org.apache.pig.builtin
Class IntSum

java.lang.Object
  extended by org.apache.pig.EvalFunc<Long>
      extended by org.apache.pig.builtin.IntSum
All Implemented Interfaces:
Algebraic

public class IntSum
extends EvalFunc<Long>
implements Algebraic

Generates the sum of the Integer in the first field of a tuple.


Nested Class Summary
static class IntSum.Final
           
static class IntSum.Initial
           
static class IntSum.Intermediate
           
 
Field Summary
 
Fields inherited from class org.apache.pig.EvalFunc
log, pigLogger, reporter, returnType
 
Constructor Summary
IntSum()
           
 
Method Summary
 Long exec(Tuple input)
          This callback method must be implemented by all subclasses.
 String getFinal()
           
 String getInitial()
           
 String getIntermed()
           
 Schema outputSchema(Schema input)
           
protected static Long sum(Tuple input)
           
protected static Long sumLongs(Tuple input)
           
 
Methods inherited from class org.apache.pig.EvalFunc
finish, getArgToFuncMapping, getLogger, getPigLogger, getReporter, getReturnType, getSchemaName, isAsynchronous, progress, setPigLogger, setReporter, warn
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

IntSum

public IntSum()
Method Detail

exec

public Long 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<Long>
Parameters:
input - the Tuple to be processed.
Returns:
result, of type T.
Throws:
IOException

getInitial

public String getInitial()
Specified by:
getInitial in interface Algebraic
Returns:
A string to instatiate f_init. f_init should be an eval func

getIntermed

public String getIntermed()
Specified by:
getIntermed in interface Algebraic
Returns:
A string to instantiate f_intermed. f_intermed should be an eval func

getFinal

public String getFinal()
Specified by:
getFinal in interface Algebraic
Returns:
A string to instantiate f_final. f_final should be an eval func parametrized by the same datum as the eval func implementing this interface

sumLongs

protected static Long sumLongs(Tuple input)
                        throws ExecException
Throws:
ExecException

sum

protected static Long sum(Tuple input)
                   throws ExecException
Throws:
ExecException

outputSchema

public Schema outputSchema(Schema input)
Overrides:
outputSchema in class EvalFunc<Long>
Parameters:
input - Schema of the input
Returns:
Schema of the output


Copyright © ${year} The Apache Software Foundation