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Open Source, Distributed, RESTful Search Engine
/*
* Licensed to Elastic Search and Shay Banon under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. Elastic Search licenses this
* file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
package org.elasticsearch.gateway.fs;
import org.elasticsearch.ElasticSearchException;
import org.elasticsearch.cluster.ClusterName;
import org.elasticsearch.cluster.metadata.MetaData;
import org.elasticsearch.env.Environment;
import org.elasticsearch.gateway.Gateway;
import org.elasticsearch.gateway.GatewayException;
import org.elasticsearch.index.gateway.fs.FsIndexGatewayModule;
import org.elasticsearch.util.component.AbstractLifecycleComponent;
import org.elasticsearch.util.inject.Inject;
import org.elasticsearch.util.inject.Module;
import org.elasticsearch.util.io.FileSystemUtils;
import org.elasticsearch.util.settings.Settings;
import org.elasticsearch.util.xcontent.ToXContent;
import org.elasticsearch.util.xcontent.XContentFactory;
import org.elasticsearch.util.xcontent.XContentParser;
import org.elasticsearch.util.xcontent.XContentType;
import org.elasticsearch.util.xcontent.builder.BinaryXContentBuilder;
import java.io.*;
import static org.elasticsearch.util.io.FileSystemUtils.*;
/**
* @author kimchy (shay.banon)
*/
public class FsGateway extends AbstractLifecycleComponent implements Gateway {
private final Environment environment;
private final ClusterName clusterName;
private final String location;
private final File gatewayHome;
private volatile int currentIndex;
@Inject public FsGateway(Settings settings, Environment environment, ClusterName clusterName) throws IOException {
super(settings);
this.clusterName = clusterName;
this.environment = environment;
this.location = componentSettings.get("location");
this.gatewayHome = createGatewayHome(location, environment, clusterName);
if (!gatewayHome.exists()) {
throw new IOException("FsGateway location [" + gatewayHome + "] can't be created");
}
this.currentIndex = findLatestIndex(gatewayHome);
logger.debug("Latest metadata found at index [" + currentIndex + "]");
}
@Override protected void doStart() throws ElasticSearchException {
}
@Override protected void doStop() throws ElasticSearchException {
}
@Override protected void doClose() throws ElasticSearchException {
}
public File gatewayHome() {
return gatewayHome;
}
private static File createGatewayHome(String location, Environment environment, ClusterName clusterName) {
File f;
if (location != null) {
// if its a custom location, append the cluster name to it just so we have unique
// in case two clusters point to the same location
f = new File(new File(location), clusterName.value());
} else {
// work already includes the cluster name
f = new File(environment.workWithClusterFile(), "gateway");
}
if (f.exists() && f.isDirectory()) {
return f;
}
boolean result;
for (int i = 0; i < 5; i++) {
result = f.mkdirs();
if (result) {
break;
}
}
return f;
}
@Override public void write(MetaData metaData) throws GatewayException {
try {
final File file = new File(gatewayHome, "metadata-" + (currentIndex + 1));
for (int i = 0; i < 5; i++) {
if (file.createNewFile())
break;
}
if (!file.exists()) {
throw new GatewayException("Failed to create new file [" + file + "]");
}
BinaryXContentBuilder builder = XContentFactory.contentBinaryBuilder(XContentType.JSON);
builder.prettyPrint();
builder.startObject();
MetaData.Builder.toXContent(metaData, builder, ToXContent.EMPTY_PARAMS);
builder.endObject();
FileOutputStream fileStream = new FileOutputStream(file);
fileStream.write(builder.unsafeBytes(), 0, builder.unsafeBytesLength());
fileStream.close();
syncFile(file);
currentIndex++;
//delete old files.
File[] oldFiles = gatewayHome.listFiles(new FilenameFilter() {
@Override public boolean accept(File dir, String name) {
return name.startsWith("metadata-") && !name.equals(file.getName());
}
});
for (File oldFile : oldFiles) {
oldFile.delete();
}
} catch (IOException e) {
throw new GatewayException("can't write new metadata file into the gateway", e);
}
}
@Override public MetaData read() throws GatewayException {
try {
if (currentIndex == -1)
return null;
File file = new File(gatewayHome, "metadata-" + currentIndex);
if (!file.exists()) {
throw new GatewayException("can't find current metadata file");
}
return readMetaData(file);
} catch (GatewayException e) {
throw e;
} catch (Exception e) {
throw new GatewayException("can't read metadata file from the gateway", e);
}
}
@Override public Class suggestIndexGateway() {
return FsIndexGatewayModule.class;
}
@Override public void reset() {
FileSystemUtils.deleteRecursively(gatewayHome, false);
currentIndex = -1;
}
private int findLatestIndex(File gatewayHome) {
File[] files = gatewayHome.listFiles(new FilenameFilter() {
@Override public boolean accept(File dir, String name) {
return name.startsWith("metadata-");
}
});
int index = -1;
for (File file : files) {
if (logger.isTraceEnabled()) {
logger.trace("[findLatestMetadata]: Processing file [" + file + "]");
}
String name = file.getName();
int fileIndex = Integer.parseInt(name.substring(name.indexOf('-') + 1));
if (fileIndex >= index) {
// try and read the meta data
try {
readMetaData(file);
index = fileIndex;
} catch (IOException e) {
logger.warn("[findLatestMetadata]: Failed to read metadata from [" + file + "], ignoring...", e);
}
}
}
return index;
}
private MetaData readMetaData(File file) throws IOException {
FileInputStream fileStream = new FileInputStream(file);
XContentParser parser = null;
try {
parser = XContentFactory.xContent(XContentType.JSON).createParser(fileStream);
return MetaData.Builder.fromXContent(parser, settings);
} finally {
if (parser != null) {
parser.close();
}
try {
fileStream.close();
} catch (Exception e) {
// ignore
}
}
}
}