hyracks-algebricks/hyracks-algebricks-tests/src/main/java/edu/uci/ics/hyracks/algebricks/tests/pushruntime/IntegerConstantEvalFactory.java

/*
 * Copyright 2009-2010 by The Regents of the University of California
 * Licensed 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 from
 * 
 *     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 edu.uci.ics.hyracks.algebricks.tests.pushruntime;

import java.io.DataOutput;
import java.io.IOException;

import edu.uci.ics.hyracks.algebricks.core.algebra.runtime.base.IEvaluator;
import edu.uci.ics.hyracks.algebricks.core.algebra.runtime.base.IEvaluatorFactory;
import edu.uci.ics.hyracks.algebricks.core.api.exceptions.AlgebricksException;
import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
import edu.uci.ics.hyracks.dataflow.common.data.accessors.ArrayBackedValueStorage;
import edu.uci.ics.hyracks.dataflow.common.data.accessors.IDataOutputProvider;
import edu.uci.ics.hyracks.dataflow.common.data.accessors.IFrameTupleReference;
import edu.uci.ics.hyracks.dataflow.common.data.marshalling.IntegerSerializerDeserializer;

public class IntegerConstantEvalFactory implements IEvaluatorFactory {

    private static final long serialVersionUID = 1L;
    private final int value;

    public IntegerConstantEvalFactory(int value) {
        this.value = value;
    }

    @Override
    public String toString() {
        return "IntConstantEvalFactory " + value;
    }

    @Override
    public IEvaluator createEvaluator(final IDataOutputProvider output) throws AlgebricksException {
        return new IEvaluator() {

            private DataOutput out = output.getDataOutput();
            private ArrayBackedValueStorage buf = new ArrayBackedValueStorage();
            boolean first = true;

            @Override
            public void evaluate(IFrameTupleReference tuple) throws AlgebricksException {
                if (first) {
                    first = false;
                    try {
                        IntegerSerializerDeserializer.INSTANCE.serialize(value, buf.getDataOutput());
                    } catch (HyracksDataException e) {
                        throw new AlgebricksException(e);
                    }
                }

                try {
                    out.write(buf.getBytes(), 0, buf.getLength());
                } catch (IOException e) {
                    throw new AlgebricksException(e);
                }
            }
        };
    }

}