package storm.trident.state.map;
import backtype.storm.tuple.Fields;
import backtype.storm.tuple.Values;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import storm.trident.operation.ReducerAggregator;
import storm.trident.operation.TridentCollector;
import storm.trident.operation.TridentOperationContext;
import storm.trident.state.ReducerValueUpdater;
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 MapReducerAggStateUpdater implements StateUpdater<MapState> {
ReducerAggregator _agg;
Fields _groupFields;
Fields _inputFields;
ProjectionFactory _groupFactory;
ProjectionFactory _inputFactory;
ComboList.Factory _factory;
public MapReducerAggStateUpdater(ReducerAggregator agg, Fields groupFields, Fields inputFields) {
_agg = agg;
_groupFields = groupFields;
_inputFields = inputFields;
_factory = new ComboList.Factory(groupFields.size(), 1);
}
@Override
public void updateState(MapState map, List<TridentTuple> tuples, TridentCollector collector) {
Map<List<Object>, List<TridentTuple>> grouped = new HashMap();
List<List<Object>> groups = new ArrayList<List<Object>>(tuples.size());
List<Object> values = new ArrayList<Object>(tuples.size());
for(TridentTuple t: tuples) {
List<Object> group = _groupFactory.create(t);
List<TridentTuple> groupTuples = grouped.get(group);
if(groupTuples==null) {
groupTuples = new ArrayList();
grouped.put(group, groupTuples);
}
groupTuples.add(_inputFactory.create(t));
}
List<List<Object>> uniqueGroups = new ArrayList(grouped.keySet());
List<ValueUpdater> updaters = new ArrayList(uniqueGroups.size());
for(List<Object> group: uniqueGroups) {
updaters.add(new ReducerValueUpdater(_agg, grouped.get(group)));
}
List<Object> results = map.multiUpdate(uniqueGroups, updaters);
for(int i=0; i<uniqueGroups.size(); i++) {
List<Object> group = uniqueGroups.get(i);
Object result = results.get(i);
collector.emit(_factory.create(new List[] {group, new Values(result) }));
}
}
@Override
public void prepare(Map conf, TridentOperationContext context) {
_groupFactory = context.makeProjectionFactory(_groupFields);
_inputFactory = context.makeProjectionFactory(_inputFields);
}
@Override
public void cleanup() {
}
}