fr.inria.oak.paxquery.pact.operators.unary.NestedAggregationOperator.java Source code

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/*******************************************************************************
 * Copyright (C) 2013, 2014, 2015 by Inria and Paris-Sud University
 * 
 * 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 fr.inria.oak.paxquery.pact.operators.unary;

import javax.xml.bind.DatatypeConverter;

import org.apache.commons.lang.SerializationUtils;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.flink.configuration.Configuration;
import org.apache.flink.types.IntValue;
import org.apache.flink.types.Record;
import org.apache.flink.types.StringValue;
import org.apache.flink.util.Collector;

import fr.inria.oak.paxquery.common.aggregation.AggregationType;
import fr.inria.oak.paxquery.common.datamodel.metadata.NestedMetadata;
import fr.inria.oak.paxquery.pact.configuration.PACTOperatorsConfiguration;
import fr.inria.oak.paxquery.pact.datamodel.type.RecordList;
import fr.inria.oak.paxquery.pact.operations.aggregation.BaseAggregationOperation;
import fr.inria.oak.paxquery.pact.operations.aggregation.Count;
import fr.inria.oak.paxquery.pact.operations.aggregation.Max;
import fr.inria.oak.paxquery.pact.operations.aggregation.Min;
import fr.inria.oak.paxquery.pact.operations.aggregation.Sum;
import fr.inria.oak.paxquery.pact.operators.BaseMapOperator;

/**
 * Aggregation operator in PACT. It works over field of records that belong to a nested collection.
 * 
 */
public class NestedAggregationOperator extends BaseMapOperator {

    private static final Log logger = LogFactory.getLog(NestedAggregationOperator.class);

    private int[] aggregationPath;

    private AggregationType aggregationType;

    private boolean attachDummyColumn;

    @Override
    public void open(Configuration parameters) throws Exception {
        super.open(parameters);

        String aggregationPathEncoded = parameters
                .getString(PACTOperatorsConfiguration.AGGREGATION_PATH_BINARY.toString(), null);
        byte[] aggregationPathBytes = DatatypeConverter.parseBase64Binary(aggregationPathEncoded);
        final int[] aggregationPath = (int[]) SerializationUtils.deserialize(aggregationPathBytes);
        this.aggregationPath = aggregationPath;

        String aggregationTypeEncoded = parameters
                .getString(PACTOperatorsConfiguration.AGGREGATION_TYPE_BINARY.toString(), null);
        byte[] aggregationTypeBytes = DatatypeConverter.parseBase64Binary(aggregationTypeEncoded);
        final AggregationType aggregationType = (AggregationType) SerializationUtils
                .deserialize(aggregationTypeBytes);
        this.aggregationType = aggregationType;

        this.attachDummyColumn = parameters
                .getBoolean(PACTOperatorsConfiguration.ATTACH_DUMMY_COLUMN_BOOLEAN.toString(), false);

    }

    @Override
    public void map(Record record, Collector<Record> collector)
            throws InstantiationException, IllegalAccessException {
        nestedAggregation(this.inputRecordsSignature, record, this.aggregationPath, this.aggregationType,
                this.attachDummyColumn, collector);
    }

    /**
     * @param inputRecordsSignature
     * @param record
     * @param aggregationPath
     * @param aggregationType
     * @param collector
     */
    public static void nestedAggregation(NestedMetadata inputRecordsSignature, Record record, int[] aggregationPath,
            AggregationType aggregationType, boolean attachDummyColumn, Collector<Record> collector) {
        nestedAggregationRec(inputRecordsSignature, record, aggregationPath, 0, aggregationType, attachDummyColumn,
                collector);

        collector.collect(record);
    }

    private static void nestedAggregationRec(NestedMetadata inputRecordsSignature, Record record,
            int[] aggregationPath, int pos, AggregationType aggregationType, boolean attachDummyColumn,
            Collector<Record> collector) {
        if (pos != aggregationPath.length - 2) {
            RecordList list = record.getField(aggregationPath[pos++], RecordList.class);
            for (Record nestedRecord : list)
                nestedAggregationRec(inputRecordsSignature, nestedRecord, aggregationPath, pos, aggregationType,
                        attachDummyColumn, collector);
        } else {
            BaseAggregationOperation operation;
            switch (aggregationType) {
            case COUNT:
                operation = new Count();
                break;
            case MAX:
                operation = new Max(inputRecordsSignature.getNestedType(aggregationPath));
                break;
            case MIN:
                operation = new Min(inputRecordsSignature.getNestedType(aggregationPath));
                break;
            case SUM:
                operation = new Sum(inputRecordsSignature.getNestedType(aggregationPath));
                break;
            default:
                logger.error("Aggregation type not supported!");
                return;
            }

            // For each record, we aggregate the proper value and we add it to the list
            RecordList list = record.getField(aggregationPath[pos++], RecordList.class);
            for (Record nestedRecord : list)
                operation.aggregate(nestedRecord.getField(aggregationPath[pos], StringValue.class));
            record.addField(operation.returnResult());
            if (attachDummyColumn)
                record.addField(new IntValue(1));
        }

    }

}