org.apache.giraph.block_app.reducers.array

Class BasicArrayReduce<S,R extends org.apache.hadoop.io.Writable>

java.lang.Object

org.apache.giraph.block_app.reducers.array.BasicArrayReduce<S,R>

Type Parameters:

S - Single value type

R - Reduced value type

All Implemented Interfaces:

ReduceOperation<org.apache.commons.lang3.tuple.Pair<PrimitiveRefs.IntRef,S>,WArrayList<R>>, org.apache.hadoop.io.Writable

public class BasicArrayReduce<S,R extends org.apache.hadoop.io.Writable>
extends Object
implements ReduceOperation<org.apache.commons.lang3.tuple.Pair<PrimitiveRefs.IntRef,S>,WArrayList<R>>

Efficient generic primitive array reduce operation. Allows two modes - fixed size, and infinite size (with keeping only actually used elements and resizing)

Constructor Summary

Constructors

Constructor and Description
BasicArrayReduce()
BasicArrayReduce(int fixedSize, PrimitiveTypeOps<R> typeOps, ReduceOperation<S,R> elementReduceOp) Create ReduceOperation that reduces BasicArrays by reducing individual elements, with predefined size.
BasicArrayReduce(PrimitiveTypeOps<R> typeOps, ReduceOperation<S,R> elementReduceOp) Create ReduceOperation that reduces BasicArrays by reducing individual elements, with unbounded size.

Method Summary

Modifier and Type	Method and Description
static <S,R extends org.apache.hadoop.io.Writable> ReducerArrayHandle<S,R>	createArrayHandles(int fixedSize, PrimitiveTypeOps<R> typeOps, ReduceOperation<S,R> elementReduceOp, CreateReducersApi.CreateReducerFunctionApi createFunction) Registers one new reducer, that will reduce BasicArray, by reducing individual elements using elementReduceOp, with predefined size.
static <S,R extends org.apache.hadoop.io.Writable> ReducerArrayHandle<S,R>	createArrayHandles(PrimitiveTypeOps<R> typeOps, ReduceOperation<S,R> elementReduceOp, CreateReducersApi.CreateReducerFunctionApi createFunction) Registers one new reducer, that will reduce BasicArray, by reducing individual elements using elementReduceOp, with unbounded size.
WArrayList<R>	createInitialValue() Return new reduced value which is neutral to reduce operation.
static <S,R extends org.apache.hadoop.io.Writable> ReducerArrayHandle<S,R>	createLocalArrayHandles(int fixedSize, PrimitiveTypeOps<R> typeOps, ReduceOperation<S,R> elementReduceOp, CreateReducersApi reduceApi) Registers one new local reducer, that will reduce BasicArray, by reducing individual elements using elementReduceOp, with predefined size.
static <S,R extends org.apache.hadoop.io.Writable> ReducerArrayHandle<S,R>	createLocalArrayHandles(PrimitiveTypeOps<R> typeOps, ReduceOperation<S,R> elementReduceOp, CreateReducersApi reduceApi) Registers one new local reducer, that will reduce BasicArray, by reducing individual elements using elementReduceOp, with unbounded size.
void	readFields(DataInput in)
WArrayList<R>	reduce(WArrayList<R> curValue, org.apache.commons.lang3.tuple.Pair<PrimitiveRefs.IntRef,S> valueToReduce) Add a new value.
WArrayList<R>	reduceMerge(WArrayList<R> curValue, WArrayList<R> valueToReduce) Add partially reduced value to current partially reduced value.
void	write(DataOutput out)

Methods inherited from class java.lang.Object

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

Constructor Detail

BasicArrayReduce

public BasicArrayReduce()

BasicArrayReduce

public BasicArrayReduce(int fixedSize,
                        PrimitiveTypeOps<R> typeOps,
                        ReduceOperation<S,R> elementReduceOp)

Create ReduceOperation that reduces BasicArrays by reducing individual elements, with predefined size.

Parameters:

fixedSize - Number of elements

typeOps - TypeOps of individual elements

elementReduceOp - ReduceOperation for individual elements

BasicArrayReduce

public BasicArrayReduce(PrimitiveTypeOps<R> typeOps,
                        ReduceOperation<S,R> elementReduceOp)

Create ReduceOperation that reduces BasicArrays by reducing individual elements, with unbounded size.

Parameters:

typeOps - TypeOps of individual elements

elementReduceOp - ReduceOperation for individual elements

Method Detail

createLocalArrayHandles

public static <S,R extends org.apache.hadoop.io.Writable> ReducerArrayHandle<S,R> createLocalArrayHandles(PrimitiveTypeOps<R> typeOps,
                                                                                                          ReduceOperation<S,R> elementReduceOp,
                                                                                                          CreateReducersApi reduceApi)

Registers one new local reducer, that will reduce BasicArray, by reducing individual elements using elementReduceOp, with unbounded size. This function will return ReducerArrayHandle, by which individual elements can be manipulated separately.

Parameters:

typeOps - TypeOps of individual elements

elementReduceOp - ReduceOperation for individual elements

reduceApi - API for creating reducers

Returns:

Created ReducerArrayHandle

createLocalArrayHandles

public static <S,R extends org.apache.hadoop.io.Writable> ReducerArrayHandle<S,R> createLocalArrayHandles(int fixedSize,
                                                                                                          PrimitiveTypeOps<R> typeOps,
                                                                                                          ReduceOperation<S,R> elementReduceOp,
                                                                                                          CreateReducersApi reduceApi)

Registers one new local reducer, that will reduce BasicArray, by reducing individual elements using elementReduceOp, with predefined size. This function will return ReducerArrayHandle, by which individual elements can be manipulated separately.

Parameters:

fixedSize - Number of elements

typeOps - TypeOps of individual elements

elementReduceOp - ReduceOperation for individual elements

reduceApi - API for creating reducers

Returns:

Created ReducerArrayHandle

createArrayHandles

public static <S,R extends org.apache.hadoop.io.Writable> ReducerArrayHandle<S,R> createArrayHandles(PrimitiveTypeOps<R> typeOps,
                                                                                                     ReduceOperation<S,R> elementReduceOp,
                                                                                                     CreateReducersApi.CreateReducerFunctionApi createFunction)

Registers one new reducer, that will reduce BasicArray, by reducing individual elements using elementReduceOp, with unbounded size. This function will return ReducerArrayHandle, by which individual elements can be manipulated separately.

Parameters:

typeOps - TypeOps of individual elements

elementReduceOp - ReduceOperation for individual elements

createFunction - Function for creating a reducer

Returns:

Created ReducerArrayHandle

createArrayHandles

public static <S,R extends org.apache.hadoop.io.Writable> ReducerArrayHandle<S,R> createArrayHandles(int fixedSize,
                                                                                                     PrimitiveTypeOps<R> typeOps,
                                                                                                     ReduceOperation<S,R> elementReduceOp,
                                                                                                     CreateReducersApi.CreateReducerFunctionApi createFunction)

Registers one new reducer, that will reduce BasicArray, by reducing individual elements using elementReduceOp, with predefined size. This function will return ReducerArrayHandle, by which individual elements can be manipulated separately.

Parameters:

fixedSize - Number of elements

typeOps - TypeOps of individual elements

elementReduceOp - ReduceOperation for individual elements

createFunction - Function for creating a reducer

Returns:

Created ReducerArrayHandle

createInitialValue

public WArrayList<R> createInitialValue()

Description copied from interface: ReduceOperation

Return new reduced value which is neutral to reduce operation.

Specified by:

createInitialValue in interface ReduceOperation<org.apache.commons.lang3.tuple.Pair<PrimitiveRefs.IntRef,S>,WArrayList<R extends org.apache.hadoop.io.Writable>>

Returns:

Neutral value

reduce

public WArrayList<R> reduce(WArrayList<R> curValue,
                            org.apache.commons.lang3.tuple.Pair<PrimitiveRefs.IntRef,S> valueToReduce)

Description copied from interface: ReduceOperation

Add a new value. Needs to be commutative and associative Commonly, returned value should be same as curValue argument.

Specified by:

reduce in interface ReduceOperation<org.apache.commons.lang3.tuple.Pair<PrimitiveRefs.IntRef,S>,WArrayList<R extends org.apache.hadoop.io.Writable>>

Parameters:

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

valueToReduce - Single value to be reduced

Returns:

reduced value

reduceMerge

public WArrayList<R> reduceMerge(WArrayList<R> curValue,
                                 WArrayList<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<org.apache.commons.lang3.tuple.Pair<PrimitiveRefs.IntRef,S>,WArrayList<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

write

public void write(DataOutput out)
           throws IOException

Specified by:

write in interface org.apache.hadoop.io.Writable

Throws:

IOException

readFields

public void readFields(DataInput in)
                throws IOException

Specified by:

readFields in interface org.apache.hadoop.io.Writable

Throws:

IOException