@InterfaceAudience.Public @InterfaceStability.Unstable public abstract class IteratingAccumulatorEvalFunc<T> extends AccumulatorEvalFunc<T> implements TerminatingAccumulator<T>
public class IsEmpty extends IteratingAccumulatorEvalFunc {
public Boolean exec(Iterator iter) throws IOException {
return !iter.hashNext();
}
} public class Count extends IteratingAccumulatorEvalFunc {
public Long exec(Iterator iter) throws IOException {
long ct = 0;
for (; iter.hasNext(); iter.next()) {
ct++;
}
return ct;
}
} EvalFunc.SchemaTypelog, pigLogger, reporter, returnType| Constructor and Description |
|---|
IteratingAccumulatorEvalFunc() |
| Modifier and Type | Method and Description |
|---|---|
void |
accumulate(Tuple input)
Pass tuples to the UDF.
|
void |
cleanup()
Called after getValue() to prepare processing for next key.
|
abstract T |
exec(java.util.Iterator<Tuple> iter) |
T |
getValue()
Called when all tuples from current key have been passed to accumulate.
|
boolean |
isFinished() |
execallowCompileTimeCalculation, finish, getArgToFuncMapping, getCacheFiles, getInputSchema, getLoadCaster, getLogger, getPigLogger, getReporter, getReturnType, getSchemaName, getSchemaType, getShipFiles, isAsynchronous, needEndOfAllInputProcessing, outputSchema, progress, setEndOfAllInput, setInputSchema, setPigLogger, setReporter, setUDFContextSignature, warnpublic boolean isFinished()
isFinished in interface TerminatingAccumulator<T>public void accumulate(Tuple input) throws java.io.IOException
Accumulatoraccumulate in interface Accumulator<T>accumulate in class AccumulatorEvalFunc<T>input - A tuple containing a single field, which is a bag. The bag will contain the set
of tuples being passed to the UDF in this iteration.java.io.IOExceptionpublic T getValue()
AccumulatorgetValue in interface Accumulator<T>getValue in class AccumulatorEvalFunc<T>public void cleanup()
Accumulatorcleanup in interface Accumulator<T>cleanup in class AccumulatorEvalFunc<T>Copyright © 2007-2017 The Apache Software Foundation