org.apache.giraph.block_app.framework.piece.global_comm.internal

Class CreateReducersApiWrapper

java.lang.Object

org.apache.giraph.block_app.framework.piece.global_comm.internal.CreateReducersApiWrapper

All Implemented Interfaces:

BlockConfApi, CreateReducersApi

public class CreateReducersApiWrapper
extends Object
implements CreateReducersApi

Wrapping masterApi and reducers handler into API for creating reducer handles.

Nested Class Summary

Nested classes/interfaces inherited from interface org.apache.giraph.block_app.framework.api.CreateReducersApi

CreateReducersApi.CreateReducerFunctionApi

Constructor Summary

Constructors

Constructor and Description
CreateReducersApiWrapper(BlockMasterApi masterApi, ReducersForPieceHandler reducersApi)

Method Summary

Modifier and Type	Method and Description
<S,R extends org.apache.hadoop.io.Writable> ReducerHandle<S,R>	createGlobalReducer(ReduceOperation<S,R> reduceOp) Create global reducer, returning a handle to it.
<S,R extends org.apache.hadoop.io.Writable> ReducerHandle<S,R>	createGlobalReducer(ReduceOperation<S,R> reduceOp, R globalInitialValue) Create global reducer, returning a handle to it.
<S,R extends org.apache.hadoop.io.Writable> ReducerHandle<S,R>	createLocalReducer(ReduceOperation<S,R> reduceOp) Create local reducer, returning a handle to it.
<S,R extends org.apache.hadoop.io.Writable> ReducerHandle<S,R>	createLocalReducer(ReduceOperation<S,R> reduceOp, R globalInitialValue) Create local reducer, returning a handle to it.
ImmutableClassesGiraphConfiguration<?,?,?>	getConf() Return the configuration used by this object.

Methods inherited from class java.lang.Object

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

Constructor Detail

CreateReducersApiWrapper

public CreateReducersApiWrapper(BlockMasterApi masterApi,
                                ReducersForPieceHandler reducersApi)

Method Detail

createLocalReducer

public <S,R extends org.apache.hadoop.io.Writable> ReducerHandle<S,R> createLocalReducer(ReduceOperation<S,R> reduceOp)

Description copied from interface: CreateReducersApi

Create local reducer, returning a handle to it. Local reducer means that each worker thread has it's own local partially reduced value, which are at the end reduced all together. Preferable, unless it cannot be used, because all copies of the object do not fit the memory.

Specified by:

createLocalReducer in interface CreateReducersApi

createLocalReducer

public <S,R extends org.apache.hadoop.io.Writable> ReducerHandle<S,R> createLocalReducer(ReduceOperation<S,R> reduceOp,
                                                                                         R globalInitialValue)

Description copied from interface: CreateReducersApi

Create local reducer, returning a handle to it. Local reducer means that each worker thread has it's own local partially reduced value, which are at the end reduced all together. Preferable, unless it cannot be used, because all copies of the object do not fit the memory.

Specified by:

createLocalReducer in interface CreateReducersApi

createGlobalReducer

public <S,R extends org.apache.hadoop.io.Writable> ReducerHandle<S,R> createGlobalReducer(ReduceOperation<S,R> reduceOp)

Description copied from interface: CreateReducersApi

Create global reducer, returning a handle to it. Global reducer means that there is only one value for each worker, and each call to reduce will have to obtain a global lock, and incur synchronization costs. Use only when objects are so large, that having many copies cannot fit into memory.

Specified by:

createGlobalReducer in interface CreateReducersApi

createGlobalReducer

public <S,R extends org.apache.hadoop.io.Writable> ReducerHandle<S,R> createGlobalReducer(ReduceOperation<S,R> reduceOp,
                                                                                          R globalInitialValue)

Description copied from interface: CreateReducersApi

Create global reducer, returning a handle to it. Global reducer means that there is only one value for each worker, and each call to reduce will have to obtain a global lock, and incur synchronization costs. Use only when objects are so large, that having many copies cannot fit into memory.

Specified by:

createGlobalReducer in interface CreateReducersApi

getConf

public ImmutableClassesGiraphConfiguration<?,?,?> getConf()

Description copied from interface: BlockConfApi

Return the configuration used by this object.

Specified by:

getConf in interface BlockConfApi

Returns:

Set configuration