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* 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.indices.analysis;
import com.google.common.cache.CacheBuilder;
import com.google.common.cache.CacheLoader;
import com.google.common.cache.LoadingCache;
import com.google.common.util.concurrent.UncheckedExecutionException;
import org.apache.lucene.analysis.hunspell.Dictionary;
import org.elasticsearch.ElasticsearchException;
import org.elasticsearch.common.component.AbstractComponent;
import org.elasticsearch.common.inject.Inject;
import org.elasticsearch.common.io.FileSystemUtils;
import org.elasticsearch.common.settings.Settings;
import org.elasticsearch.env.Environment;
import java.io.IOException;
import java.io.InputStream;
import java.nio.file.DirectoryStream;
import java.nio.file.Files;
import java.nio.file.Path;
import java.util.*;
/**
* Serves as a node level registry for hunspell dictionaries. This services expects all dictionaries to be located under
* the {@code <path.conf>/hunspell} directory, where each locale has its dedicated sub-directory which holds the dictionary
* files. For example, the dictionary files for {@code en_US} locale must be placed under {@code <path.conf>/hunspell/en_US}
* directory.
* <p>
* The following settings can be set for each dictionary:
* <ul>
* <li>{@code ignore_case} - If true, dictionary matching will be case insensitive (defaults to {@code false})</li>
* <li>{@code strict_affix_parsing} - Determines whether errors while reading a affix rules file will cause exception or simple be ignored (defaults to {@code true})</li>
* </ul>
* <p>
* These settings can either be configured as node level configuration, such as:
* <br><br>
* <pre><code>
* indices.analysis.hunspell.dictionary.en_US.ignore_case: true
* indices.analysis.hunspell.dictionary.en_US.strict_affix_parsing: false
* </code></pre>
* <p>
* or, as dedicated configuration per dictionary, placed in a {@code settings.yml} file under the dictionary directory. For
* example, the following can be the content of the {@code <path.config>/hunspell/en_US/settings.yml} file:
* <br><br>
* <pre><code>
* ignore_case: true
* strict_affix_parsing: false
* </code></pre>
*
* @see org.elasticsearch.index.analysis.HunspellTokenFilterFactory
*/
public class HunspellService extends AbstractComponent {
public final static String HUNSPELL_LAZY_LOAD = "indices.analysis.hunspell.dictionary.lazy";
public final static String HUNSPELL_IGNORE_CASE = "indices.analysis.hunspell.dictionary.ignore_case";
private final static String OLD_HUNSPELL_LOCATION = "indices.analysis.hunspell.dictionary.location";
private final LoadingCache<String, Dictionary> dictionaries;
private final Map<String, Dictionary> knownDictionaries;
private final boolean defaultIgnoreCase;
private final Path hunspellDir;
public HunspellService(final Settings settings, final Environment env) throws IOException {
this(settings, env, Collections.<String, Dictionary>emptyMap());
}
@Inject
public HunspellService(final Settings settings, final Environment env, final Map<String, Dictionary> knownDictionaries) throws IOException {
super(settings);
this.knownDictionaries = knownDictionaries;
this.hunspellDir = resolveHunspellDirectory(settings, env);
this.defaultIgnoreCase = settings.getAsBoolean(HUNSPELL_IGNORE_CASE, false);
dictionaries = CacheBuilder.newBuilder().build(new CacheLoader<String, Dictionary>() {
@Override
public Dictionary load(String locale) throws Exception {
Dictionary dictionary = knownDictionaries.get(locale);
if (dictionary == null) {
dictionary = loadDictionary(locale, settings, env);
}
return dictionary;
}
});
if (!settings.getAsBoolean(HUNSPELL_LAZY_LOAD, false)) {
scanAndLoadDictionaries();
}
}
/**
* Returns the hunspell dictionary for the given locale.
*
* @param locale The name of the locale
*/
public Dictionary getDictionary(String locale) {
return dictionaries.getUnchecked(locale);
}
private Path resolveHunspellDirectory(Settings settings, Environment env) {
String location = settings.get(OLD_HUNSPELL_LOCATION, null);
if (location != null) {
throw new IllegalArgumentException("please, put your hunspell dictionaries under config/hunspell !");
}
return env.configFile().resolve("hunspell");
}
/**
* Scans the hunspell directory and loads all found dictionaries
*/
private void scanAndLoadDictionaries() throws IOException {
if (Files.isDirectory(hunspellDir)) {
try (DirectoryStream<Path> stream = Files.newDirectoryStream(hunspellDir)) {
for (Path file : stream) {
if (Files.isDirectory(file)) {
try (DirectoryStream<Path> inner = Files.newDirectoryStream(hunspellDir.resolve(file), "*.dic")) {
if (inner.iterator().hasNext()) { // just making sure it's indeed a dictionary dir
try {
dictionaries.getUnchecked(file.getFileName().toString());
} catch (UncheckedExecutionException e) {
// The cache loader throws unchecked exception (see #loadDictionary()),
// here we simply report the exception and continue loading the dictionaries
logger.error("exception while loading dictionary {}", file.getFileName(), e);
}
}
}
}
}
}
}
}
/**
* Loads the hunspell dictionary for the given local.
*
* @param locale The locale of the hunspell dictionary to be loaded.
* @param nodeSettings The node level settings
* @param env The node environment (from which the conf path will be resolved)
* @return The loaded Hunspell dictionary
* @throws Exception when loading fails (due to IO errors or malformed dictionary files)
*/
private Dictionary loadDictionary(String locale, Settings nodeSettings, Environment env) throws Exception {
if (logger.isDebugEnabled()) {
logger.debug("Loading hunspell dictionary [{}]...", locale);
}
Path dicDir = hunspellDir.resolve(locale);
if (FileSystemUtils.isAccessibleDirectory(dicDir, logger) == false) {
throw new ElasticsearchException(String.format(Locale.ROOT, "Could not find hunspell dictionary [%s]", locale));
}
// merging node settings with hunspell dictionary specific settings
nodeSettings = loadDictionarySettings(dicDir, nodeSettings.getByPrefix("indices.analysis.hunspell.dictionary." + locale + "."));
boolean ignoreCase = nodeSettings.getAsBoolean("ignore_case", defaultIgnoreCase);
Path[] affixFiles = FileSystemUtils.files(dicDir, "*.aff");
if (affixFiles.length == 0) {
throw new ElasticsearchException(String.format(Locale.ROOT, "Missing affix file for hunspell dictionary [%s]", locale));
}
if (affixFiles.length != 1) {
throw new ElasticsearchException(String.format(Locale.ROOT, "Too many affix files exist for hunspell dictionary [%s]", locale));
}
InputStream affixStream = null;
Path[] dicFiles = FileSystemUtils.files(dicDir, "*.dic");
List<InputStream> dicStreams = new ArrayList<>(dicFiles.length);
try {
for (int i = 0; i < dicFiles.length; i++) {
dicStreams.add(Files.newInputStream(dicFiles[i]));
}
affixStream = Files.newInputStream(affixFiles[0]);
return new Dictionary(affixStream, dicStreams, ignoreCase);
} catch (Exception e) {
logger.error("Could not load hunspell dictionary [{}]", e, locale);
throw e;
} finally {
if (affixStream != null) {
try {
affixStream.close();
} catch (IOException e) {
// nothing much we can do here
}
}
for (InputStream in : dicStreams) {
if (in != null) {
try {
in.close();
} catch (IOException e) {
// nothing much we can do here
}
}
}
}
}
/**
* Each hunspell dictionary directory may contain a {@code settings.yml} which holds dictionary specific settings. Default
* values for these settings are defined in the given default settings.
*
* @param dir The directory of the dictionary
* @param defaults The default settings for this dictionary
* @return The resolved settings.
*/
private static Settings loadDictionarySettings(Path dir, Settings defaults) {
Path file = dir.resolve("settings.yml");
if (Files.exists(file)) {
return Settings.settingsBuilder().loadFromPath(file).put(defaults).build();
}
file = dir.resolve("settings.json");
if (Files.exists(file)) {
return Settings.settingsBuilder().loadFromPath(file).put(defaults).build();
}
return defaults;
}
}