org.apache.pig.piggybank.evaluation.string

Class LookupInFiles

java.lang.Object

org.apache.pig.EvalFunc<Integer>

org.apache.pig.piggybank.evaluation.string.LookupInFiles

public class LookupInFiles
extends EvalFunc<Integer>

Syntax:

int lookupInFiles(String expression,... ).

Input:

files are text files on DFS.

Output:

if any file contains expression, return 1, otherwise, 0.

Nested Class Summary

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

EvalFunc.SchemaType

Field Summary

Fields inherited from class org.apache.pig.EvalFunc

log, pigLogger, reporter, returnType

Constructor Summary

Constructors

Constructor and Description
LookupInFiles()

Method Summary

Modifier and Type	Method and Description
Integer	exec(Tuple input) This callback method must be implemented by all subclasses.
void	init(Tuple tuple)
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

Constructor Detail

LookupInFiles

public LookupInFiles()

Method Detail

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<Integer>

Parameters:

input - Schema of the input

Returns:

Schema of the output

init

public void init(Tuple tuple)
          throws IOException

Throws:

IOException

exec

public Integer 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<Integer>

Parameters:

input - the Tuple to be processed.

Returns:

result, of type T.

Throws:

IOException