TfIdfUpdater.java

package storm.cookbook.tfidf.state;

import java.util.ArrayList;
import java.util.LinkedList;
import java.util.List;

import backtype.storm.tuple.Values;
import storm.trident.operation.TridentCollector;
import storm.trident.state.BaseStateUpdater;
import storm.trident.state.map.SnapshottableMap;
import storm.trident.tuple.TridentTuple;

@SuppressWarnings("rawtypes")
public class TfIdfUpdater extends BaseStateUpdater<SnapshottableMap> {

	private static final long serialVersionUID = 1L;

	@SuppressWarnings({ "unchecked" })
	public void updateState(SnapshottableMap state, List<TridentTuple> tuples, TridentCollector collector) {
		List<List<Object>> keys = new LinkedList<List<Object>>();
		List<List<Object>> values = new LinkedList<List<Object>>();

		for (TridentTuple tuple : tuples) {
			List<Object> k = new ArrayList<Object>();
			List<Object> v = new ArrayList<Object>();
			k.add(tuple.getValueByField("documentId"));
			k.add(tuple.getValueByField("term"));
			v.add(tuple.getValueByField("tfidf"));
			keys.add(k);
			values.add(v);
		}
		state.multiPut(keys, values);

		for (TridentTuple tuple : tuples) {
			collector.emit(new Values(tuple.getValueByField("documentId"), tuple.getValueByField("term"),
					tuple.getValueByField("tfidf")));
		}

	}

}