Package org.apache.druid.frame.processor

Class ReturnOrAwait<T>

java.lang.Object

org.apache.druid.frame.processor.ReturnOrAwait<T>

public class ReturnOrAwait<T>
extends Object

Instances of this class are returned by FrameProcessor.runIncrementally(it.unimi.dsi.fastutil.ints.IntSet), and are used by FrameProcessorExecutor to manage execution. An instance can be a "return" with a result, which means that the FrameProcessor is done working. In this case isReturn() is true and value() contains the result. An instance can also be an "await", which means that the FrameProcessor wants to be scheduled again in the future. In this case isAwait() is true, awaitSet() contains the set of input channels to wait for, and isAwaitAll() is whether the processor wants to wait for all channels, or any channel.

Method Summary

Modifier and Type	Method	Description
static <T> ReturnOrAwait<T>	awaitAll(int count)	Wait for all of a certain number of channels.
static <T> ReturnOrAwait<T>	awaitAll(it.unimi.dsi.fastutil.ints.IntSet await)	Wait for all provided channels to become readable (or finished).
static <T> ReturnOrAwait<T>	awaitAny(it.unimi.dsi.fastutil.ints.IntSet await)	Wait for any of the provided channels to become readable (or finished).
it.unimi.dsi.fastutil.ints.IntSet	awaitSet()	The set of channels the processors wants to wait for.
boolean	equals(Object o)
int	hashCode()
boolean	isAwait()	Whether the processor wants to be scheduled again.
boolean	isAwaitAll()	Whether the processor wants to wait for all channels in awaitSet() (true), or any channel (false)
boolean	isReturn()	Whether the processor has returned a value.
static <T> ReturnOrAwait<T>	returnObject(T o)	Return a result.
static <T> ReturnOrAwait<T>	runAgain()	Wait for nothing; that is: run again as soon as possible.
String	toString()
T	value()	The returned result.

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Method Detail

runAgain

public static <T> ReturnOrAwait<T> runAgain()

Wait for nothing; that is: run again as soon as possible.

awaitAll

public static <T> ReturnOrAwait<T> awaitAll(it.unimi.dsi.fastutil.ints.IntSet await)

Wait for all provided channels to become readable (or finished). Numbers in this set correspond to positions in the FrameProcessor.inputChannels() list. It is OK to pass in a mutable set, because this method does not modify the set or retain a reference to it.

awaitAll

public static <T> ReturnOrAwait<T> awaitAll(int count)

Wait for all of a certain number of channels.

awaitAny

public static <T> ReturnOrAwait<T> awaitAny(it.unimi.dsi.fastutil.ints.IntSet await)

Wait for any of the provided channels to become readable (or finished). When using this, callers should consider removing any fully-processed and finished channels from the await-set, because if any channels in the await-set are finished, the processor will run again immediately. Numbers in this set correspond to positions in the FrameProcessor.inputChannels() list. It is OK to pass in a mutable set, because this method does not modify the set or retain a reference to it.

returnObject

public static <T> ReturnOrAwait<T> returnObject(T o)

Return a result.

value

@Nullable
public T value()

The returned result. Valid if isReturn() is true.

awaitSet

public it.unimi.dsi.fastutil.ints.IntSet awaitSet()

The set of channels the processors wants to wait for. Valid if isAwait() is true. Numbers in this set correspond to positions in the FrameProcessor.inputChannels() list.

isReturn

public boolean isReturn()

Whether the processor has returned a value. This is the opposite of isAwait().

isAwait

public boolean isAwait()

Whether the processor wants to be scheduled again. This is the opposite of isReturn().

isAwaitAll

public boolean isAwaitAll()

Whether the processor wants to wait for all channels in awaitSet() (true), or any channel (false)

equals

public boolean equals(Object o)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

toString

public String toString()

Overrides:

toString in class Object