package storm.trident.state.map;
import backtype.storm.tuple.Fields;
import backtype.storm.tuple.Values;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import storm.trident.operation.CombinerAggregator;
import storm.trident.operation.TridentCollector;
import storm.trident.operation.TridentOperationContext;
import storm.trident.state.CombinerValueUpdater;
import storm.trident.state.StateUpdater;
import storm.trident.state.ValueUpdater;
import storm.trident.tuple.ComboList;
import storm.trident.tuple.TridentTuple;
import storm.trident.tuple.TridentTupleView.ProjectionFactory;
public class MapCombinerAggStateUpdater implements StateUpdater<MapState> {
CombinerAggregator _agg;
Fields _groupFields;
Fields _inputFields;
ProjectionFactory _groupFactory;
ProjectionFactory _inputFactory;
ComboList.Factory _factory;
public MapCombinerAggStateUpdater(CombinerAggregator agg, Fields groupFields, Fields inputFields) {
_agg = agg;
_groupFields = groupFields;
_inputFields = inputFields;
if(inputFields.size()!=1) {
throw new IllegalArgumentException("Combiner aggs only take a single field as input. Got this instead: " + inputFields.toString());
}
_factory = new ComboList.Factory(groupFields.size(), inputFields.size());
}
@Override
public void updateState(MapState map, List<TridentTuple> tuples, TridentCollector collector) {
List<List<Object>> groups = new ArrayList<List<Object>>(tuples.size());
List<ValueUpdater> updaters = new ArrayList<ValueUpdater>(tuples.size());
for(TridentTuple t: tuples) {
groups.add(_groupFactory.create(t));
updaters.add(new CombinerValueUpdater(_agg,_inputFactory.create(t).getValue(0)));
}
List<Object> newVals = map.multiUpdate(groups, updaters);
for(int i=0; i<tuples.size(); i++) {
List<Object> key = groups.get(i);
Object result = newVals.get(i);
collector.emit(_factory.create(new List[] {key, new Values(result) }));
}
}
@Override
public void prepare(Map conf, TridentOperationContext context) {
_groupFactory = context.makeProjectionFactory(_groupFields);
_inputFactory = context.makeProjectionFactory(_inputFields);
}
@Override
public void cleanup() {
}
}