java/pig-galago/src/com/yahoo/pig/impl/physicalLayer/PORead.java

   1 /*
   2  * Copyright (c) 2007 Yahoo! Inc.  All rights reserved.
   3  * See accompanying LICENSE file.
   4  */
   5 package com.yahoo.pig.impl.physicalLayer;
   6
   7 import java.io.IOException;
   8 import java.util.Iterator;
   9
  10 import com.yahoo.pig.data.DataBag;
  11 import com.yahoo.pig.data.Tuple;
  12
  13 public class PORead extends PhysicalOperator {
  14     DataBag             bag;
  15     Iterator<Tuple> it;
  16
  17     public PORead(DataBag bagIn, int outputType) {
  18         super(outputType);
  19         inputs = new PhysicalOperator[0];
  20
  21         bag = bagIn;
  22
  23         it = null;
  24     }
  25
  26     public boolean open(boolean continueFromLast) throws IOException {
  27         if (continueFromLast){
  28                 throw new RuntimeException("LOReads should not occur in continuous plans");
  29         }
  30         it = bag.content();
  31
  32         return true;
  33     }
  34
  35     public Tuple getNext() throws IOException {
  36         if (it.hasNext())
  37             return it.next();
  38         else
  39             return null;
  40     }
  41
  42 }