io.druid.query.QueryCacheHelper.java Source code

Introduction

Here is the source code for io.druid.query.QueryCacheHelper.java

Source

/*
 * Druid - a distributed column store.
 * Copyright 2012 - 2015 Metamarkets Group Inc.
 *
 * Licensed 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 io.druid.query;

import com.google.common.collect.Lists;
import io.druid.query.aggregation.AggregatorFactory;

import java.nio.ByteBuffer;
import java.util.List;

/**
 */
public class QueryCacheHelper {
    public static byte[] computeAggregatorBytes(List<AggregatorFactory> aggregatorSpecs) {
        List<byte[]> cacheKeySet = Lists.newArrayListWithCapacity(aggregatorSpecs.size());

        int totalSize = 0;
        for (AggregatorFactory spec : aggregatorSpecs) {
            final byte[] cacheKey = spec.getCacheKey();
            cacheKeySet.add(cacheKey);
            totalSize += cacheKey.length;
        }

        ByteBuffer retVal = ByteBuffer.allocate(totalSize);
        for (byte[] bytes : cacheKeySet) {
            retVal.put(bytes);
        }
        return retVal.array();
    }

}