org.apache.pig.scripting.jruby
Class JrubyAlgebraicEvalFunc.AlgebraicFunctionWrapper<T>

java.lang.Object
  org.apache.pig.EvalFunc<T>
      org.apache.pig.scripting.jruby.JrubyAlgebraicEvalFunc.AlgebraicFunctionWrapper<T>

Direct Known Subclasses:

JrubyAlgebraicEvalFunc.Final, JrubyAlgebraicEvalFunc.Initial, JrubyAlgebraicEvalFunc.Intermed

Enclosing class:

JrubyAlgebraicEvalFunc<T>

public abstract static class JrubyAlgebraicEvalFunc.AlgebraicFunctionWrapper<T>
extends EvalFunc<T>

This is a lightweight wrapper shell that registers information on the method being called, and provides the initializer that the static Algebraic classes (Initial, Intermed, Final) will use to execute.

Nested Class Summary

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

EvalFunc.SchemaType

Field Summary

protected boolean	isInitialized
protected Object	receiver
protected String	stage

Fields inherited from class org.apache.pig.EvalFunc

log, pigLogger, reporter, returnType

Constructor Summary

JrubyAlgebraicEvalFunc.AlgebraicFunctionWrapper()

JrubyAlgebraicEvalFunc.AlgebraicFunctionWrapper(String fileName, String functionName, String stage)
In addition to registering the fileName and the functionName (which are given based on the arguments passed to super() in the containing class's constructor, each extending class will register their "stage," which will serve as the method to invoke on the Ruby class.

Method Summary

abstract T	exec(Tuple input) This callback method must be implemented by all subclasses.
String	getFileName()
String	getFunctionName()
Object	getReceiver()
String	getStage()
void	initialize()
boolean	isInitialized()

Methods inherited from class org.apache.pig.EvalFunc

finish, getArgToFuncMapping, getCacheFiles, getInputSchema, getLogger, getPigLogger, getReporter, getReturnType, getSchemaName, getSchemaType, isAsynchronous, outputSchema, 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

receiver

protected Object receiver

isInitialized

protected boolean isInitialized

stage

protected String stage

Constructor Detail

JrubyAlgebraicEvalFunc.AlgebraicFunctionWrapper

public JrubyAlgebraicEvalFunc.AlgebraicFunctionWrapper()

JrubyAlgebraicEvalFunc.AlgebraicFunctionWrapper

public JrubyAlgebraicEvalFunc.AlgebraicFunctionWrapper(String fileName,
                                                       String functionName,
                                                       String stage)

In addition to registering the fileName and the functionName (which are given based on the arguments passed to super() in the containing class's constructor, each extending class will register their "stage," which will serve as the method to invoke on the Ruby class.

Method Detail

getStage

public String getStage()

getReceiver

public Object getReceiver()

getFileName

public String getFileName()

getFunctionName

public String getFunctionName()

isInitialized

public boolean isInitialized()

initialize

public void initialize()

exec

public abstract 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