content: /*
   * 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 com.manning.hip.ch3.seqfile;
  
  import com.manning.hip.ch3.StockPriceWritable;
  import org.apache.hadoop.io.Text;
  import org.apache.hadoop.mapreduce.InputFormat;
  import org.apache.hadoop.mapreduce.Job;
  import org.apache.hadoop.mapreduce.RecordReader;
  import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
  import org.apache.hadoop.mapreduce.lib.input.SequenceFileInputFormat;
  import org.apache.hadoop.mapreduce.lib.input.SequenceFileRecordReader;
  import org.apache.pig.FileInputLoadFunc;
  import org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.PigSplit;
  import org.apache.pig.data.Tuple;
  import org.apache.pig.data.TupleFactory;
  
  import java.io.IOException;
  import java.util.Arrays;
  
  public class SequenceFileStockLoader extends FileInputLoadFunc {
  
    private SequenceFileRecordReader<Text, StockPriceWritable> reader;
  
    @Override
    public Tuple getNext() throws IOException {
      boolean next;
      try {
        next = reader.nextKeyValue();
      } catch (InterruptedException e) {
        throw new IOException(e);
      }
  
      if (!next) return null;
  
      Object value = reader.getCurrentValue();
  
      if (value == null) {
        return null;
      }
      if (!(value instanceof StockPriceWritable)) {
        return null;
      }
      StockPriceWritable w = (StockPriceWritable) value;
  
      return TupleFactory.getInstance().newTuple(Arrays.asList(
          w.getSymbol(), w.getDate(), w.getOpen(),
          w.getHigh(), w.getLow(), w.getClose(),
          w.getVolume(), w.getAdjClose()
      ));
    }
  
    @SuppressWarnings("unchecked")
    @Override
    public InputFormat getInputFormat() throws IOException {
      return new SequenceFileInputFormat<Text, StockPriceWritable>();
    }
  
    @SuppressWarnings("unchecked")
    @Override
    public void prepareToRead(RecordReader reader, PigSplit split)
        throws IOException {
      this.reader = (SequenceFileRecordReader) reader;
    }
  
    @Override
    public void setLocation(String location, Job job)
        throws IOException {
      FileInputFormat.setInputPaths(job, location);
    }
  }
  