org.apache.pig.impl.builtin

Class StreamingUDF

java.lang.Object

org.apache.pig.EvalFunc<java.lang.Object>

org.apache.pig.impl.builtin.StreamingUDF

public class StreamingUDF
extends EvalFunc<java.lang.Object>

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
class	StreamingUDF.ProcessKiller

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

EvalFunc.SchemaType

Field Summary

Fields

Modifier and Type	Field and Description
static java.lang.String	TURN_ON_OUTPUT_CAPTURING

Fields inherited from class org.apache.pig.EvalFunc

pigLogger, reporter, returnType

Constructor Summary

Constructors

Constructor and Description
StreamingUDF(java.lang.String language, java.lang.String filePath, java.lang.String funcName, java.lang.String outputSchemaString, java.lang.String schemaLineNumber, java.lang.String execType, java.lang.String isIllustrate)

Method Summary

Modifier and Type	Method and Description
java.lang.Object	exec(Tuple input) This callback method must be implemented by all subclasses.
Schema	outputSchema(Schema input) Report the schema of the output of this UDF.

Methods inherited from class org.apache.pig.EvalFunc

allowCompileTimeCalculation, finish, getArgToFuncMapping, getCacheFiles, getInputSchema, getLoadCaster, getLogger, getPigLogger, getReporter, getReturnType, getSchemaName, getSchemaType, getShipFiles, isAsynchronous, needEndOfAllInputProcessing, progress, setEndOfAllInput, 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

TURN_ON_OUTPUT_CAPTURING

public static final java.lang.String TURN_ON_OUTPUT_CAPTURING

See Also:

Constant Field Values

Constructor Detail

StreamingUDF

public StreamingUDF(java.lang.String language,
                    java.lang.String filePath,
                    java.lang.String funcName,
                    java.lang.String outputSchemaString,
                    java.lang.String schemaLineNumber,
                    java.lang.String execType,
                    java.lang.String isIllustrate)
             throws StreamingUDFOutputSchemaException,
                    ExecException

Throws:

StreamingUDFOutputSchemaException

ExecException

Method Detail

exec

public java.lang.Object exec(Tuple input)
                      throws java.io.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<java.lang.Object>

Parameters:

input - the Tuple to be processed.

Returns:

result, of type T.

Throws:

java.io.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<java.lang.Object>

Parameters:

input - Schema of the input

Returns:

Schema of the output