algebricks/algebricks-runtime/src/main/java/edu/uci/ics/hyracks/algebricks/runtime/writers/SerializedDataWriterFactory.java

/*
 * Copyright 2009-2013 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.runtime.writers;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.ObjectOutputStream;
import java.io.PrintStream;

import edu.uci.ics.hyracks.algebricks.common.exceptions.AlgebricksException;
import edu.uci.ics.hyracks.algebricks.data.IAWriter;
import edu.uci.ics.hyracks.algebricks.data.IAWriterFactory;
import edu.uci.ics.hyracks.algebricks.data.IPrinterFactory;
import edu.uci.ics.hyracks.api.comm.IFrameTupleAccessor;
import edu.uci.ics.hyracks.api.dataflow.value.RecordDescriptor;

public class SerializedDataWriterFactory implements IAWriterFactory {

    private static final long serialVersionUID = 1L;

    @Override
    public IAWriter createWriter(final int[] fields, final PrintStream ps, IPrinterFactory[] printerFactories,
            final RecordDescriptor inputRecordDescriptor) {
        return new IAWriter() {

            @Override
            public void init() throws AlgebricksException {
                // dump the SerializerDeserializers to disk
                try {
                    ByteArrayOutputStream baos = new ByteArrayOutputStream();
                    ObjectOutputStream oos = new ObjectOutputStream(baos);
                    oos.writeObject(inputRecordDescriptor);
                    baos.writeTo(ps);
                    oos.close();
                } catch (IOException e) {
                    throw new AlgebricksException(e);
                }
            }

            @Override
            public void printTuple(IFrameTupleAccessor tAccess, int tIdx) throws AlgebricksException {
                for (int i = 0; i < fields.length; i++) {
                    int fldStart = tAccess.getTupleStartOffset(tIdx) + tAccess.getFieldSlotsLength()
                            + tAccess.getFieldStartOffset(tIdx, fields[i]);
                    int fldLen = tAccess.getFieldLength(tIdx, fields[i]);
                    ps.write(tAccess.getBuffer().array(), fldStart, fldLen);
                }
            }
        };
    }
}