com.ebay.pulsar.analytics.metricstore.druid.query.model.QueryCacheHelper.java Source code

Introduction

Here is the source code for com.ebay.pulsar.analytics.metricstore.druid.query.model.QueryCacheHelper.java

Source

/*******************************************************************************
*  Copyright  2012-2015 eBay Software Foundation
*  This program is dual licensed under the MIT and Apache 2.0 licenses.
*  Please see LICENSE for more information.
*******************************************************************************/

package com.ebay.pulsar.analytics.metricstore.druid.query.model;

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

import com.ebay.pulsar.analytics.metricstore.druid.aggregator.BaseAggregator;
import com.ebay.pulsar.analytics.metricstore.druid.postaggregator.BasePostAggregator;
import com.google.common.collect.Lists;

/**
 * 
 * @author rtao
 *
 */
public class QueryCacheHelper {
    private static final byte CACHE_TYPE_ID = 0x1; // used for String

    public static byte[] computeAggregatorBytes(List<BaseAggregator> aggregators) {
        List<byte[]> cacheKeySet = Lists.newArrayListWithCapacity(aggregators.size());

        int totalSize = 0;
        for (BaseAggregator agg : aggregators) {
            final byte[] cacheKey = agg.cacheKey();
            cacheKeySet.add(cacheKey);
            totalSize += cacheKey.length;
        }

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

    public static byte[] computePostAggregatorBytes(List<BasePostAggregator> postaggregators) {
        List<byte[]> cacheKeySet = Lists.newArrayListWithCapacity(postaggregators.size());

        int totalSize = 0;
        for (BasePostAggregator agg : postaggregators) {
            final byte[] cacheKey = agg.cacheKey();
            cacheKeySet.add(cacheKey);
            totalSize += cacheKey.length;
        }

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

    public static byte[] computeIntervalsBytes(List<String> intervals) {
        List<byte[]> cacheKeySet = Lists.newArrayListWithCapacity(intervals.size());

        int totalSize = 0;
        for (String interval : intervals) {
            final byte[] cacheKey = computeStringBytes(interval);
            cacheKeySet.add(cacheKey);
            totalSize += cacheKey.length;
        }

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

    private static byte[] computeStringBytes(String str) {
        byte[] stringBytes = str.getBytes();
        return ByteBuffer.allocate(1 + stringBytes.length).put(CACHE_TYPE_ID).put(stringBytes).array();
    }
}