java/pig-galago/src/com/yahoo/pig/impl/eval/func/BagFuncEvalItem.java

   1 /*
   2  * Copyright (c) 2007 Yahoo! Inc.  All rights reserved.
   3  * See accompanying LICENSE file.
   4  */
   5 package com.yahoo.pig.impl.eval.func;
   6
   7 import java.io.IOException;
   8
   9 import com.yahoo.pig.BagEvalFunc;
  10 import com.yahoo.pig.data.*;
  11 import com.yahoo.pig.impl.PigContext;
  12 import com.yahoo.pig.impl.eval.EvalItemList;
  13
  14 public class BagFuncEvalItem extends FuncEvalItem {
  15
  16     public BagFuncEvalItem(PigContext pigContext, BagEvalFunc func, EvalItemList args) {
  17         super(pigContext, func, args);
  18     }
  19
  20     @Override
  21     public void eval(Tuple input, DataCollector output) throws IOException {
  22
  23         Datum amendKey = null;
  24         if (input instanceof AmendableTuple) amendKey = ((AmendableTuple) input).getAmendKey();
  25
  26         output = setupBagProcessingPipeline(amendKey, output);
  27
  28         ((BagEvalFunc) func).exec(args.simpleEval(input), output);
  29         if (!output.isStale())
  30                 output.add(null);  // EOF
  31     }
  32
  33     @Override
  34     public DataBag simpleEval(Tuple input) throws IOException {
  35         DataBag d = BagFactory.getInstance().getNewBag();
  36
  37         DataCollector emitTo = d;
  38
  39         if (nestedEval != null) emitTo = nestedEval.collector(d);
  40
  41         ((BagEvalFunc) func).exec(args.simpleEval(input), emitTo);
  42
  43         return d;
  44     }
  45
  46     @Override
  47     public String stringVal(Tuple tup) throws IOException {
  48         throw new IOException("Internal error: illegal to call stringVal() on FuncEvalItem");
  49     }
  50
  51     @Override
  52     public Double doubleVal(Tuple tup) throws IOException {
  53         throw new IOException("Internal error: illegal to call doubleVal() on FuncEvalItem");
  54     }
  55
  56 }