java/pig-galago/src/com/yahoo/pig/impl/physicalLayer/PhysicalOperator.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.io.Serializable;
   9
  10 import com.yahoo.pig.data.Tuple;
  11 import com.yahoo.pig.impl.logicalLayer.LogicalOperator;
  12
  13 abstract public class PhysicalOperator implements Serializable {
  14
  15     public PhysicalOperator[] inputs = null;
  16     int outputType;
  17
  18     /**
  19      *
  20      * This constructor should go away when we eventually implement CQ even for the mapreduce exec type
  21      */
  22     public PhysicalOperator(){
  23         outputType = LogicalOperator.FIXED;
  24     }
  25
  26
  27     public PhysicalOperator(int outputType){
  28         this.outputType = outputType;
  29     }
  30
  31     public boolean open(boolean continueFromLast) throws IOException {
  32         // call open() on all inputs
  33         if (inputs != null) {
  34             for (int i = 0; i < inputs.length; i++) {
  35                 if (!inputs[i].open(continueFromLast))
  36                     return false;
  37             }
  38         }
  39         return true;
  40     }
  41
  42     abstract public Tuple getNext() throws IOException;
  43
  44     public void close() throws IOException {
  45         // call close() on all inputs
  46         if (inputs != null)
  47             for (int i = 0; i < inputs.length; i++)
  48                 inputs[i].close();
  49     }
  50
  51     public int getOutputType(){
  52         return outputType;
  53     }
  54 }