org.apache.giraph.reducers

Class ReduceSameTypeOperation<R extends org.apache.hadoop.io.Writable>

java.lang.Object

org.apache.giraph.reducers.ReduceSameTypeOperation<R>

Type Parameters:

R - Reduced object type.

All Implemented Interfaces:

ReduceOperation<R,R>, org.apache.hadoop.io.Writable

Direct Known Subclasses:

AggregatorReduceOperation, AndReduce, LongXorReduce, MaxPairReducer, MaxReduce, MinReduce, OrReduce, ReducersBenchmark.TestLongSumReducer, SumReduce

public abstract class ReduceSameTypeOperation<R extends org.apache.hadoop.io.Writable>
extends Object
implements ReduceOperation<R,R>

ReduceOperation object when single object being reduced is of same type as reduced value.

Constructor Summary

Constructors

Constructor and Description
ReduceSameTypeOperation()

Method Summary

Modifier and Type	Method and Description
R	reduceMerge(R curValue, R valueToReduce) Add partially reduced value to current partially reduced value.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.apache.giraph.reducers.ReduceOperation

createInitialValue, reduce

Methods inherited from interface org.apache.hadoop.io.Writable

readFields, write

Constructor Detail

ReduceSameTypeOperation

public ReduceSameTypeOperation()

Method Detail

reduceMerge

public final R reduceMerge(R curValue,
                           R valueToReduce)

Description copied from interface: ReduceOperation

Add partially reduced value to current partially reduced value. Commonly, returned value should be same as curValue argument.

Specified by:

reduceMerge in interface ReduceOperation<R extends org.apache.hadoop.io.Writable,R extends org.apache.hadoop.io.Writable>

Parameters:

curValue - Partial value into which to reduce and store the result

valueToReduce - Partial value to be reduced

Returns:

reduced value