external/storm-sqe/src/main/java/com/jwplayer/sqe/language/expression/aggregation/CreateHll.java

/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  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
 * limitations under the License.
 */
package com.jwplayer.sqe.language.expression.aggregation;

import com.jwplayer.sqe.language.expression.BaseExpression;
import com.jwplayer.sqe.language.expression.ConstantExpression;
import com.jwplayer.sqe.language.expression.ExpressionType;
import com.jwplayer.sqe.trident.aggregator.HllAggregator;
import com.jwplayer.sqe.trident.aggregator.HllCombinerAggregator;
import org.apache.storm.trident.fluent.ChainedFullAggregatorDeclarer;
import org.apache.storm.trident.fluent.ChainedPartitionAggregatorDeclarer;
import org.apache.storm.trident.fluent.GroupedStream;
import org.apache.storm.trident.state.StateFactory;
import org.apache.storm.tuple.Fields;


public class CreateHll extends AggregationExpression {
    public CreateHll() {
    }

    protected int getLog2m() {
        if(getArguments().size() == 2) {
            BaseExpression expression = getArguments().get(1);
            if(expression.getExpressionType() == ExpressionType.Constant) {
                ConstantExpression cExp = (ConstantExpression) expression;
                if(cExp.constant instanceof Number) {
                    return ((Number) cExp.constant).intValue();
                } else {
                    throw new RuntimeException(String.format("Optional 2nd argument to %s must be a number", getFunctionName()));
                }
            } else {
                throw new RuntimeException(String.format("Optional 2nd argument to %s must be a constant", getFunctionName()));
            }
        } else {
            return 11; // Default log2m
        }
    }

    @Override
    public ChainedFullAggregatorDeclarer aggregate(ChainedFullAggregatorDeclarer stream, Fields inputFields, Fields outputFields) {
        return stream.aggregate(inputFields, new HllCombinerAggregator(getLog2m()), outputFields);
    }

    @Override
    public ChainedPartitionAggregatorDeclarer partitionAggregate(ChainedPartitionAggregatorDeclarer stream, Fields inputFields, Fields outputFields) {
        return stream.partitionAggregate(inputFields, new HllAggregator(getLog2m()), outputFields);
    }

    @Override
    public void persistentAggregate(GroupedStream stream, Fields inputFields, StateFactory factory, Fields functionFields) {
        stream.persistentAggregate(factory, inputFields, new HllCombinerAggregator(getLog2m()), functionFields);
    }

    @Override
    public String getFunctionName() {
        return "createhll";
    }
}