java/pig-galago/src/com/yahoo/pig/impl/eval/ColEvalItem.java

   1 /*
   2  * Copyright (c) 2007 Yahoo! Inc.  All rights reserved.
   3  * See accompanying LICENSE file.
   4  */
   5 package com.yahoo.pig.impl.eval;
   6
   7 import java.io.IOException;
   8 import java.util.*;
   9
  10 import com.yahoo.pig.data.*;
  11 import com.yahoo.pig.impl.PigContext;
  12 import com.yahoo.pig.impl.logicalLayer.schema.SchemaItem;
  13 import com.yahoo.pig.impl.logicalLayer.schema.SchemaItemList;
  14
  15
  16 final public class ColEvalItem extends NestableEvalItem {
  17     public String alias = null;
  18     public int colNum = -1;
  19
  20     public ColEvalItem(PigContext pigContext, int colNum) {
  21         super(pigContext);
  22         this.colNum = colNum;
  23     }
  24
  25     public ColEvalItem(PigContext pigContext, String alias) {
  26         super(pigContext);
  27         this.alias = alias;
  28     }
  29
  30     public String toString() {
  31         StringBuffer sb = new StringBuffer();
  32         if (colNum != -1) sb.append("$" + colNum);
  33         else sb.append(alias);
  34         if (nestedEval != null) sb.append(nestedEval);
  35
  36         if (subColSpec != null) sb.append(".(" + subColSpec + ")");
  37
  38         return sb.toString();
  39     }
  40
  41     public List<String> getFuncs() {
  42         List<String> funcs = new ArrayList<String>();
  43
  44         if (nestedEval != null) funcs.addAll(nestedEval.getFuncs());
  45
  46         if (subColSpec != null) funcs.addAll(subColSpec.getFuncs());
  47
  48         return funcs;
  49     }
  50
  51     public String stringVal(Tuple tup) throws IOException {
  52         return tup.getAtomField(colNum).strval();
  53     }
  54
  55
  56     @Override
  57     public Double doubleVal(Tuple tup) throws IOException {
  58         return tup.getAtomField(colNum).numval();
  59     }
  60
  61
  62     @Override
  63     public SchemaItem mapInputSchemaInitial(SchemaItem input){
  64         if (colNum == -1 || input == null)
  65                 return new SchemaItemList();
  66         SchemaItem output = input.schemaFor(colNum);
  67         if (output == null)
  68                 output = new SchemaItemList();
  69         return output;
  70     }
  71
  72     @Override
  73     public void eval(Tuple input, DataCollector output) throws IOException {
  74
  75         Datum d = null;
  76         try {
  77             d = input.getField(colNum);
  78         } catch (IOException e) {
  79             System.out.println("Warning: tuple does not contain field #" + colNum + "; substituting empty string.");
  80             output.add(new Tuple(new DataAtom()));  // insert default value
  81             return;
  82         }
  83
  84         Datum amendKey = null;
  85         if (input instanceof AmendableTuple) amendKey = ((AmendableTuple) input).getAmendKey();
  86
  87         if (d instanceof DataAtom) atomEval((DataAtom) d, output);
  88         else if (d instanceof Tuple) tupleEval((Tuple) d, output);
  89         else bagEval((DataBag) d, amendKey, output);
  90     }
  91
  92     @Override
  93     public Datum simpleEval(Tuple input) throws IOException {
  94
  95         Datum d = null;
  96         try {
  97             d = input.getField(colNum);
  98         }catch(ArrayIndexOutOfBoundsException exp) {
  99             throw new RuntimeException("ArrayException: |" + input + "| --> |" + colNum + "| |"  + alias + "|");
 100         } catch (IOException e) {
 101             System.out.println("Warning: tuple does not contain field #" + colNum + "; substituting empty string.");
 102             return new DataAtom();  // insert default value
 103         }
 104
 105         if (nestedEval == null) return d;
 106         else return nestedEval.simpleEval(d);
 107     }
 108 }