
}
}