org.apache.pig.scripting.groovy
Class GroovyEvalFunc<T>

java.lang.Object
  org.apache.pig.EvalFunc<T>
      org.apache.pig.scripting.groovy.GroovyEvalFunc<T>

Direct Known Subclasses:

GroovyAlgebraicEvalFunc.AlgebraicFunctionWrapper, GroovyEvalFuncObject

public class GroovyEvalFunc<T>
extends EvalFunc<T>

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.pig.EvalFunc

EvalFunc.SchemaType

Field Summary

protected Method

method

Fields inherited from class org.apache.pig.EvalFunc

log, pigLogger, reporter, returnType

Constructor Summary

GroovyEvalFunc()

GroovyEvalFunc(String path, String namespace, String methodName)

GroovyEvalFunc(String path, String namespace, String methodName, Object target)

Method Summary

T	exec(Tuple input) This callback method must be implemented by all subclasses.
Object	getInvocationTarget()
Schema	outputSchema(Schema input) Report the schema of the output of this UDF.

Methods inherited from class org.apache.pig.EvalFunc

finish, getArgToFuncMapping, getCacheFiles, getInputSchema, getLogger, getPigLogger, getReporter, getReturnType, getSchemaName, getSchemaType, isAsynchronous, progress, setInputSchema, setPigLogger, setReporter, setUDFContextSignature, warn

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

method

protected Method method

Constructor Detail

GroovyEvalFunc

public GroovyEvalFunc()

GroovyEvalFunc

public GroovyEvalFunc(String path,
                      String namespace,
                      String methodName)
               throws IOException

Throws:

IOException

GroovyEvalFunc

public GroovyEvalFunc(String path,
                      String namespace,
                      String methodName,
                      Object target)
               throws IOException

Throws:

IOException

Method Detail

exec

public T exec(Tuple input)
       throws IOException

Description copied from class: EvalFunc

This callback method must be implemented by all subclasses. This is the method that will be invoked on every Tuple of a given dataset. Since the dataset may be divided up in a variety of ways the programmer should not make assumptions about state that is maintained between invocations of this method.

Specified by:

exec in class EvalFunc<T>

Parameters:

input - the Tuple to be processed.

Returns:

result, of type T.

Throws:

IOException

outputSchema

public Schema outputSchema(Schema input)

Description copied from class: EvalFunc

Report the schema of the output of this UDF. Pig will make use of this in error checking, optimization, and planning. The schema of input data to this UDF is provided.

The default implementation interprets the OutputSchema annotation, if one is present. Otherwise, it returns null (no known output schema).

Overrides:

outputSchema in class EvalFunc<T>

Parameters:

input - Schema of the input

Returns:

Schema of the output

getInvocationTarget

public Object getInvocationTarget()