datafu.pig.bags

Class CountEach

java.lang.Object

org.apache.pig.EvalFunc<T>

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

datafu.pig.bags.CountEach

All Implemented Interfaces:

org.apache.pig.Accumulator<org.apache.pig.data.DataBag>

public class CountEach
extends org.apache.pig.AccumulatorEvalFunc<org.apache.pig.data.DataBag>

Generates a count of the number of times each distinct tuple appears in a bag. Example:

 
 DEFINE CountEach datafu.pig.bags.CountEach();
 DEFINE CountEachFlatten datafu.pig.bags.CountEach('flatten');
 
 -- input: 
 -- ({(A),(A),(C),(B)})
 input = LOAD 'input' AS (B: bag {T: tuple(alpha:CHARARRAY, numeric:INT)});
 
 -- output: 
 -- {((A),2),((C),1),((B),1)}
 output = FOREACH input GENERATE CountEach(B); 
 
 -- output_flatten: 
 -- ({(A,2),(C,1),(B,1)})
 output_flatten = FOREACH input GENERATE CountEachFlatten(B);
  
 

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
CountEach()
CountEach(java.lang.String arg)

Method Summary

Modifier and Type	Method and Description
void	accumulate(org.apache.pig.data.Tuple input)
void	cleanup()
org.apache.pig.data.DataBag	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, getLogger, getPigLogger, getReporter, getReturnType, getSchemaName, getSchemaType, getShipFiles, 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

Constructor Detail

CountEach

public CountEach()

CountEach

public CountEach(java.lang.String arg)

Method Detail

accumulate

public void accumulate(org.apache.pig.data.Tuple input)
                throws java.io.IOException

Specified by:

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

Specified by:

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

Throws:

java.io.IOException

getValue

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

Specified by:

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

Specified by:

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

cleanup

public void cleanup()

Specified by:

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

Specified by:

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

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.DataBag>