org.elasticsearch.cluster.metadata.MetaDataService Maven / Gradle / Ivy
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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.cluster.metadata;
import org.elasticsearch.cluster.routing.DjbHashFunction;
import org.elasticsearch.common.component.AbstractComponent;
import org.elasticsearch.common.inject.Inject;
import org.elasticsearch.common.math.MathUtils;
import org.elasticsearch.common.settings.Settings;
import java.util.concurrent.Semaphore;
/**
*/
public class MetaDataService extends AbstractComponent {
private final Semaphore[] indexMdLocks;
@Inject
public MetaDataService(Settings settings) {
super(settings);
indexMdLocks = new Semaphore[500];
for (int i = 0; i < indexMdLocks.length; i++) {
indexMdLocks[i] = new Semaphore(1);
}
}
public Semaphore indexMetaDataLock(String index) {
return indexMdLocks[MathUtils.mod(DjbHashFunction.DJB_HASH(index), indexMdLocks.length)];
}
}