org.elasticsearch.ingest.geoip.DatabaseReaderLazyLoader Maven / Gradle / Ivy
/*
* Licensed to Elasticsearch under one or more contributor
* license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright
* ownership. Elasticsearch 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.ingest.geoip;
import com.maxmind.geoip2.DatabaseReader;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.apache.lucene.util.SetOnce;
import org.elasticsearch.common.CheckedSupplier;
import org.elasticsearch.core.internal.io.IOUtils;
import java.io.Closeable;
import java.io.IOException;
import java.io.InputStream;
import java.nio.charset.StandardCharsets;
import java.nio.file.Files;
import java.nio.file.Path;
import java.util.Objects;
/**
* Facilitates lazy loading of the database reader, so that when the geoip plugin is installed, but not used,
* no memory is being wasted on the database reader.
*/
class DatabaseReaderLazyLoader implements Closeable {
private static final Logger LOGGER = LogManager.getLogger(DatabaseReaderLazyLoader.class);
private final Path databasePath;
private final CheckedSupplier loader;
final SetOnce databaseReader;
// cache the database type so that we do not re-read it on every pipeline execution
final SetOnce databaseType;
DatabaseReaderLazyLoader(final Path databasePath, final CheckedSupplier loader) {
this.databasePath = Objects.requireNonNull(databasePath);
this.loader = Objects.requireNonNull(loader);
this.databaseReader = new SetOnce<>();
this.databaseType = new SetOnce<>();
}
/**
* Read the database type from the database. We do this manually instead of relying on the built-in mechanism to avoid reading the
* entire database into memory merely to read the type. This is especially important to maintain on master nodes where pipelines are
* validated. If we read the entire database into memory, we could potentially run into low-memory constraints on such nodes where
* loading this data would otherwise be wasteful if they are not also ingest nodes.
*
* @return the database type
* @throws IOException if an I/O exception occurs reading the database type
*/
final String getDatabaseType() throws IOException {
if (databaseType.get() == null) {
synchronized (databaseType) {
if (databaseType.get() == null) {
final long fileSize = databaseFileSize();
if (fileSize <= 512) {
throw new IOException("unexpected file length [" + fileSize + "] for [" + databasePath + "]");
}
final int[] databaseTypeMarker = {'d', 'a', 't', 'a', 'b', 'a', 's', 'e', '_', 't', 'y', 'p', 'e'};
try (InputStream in = databaseInputStream()) {
// read the last 512 bytes
final long skipped = in.skip(fileSize - 512);
if (skipped != fileSize - 512) {
throw new IOException("failed to skip [" + (fileSize - 512) + "] bytes while reading [" + databasePath + "]");
}
final byte[] tail = new byte[512];
int read = 0;
do {
final int actualBytesRead = in.read(tail, read, 512 - read);
if (actualBytesRead == -1) {
throw new IOException("unexpected end of stream [" + databasePath + "] after reading [" + read + "] bytes");
}
read += actualBytesRead;
} while (read != 512);
// find the database_type header
int metadataOffset = -1;
int markerOffset = 0;
for (int i = 0; i < tail.length; i++) {
byte b = tail[i];
if (b == databaseTypeMarker[markerOffset]) {
markerOffset++;
} else {
markerOffset = 0;
}
if (markerOffset == databaseTypeMarker.length) {
metadataOffset = i + 1;
break;
}
}
if (metadataOffset == -1) {
throw new IOException("database type marker not found");
}
// read the database type
final int offsetByte = tail[metadataOffset] & 0xFF;
final int type = offsetByte >>> 5;
if (type != 2) {
throw new IOException("type must be UTF-8 string");
}
int size = offsetByte & 0x1f;
databaseType.set(new String(tail, metadataOffset + 1, size, StandardCharsets.UTF_8));
}
}
}
}
return databaseType.get();
}
long databaseFileSize() throws IOException {
return Files.size(databasePath);
}
InputStream databaseInputStream() throws IOException {
return Files.newInputStream(databasePath);
}
DatabaseReader get() throws IOException {
if (databaseReader.get() == null) {
synchronized (databaseReader) {
if (databaseReader.get() == null) {
databaseReader.set(loader.get());
LOGGER.debug("loaded [{}] geo-IP database", databasePath);
}
}
}
return databaseReader.get();
}
@Override
public synchronized void close() throws IOException {
IOUtils.close(databaseReader.get());
}
}