org.apache.flink.runtime.asyncprocessing

类 AbstractStateIterator<T>

java.lang.Object

org.apache.flink.runtime.asyncprocessing.AbstractStateIterator<T>

所有已实现的接口:

org.apache.flink.api.common.state.v2.StateIterator<T>

public abstract class AbstractStateIterator<T>
extends Object
implements org.apache.flink.api.common.state.v2.StateIterator<T>

A StateIterator implementation to facilitate async data load of iterator. Each state backend could override this class to maintain more variables in need. Any subclass should implement two methods, hasNext() and nextPayloadForContinuousLoading(). The philosophy behind this class is to carry some already loaded elements and provide iterating right on the task thread, and load following ones if needed (determined by hasNext()) by creating **ANOTHER** iterating request. Thus, later it returns another iterator instance, and we continue to apply the user iteration on that instance. The whole elements will be iterated by recursive call of #onNext().

构造器概要

构造器

构造器和说明
AbstractStateIterator(org.apache.flink.api.common.state.v2.State originalState, StateRequestType requestType, StateRequestHandler stateHandler, Collection<T> partialResult)

方法概要

限定符和类型	方法和说明
protected StateRequestType	getRequestType()
protected abstract boolean	hasNext() Return whether this iterator has more elements to load besides current cache.
boolean	isEmpty()
protected abstract Object	nextPayloadForContinuousLoading() To perform following loading, build and get next payload for the next request.
org.apache.flink.api.common.state.v2.StateFuture<Void>	onNext(Consumer<T> iterating)
<U> org.apache.flink.api.common.state.v2.StateFuture<Collection<U>>	onNext(Function<T,org.apache.flink.api.common.state.v2.StateFuture<? extends U>> iterating)

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

AbstractStateIterator

public AbstractStateIterator(org.apache.flink.api.common.state.v2.State originalState,
                             StateRequestType requestType,
                             StateRequestHandler stateHandler,
                             Collection<T> partialResult)

方法详细资料

hasNext

protected abstract boolean hasNext()

Return whether this iterator has more elements to load besides current cache.

nextPayloadForContinuousLoading

protected abstract Object nextPayloadForContinuousLoading()

To perform following loading, build and get next payload for the next request. This will put into StateRequest.getPayload().

返回:

the packed payload for next loading.

getRequestType

protected StateRequestType getRequestType()

onNext

public <U> org.apache.flink.api.common.state.v2.StateFuture<Collection<U>> onNext(Function<T,org.apache.flink.api.common.state.v2.StateFuture<? extends U>> iterating)

指定者:

onNext 在接口中 org.apache.flink.api.common.state.v2.StateIterator<T>

onNext

public org.apache.flink.api.common.state.v2.StateFuture<Void> onNext(Consumer<T> iterating)

指定者:

onNext 在接口中 org.apache.flink.api.common.state.v2.StateIterator<T>

isEmpty

public boolean isEmpty()

指定者:

isEmpty 在接口中 org.apache.flink.api.common.state.v2.StateIterator<T>