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package com.salesforce.phoenix.coprocessor;

import java.io.Closeable;

import org.apache.hadoop.hbase.io.ImmutableBytesWritable;
import org.apache.hadoop.hbase.regionserver.RegionScanner;

import com.salesforce.phoenix.expression.aggregator.Aggregator;

/**
 * 
 * Interface to abstract the way in which distinct group by
 * elements are cached
 *
 * @author jtaylor
 * @since 3.0.0
 */
public interface GroupByCache extends Closeable {
    int size();
    Aggregator[] cache(ImmutableBytesWritable key);
    RegionScanner getScanner(RegionScanner s);
}
