org.apache.flink.runtime.operators

类 GroupReduceCombineDriver<IN,OUT>

java.lang.Object

org.apache.flink.runtime.operators.GroupReduceCombineDriver<IN,OUT>

类型参数:

IN - The data type consumed by the combiner.

OUT - The data type produced by the combiner.

所有已实现的接口:

Driver<org.apache.flink.api.common.functions.GroupCombineFunction<IN,OUT>,OUT>

public class GroupReduceCombineDriver<IN,OUT>
extends Object
implements Driver<org.apache.flink.api.common.functions.GroupCombineFunction<IN,OUT>,OUT>

Non-chained combine driver which is used for a CombineGroup transformation or a GroupReduce transformation where the user supplied a RichGroupReduceFunction with a combine method. The combining is performed in memory with a lazy approach which only combines elements which currently fit in the sorter. This may lead to a partial solution. In the case of the RichGroupReduceFunction this partial result is transformed into a proper deterministic result. The CombineGroup uses the GroupCombineFunction interface which allows to combine values of type IN to any type of type OUT. In contrast, the RichGroupReduceFunction requires the combine method to have the same input and output type to be able to reduce the elements after the combine from IN to OUT.

The GroupReduceCombineDriver uses a combining iterator over its input. The output of the iterator is emitted.

构造器概要

构造器

构造器和说明
GroupReduceCombineDriver()

方法概要

限定符和类型	方法和说明
void	cancel() This method is invoked when the driver must aborted in mid processing.
void	cleanup() This method is invoked in any case (clean termination and exception) at the end of the tasks operation.
int	getNumberOfDriverComparators() Gets the number of comparators required for this driver.
int	getNumberOfInputs() Gets the number of inputs that the task has.
long	getOversizedRecordCount() Gets the number of oversized records handled by this combiner.
Class<org.apache.flink.api.common.functions.GroupCombineFunction<IN,OUT>>	getStubType() Gets the class of the stub type that is run by this task.
void	prepare() This method is called before the user code is opened.
void	run() The main operation method of the task.
void	setup(TaskContext<org.apache.flink.api.common.functions.GroupCombineFunction<IN,OUT>,OUT> context)

从类继承的方法 java.lang.Object

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

构造器详细资料

GroupReduceCombineDriver

public GroupReduceCombineDriver()

方法详细资料

setup

public void setup(TaskContext<org.apache.flink.api.common.functions.GroupCombineFunction<IN,OUT>,OUT> context)

指定者:

setup 在接口中 Driver<org.apache.flink.api.common.functions.GroupCombineFunction<IN,OUT>,OUT>

getNumberOfInputs

public int getNumberOfInputs()

从接口复制的说明: Driver

Gets the number of inputs that the task has.

指定者:

getNumberOfInputs 在接口中 Driver<org.apache.flink.api.common.functions.GroupCombineFunction<IN,OUT>,OUT>

返回:

The number of inputs.

getStubType

public Class<org.apache.flink.api.common.functions.GroupCombineFunction<IN,OUT>> getStubType()

从接口复制的说明: Driver

Gets the class of the stub type that is run by this task. For example, a MapTask should return MapFunction.class.

指定者:

getStubType 在接口中 Driver<org.apache.flink.api.common.functions.GroupCombineFunction<IN,OUT>,OUT>

返回:

The class of the stub type run by the task.

getNumberOfDriverComparators

public int getNumberOfDriverComparators()

从接口复制的说明: Driver

Gets the number of comparators required for this driver.

指定者:

getNumberOfDriverComparators 在接口中 Driver<org.apache.flink.api.common.functions.GroupCombineFunction<IN,OUT>,OUT>

返回:

The number of comparators required for this driver.

prepare

public void prepare()
             throws Exception

从接口复制的说明: Driver

This method is called before the user code is opened. An exception thrown by this method signals failure of the task.

指定者:

prepare 在接口中 Driver<org.apache.flink.api.common.functions.GroupCombineFunction<IN,OUT>,OUT>

抛出:

Exception - Exceptions may be forwarded and signal task failure.

run

public void run()
         throws Exception

从接口复制的说明: Driver

The main operation method of the task. It should call the user code with the data subsets until the input is depleted.

指定者:

run 在接口中 Driver<org.apache.flink.api.common.functions.GroupCombineFunction<IN,OUT>,OUT>

抛出:

Exception - Any exception thrown by this method signals task failure. Because exceptions in the user code typically signal situations where this instance in unable to proceed, exceptions from the user code should be forwarded.

cleanup

public void cleanup()
             throws Exception

从接口复制的说明: Driver

This method is invoked in any case (clean termination and exception) at the end of the tasks operation.

指定者:

cleanup 在接口中 Driver<org.apache.flink.api.common.functions.GroupCombineFunction<IN,OUT>,OUT>

抛出:

Exception - Exceptions may be forwarded.

cancel

public void cancel()

从接口复制的说明: Driver

This method is invoked when the driver must aborted in mid processing. It is invoked asynchronously by a different thread.

指定者:

cancel 在接口中 Driver<org.apache.flink.api.common.functions.GroupCombineFunction<IN,OUT>,OUT>

getOversizedRecordCount

public long getOversizedRecordCount()

Gets the number of oversized records handled by this combiner.

返回:

The number of oversized records handled by this combiner.