/*
*
* * Licensed to the Apache Software Foundation (ASF) under one or more
* * contributor license agreements. The ASF 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
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* * copyright in this work, please see the NOTICE file in the top level
* * directory of this distribution.
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*/
package org.apache.usergrid.corepersistence.index;
import com.google.common.hash.Funnel;
import com.google.inject.Inject;
import com.google.inject.Singleton;
import org.apache.usergrid.persistence.core.scope.ApplicationScope;
import org.apache.usergrid.persistence.core.shard.ExpandingShardLocator;
import org.apache.usergrid.persistence.core.shard.StringHashUtils;
/**
* Strategy for getting index buckets, needs to be held in memory
*/
@Singleton
public class ApplicationIndexBucketLocator{
/**
* Number of buckets to hash across.
*/
private final int numberOfBuckets ;
/**
* How to funnel keys for buckets
*/
private final Funnel<String> mapKeyFunnel;
/**
* Locator to get us all buckets
*/
private final ExpandingShardLocator<String> bucketLocator ;
/**
* Startseed for buckets
*/
private final int indexBucketOffset;
@Inject
public ApplicationIndexBucketLocator(CoreIndexFig indexFig){
numberOfBuckets = indexFig.getNumberOfIndexBuckets();
mapKeyFunnel = (key, into) -> into.putString( key, StringHashUtils.UTF8 );
indexBucketOffset = indexFig.getBucketOffset();
bucketLocator = new ExpandingShardLocator<>(mapKeyFunnel, numberOfBuckets);
}
public int getBucket(ApplicationScope applicationScope){
//potentially add offset to remove old buckets
//if set is 1-5 then +5 would change range to 6-10
return indexBucketOffset + bucketLocator.getCurrentBucket(applicationScope.getApplication().getUuid().toString());
}
}