/**
* 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 storm.trident.planner.processor;
import backtype.storm.task.TopologyContext;
import backtype.storm.tuple.Fields;
import java.util.List;
import java.util.Map;
import storm.trident.operation.Aggregator;
import storm.trident.operation.TridentOperationContext;
import storm.trident.planner.ProcessorContext;
import storm.trident.planner.TridentProcessor;
import storm.trident.tuple.TridentTuple;
import storm.trident.tuple.TridentTuple.Factory;
import storm.trident.tuple.TridentTupleView.ProjectionFactory;
public class AggregateProcessor implements TridentProcessor {
Aggregator _agg;
TridentContext _context;
FreshCollector _collector;
Fields _inputFields;
ProjectionFactory _projection;
public AggregateProcessor(Fields inputFields, Aggregator agg) {
_agg = agg;
_inputFields = inputFields;
}
@Override
public void prepare(Map conf, TopologyContext context, TridentContext tridentContext) {
List<Factory> parents = tridentContext.getParentTupleFactories();
if(parents.size()!=1) {
throw new RuntimeException("Aggregate operation can only have one parent");
}
_context = tridentContext;
_collector = new FreshCollector(tridentContext);
_projection = new ProjectionFactory(parents.get(0), _inputFields);
_agg.prepare(conf, new TridentOperationContext(context, _projection));
}
@Override
public void cleanup() {
_agg.cleanup();
}
@Override
public void startBatch(ProcessorContext processorContext) {
_collector.setContext(processorContext);
processorContext.state[_context.getStateIndex()] = _agg.init(processorContext.batchId, _collector);
}
@Override
public void execute(ProcessorContext processorContext, String streamId, TridentTuple tuple) {
_collector.setContext(processorContext);
_agg.aggregate(processorContext.state[_context.getStateIndex()], _projection.create(tuple), _collector);
}
@Override
public void finishBatch(ProcessorContext processorContext) {
_collector.setContext(processorContext);
_agg.complete(processorContext.state[_context.getStateIndex()], _collector);
}
@Override
public Factory getOutputFactory() {
return _collector.getOutputFactory();
}
}