org.apache.datasketches.pig.sampling

Class VarOptUnion

java.lang.Object

org.apache.pig.EvalFunc<T>

org.apache.pig.AccumulatorEvalFunc<org.apache.pig.data.DataByteArray>

org.apache.datasketches.pig.sampling.VarOptUnion

All Implemented Interfaces:

org.apache.pig.Accumulator<org.apache.pig.data.DataByteArray>, org.apache.pig.Algebraic

public class VarOptUnion
extends org.apache.pig.AccumulatorEvalFunc<org.apache.pig.data.DataByteArray>
implements org.apache.pig.Algebraic

Accepts binary VarOpt sketch images and unions them into a single binary output sketch. Due to using opaque binary objects, schema information is unavailable.

The VarOpt sketch can handle input sketches with different values of k, and will produce a result using the largest number of samples that still produces a valid VarOpt sketch.

Author:

Jon Malkin

Nested Class Summary

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

org.apache.pig.EvalFunc.SchemaType

Field Summary

Fields inherited from class org.apache.pig.EvalFunc

log, pigLogger, reporter, returnType

Constructor Summary

Constructors

Constructor and Description
VarOptUnion(String kStr) VarOpt union constructor.

Method Summary

Modifier and Type	Method and Description
void	accumulate(org.apache.pig.data.Tuple inputTuple)
void	cleanup()
String	getFinal()
String	getInitial()
String	getIntermed()
org.apache.pig.data.DataByteArray	getValue()
org.apache.pig.impl.logicalLayer.schema.Schema	outputSchema(org.apache.pig.impl.logicalLayer.schema.Schema input)

Methods inherited from class org.apache.pig.AccumulatorEvalFunc

exec

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

VarOptUnion

public VarOptUnion(String kStr)

VarOpt union constructor.

Parameters:

kStr - String indicating the maximum number of desired entries in the sample.

Method Detail

accumulate

public void accumulate(org.apache.pig.data.Tuple inputTuple)
                throws IOException

Specified by:

accumulate in interface org.apache.pig.Accumulator<org.apache.pig.data.DataByteArray>

Specified by:

accumulate in class org.apache.pig.AccumulatorEvalFunc<org.apache.pig.data.DataByteArray>

Throws:

IOException

getValue

public org.apache.pig.data.DataByteArray getValue()

Specified by:

getValue in interface org.apache.pig.Accumulator<org.apache.pig.data.DataByteArray>

Specified by:

getValue in class org.apache.pig.AccumulatorEvalFunc<org.apache.pig.data.DataByteArray>

cleanup

public void cleanup()

Specified by:

cleanup in interface org.apache.pig.Accumulator<org.apache.pig.data.DataByteArray>

Specified by:

cleanup in class org.apache.pig.AccumulatorEvalFunc<org.apache.pig.data.DataByteArray>

getInitial

public String getInitial()

Specified by:

getInitial in interface org.apache.pig.Algebraic

getIntermed

public String getIntermed()

Specified by:

getIntermed in interface org.apache.pig.Algebraic

getFinal

public String getFinal()

Specified by:

getFinal in interface org.apache.pig.Algebraic

outputSchema

public org.apache.pig.impl.logicalLayer.schema.Schema outputSchema(org.apache.pig.impl.logicalLayer.schema.Schema input)

Overrides:

outputSchema in class org.apache.pig.EvalFunc<org.apache.pig.data.DataByteArray>