AggregateBuilder.java

package org.calrissian.flowbox.model.builder;

import org.calrissian.flowbox.model.AggregateOp;
import org.calrissian.flowbox.support.Aggregator;
import org.calrissian.flowbox.model.Policy;

import java.util.HashMap;
import java.util.Map;

public class AggregateBuilder extends AbstractOpBuilder {

    private Class<? extends Aggregator> aggregatorClass;
    private Policy triggerPolicy;
    private long triggerThreshold = -1;
    private Policy evictionPolicy;
    private long evictionThreshold = -1;

    private Map<String,String> config = new HashMap<String,String>();

    public AggregateBuilder(StreamBuilder flowOpsBuilder) {
        super(flowOpsBuilder);
    }

    public AggregateBuilder aggregator(Class<? extends Aggregator> aggregatorClass) {
        this.aggregatorClass = aggregatorClass;
        return this;
    }


    public AggregateBuilder config(String key, String value) {
      config.put(key, value);
      return this;
    }


    public AggregateBuilder trigger(Policy policy, long threshold) {
        this.triggerPolicy = policy;
        this.triggerThreshold = threshold;
        return this;
    }

    public AggregateBuilder evict(Policy policy, long threshold) {
        this.evictionPolicy = policy;
        this.evictionThreshold = threshold;
        return this;
    }

    public StreamBuilder end() {

        if(aggregatorClass == null)
            throw new RuntimeException("Aggregator operator needs an aggregator class");

        if(triggerPolicy == null || triggerThreshold == -1)
            throw new RuntimeException("Aggregator operator needs to have trigger policy and threshold");

        if(evictionPolicy == null || evictionThreshold == -1)
            throw new RuntimeException("Aggregator operator needs to have eviction policy and threshold");

        getStreamBuilder().addFlowOp(new AggregateOp(aggregatorClass, triggerPolicy, triggerThreshold, evictionPolicy,
                evictionThreshold, config));
        return getStreamBuilder();
    }
}