/*
* 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.index.aliases;
import org.apache.lucene.search.BooleanClause;
import org.apache.lucene.search.Filter;
import org.apache.lucene.search.FilterClause;
import org.elasticsearch.common.Nullable;
import org.elasticsearch.common.collect.ImmutableMap;
import org.elasticsearch.common.collect.UnmodifiableIterator;
import org.elasticsearch.common.compress.CompressedString;
import org.elasticsearch.common.inject.Inject;
import org.elasticsearch.common.lucene.search.XBooleanFilter;
import org.elasticsearch.common.settings.Settings;
import org.elasticsearch.common.xcontent.XContentFactory;
import org.elasticsearch.common.xcontent.XContentParser;
import org.elasticsearch.index.AbstractIndexComponent;
import org.elasticsearch.index.Index;
import org.elasticsearch.index.query.IndexQueryParserService;
import org.elasticsearch.index.settings.IndexSettings;
import org.elasticsearch.indices.AliasFilterParsingException;
import org.elasticsearch.indices.InvalidAliasNameException;
import java.io.IOException;
import static org.elasticsearch.common.collect.MapBuilder.*;
/**
* @author imotov
*/
public class IndexAliasesService extends AbstractIndexComponent implements Iterable<IndexAlias> {
private final IndexQueryParserService indexQueryParser;
private volatile ImmutableMap<String, IndexAlias> aliases = ImmutableMap.of();
private final Object mutex = new Object();
@Inject public IndexAliasesService(Index index, @IndexSettings Settings indexSettings, IndexQueryParserService indexQueryParser) {
super(index, indexSettings);
this.indexQueryParser = indexQueryParser;
}
public boolean hasAlias(String alias) {
return aliases.containsKey(alias);
}
public IndexAlias alias(String alias) {
return aliases.get(alias);
}
public void add(String alias, @Nullable CompressedString filter) {
add(new IndexAlias(alias, filter, parse(alias, filter)));
}
/**
* Returns the filter associated with listed filtering aliases.
*
* <p>The list of filtering aliases should be obtained by calling MetaData.filteringAliases.
* Returns <tt>null</tt> if no filtering is required.</p>
*/
public Filter aliasFilter(String... aliases) {
if (aliases == null || aliases.length == 0) {
return null;
}
if (aliases.length == 1) {
IndexAlias indexAlias = alias(aliases[0]);
if (indexAlias == null) {
// This shouldn't happen unless alias disappeared after filteringAliases was called.
throw new InvalidAliasNameException(index, aliases[0], "Unknown alias name was passed to alias Filter");
}
return indexAlias.parsedFilter();
} else {
// we need to bench here a bit, to see maybe it makes sense to use OrFilter
XBooleanFilter combined = new XBooleanFilter();
for (String alias : aliases) {
IndexAlias indexAlias = alias(alias);
if (indexAlias == null) {
// This shouldn't happen unless alias disappeared after filteringAliases was called.
throw new InvalidAliasNameException(index, aliases[0], "Unknown alias name was passed to alias Filter");
}
if (indexAlias.parsedFilter() != null) {
combined.add(new FilterClause(indexAlias.parsedFilter(), BooleanClause.Occur.SHOULD));
} else {
// The filter might be null only if filter was removed after filteringAliases was called
return null;
}
}
if (combined.getShouldFilters().size() == 0) {
return null;
}
if (combined.getShouldFilters().size() == 1) {
return combined.getShouldFilters().get(0);
}
return combined;
}
}
private void add(IndexAlias indexAlias) {
synchronized (mutex) {
aliases = newMapBuilder(aliases).put(indexAlias.alias(), indexAlias).immutableMap();
}
}
public void remove(String alias) {
synchronized (mutex) {
aliases = newMapBuilder(aliases).remove(alias).immutableMap();
}
}
private Filter parse(String alias, CompressedString filter) {
if (filter == null) {
return null;
}
try {
byte[] filterSource = filter.uncompressed();
XContentParser parser = XContentFactory.xContent(filterSource).createParser(filterSource);
try {
return indexQueryParser.parseInnerFilter(parser);
} finally {
parser.close();
}
} catch (IOException ex) {
throw new AliasFilterParsingException(index, alias, "Invalid alias filter", ex);
}
}
@Override public UnmodifiableIterator<IndexAlias> iterator() {
return aliases.values().iterator();
}
}