/**
* 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.ArrayList;
import java.util.List;
import java.util.Map;
import storm.trident.operation.TridentOperationContext;
import storm.trident.planner.ProcessorContext;
import storm.trident.planner.TridentProcessor;
import storm.trident.state.QueryFunction;
import storm.trident.state.State;
import storm.trident.tuple.TridentTuple;
import storm.trident.tuple.TridentTuple.Factory;
import storm.trident.tuple.TridentTupleView.ProjectionFactory;
public class StateQueryProcessor implements TridentProcessor {
QueryFunction _function;
State _state;
String _stateId;
TridentContext _context;
Fields _inputFields;
ProjectionFactory _projection;
AppendCollector _collector;
public StateQueryProcessor(String stateId, Fields inputFields, QueryFunction function) {
_stateId = stateId;
_function = function;
_inputFields = inputFields;
}
@Override
public void prepare(Map conf, TopologyContext context, TridentContext tridentContext) {
List<Factory> parents = tridentContext.getParentTupleFactories();
if(parents.size()!=1) {
throw new RuntimeException("State query operation can only have one parent");
}
_context = tridentContext;
_state = (State) context.getTaskData(_stateId);
_projection = new ProjectionFactory(parents.get(0), _inputFields);
_collector = new AppendCollector(tridentContext);
_function.prepare(conf, new TridentOperationContext(context, _projection));
}
@Override
public void cleanup() {
_function.cleanup();
}
@Override
public void startBatch(ProcessorContext processorContext) {
processorContext.state[_context.getStateIndex()] = new BatchState();
}
@Override
public void execute(ProcessorContext processorContext, String streamId, TridentTuple tuple) {
BatchState state = (BatchState) processorContext.state[_context.getStateIndex()];
state.tuples.add(tuple);
state.args.add(_projection.create(tuple));
}
@Override
public void finishBatch(ProcessorContext processorContext) {
BatchState state = (BatchState) processorContext.state[_context.getStateIndex()];
if(!state.tuples.isEmpty()) {
List<Object> results = _function.batchRetrieve(_state, state.args);
if(results.size()!=state.tuples.size()) {
throw new RuntimeException("Results size is different than argument size: " + results.size() + " vs " + state.tuples.size());
}
for(int i=0; i<state.tuples.size(); i++) {
TridentTuple tuple = state.tuples.get(i);
Object result = results.get(i);
_collector.setContext(processorContext, tuple);
_function.execute(_projection.create(tuple), result, _collector);
}
}
}
private static class BatchState {
public List<TridentTuple> tuples = new ArrayList<TridentTuple>();
public List<TridentTuple> args = new ArrayList<TridentTuple>();
}
@Override
public Factory getOutputFactory() {
return _collector.getOutputFactory();
}
}