Package dev.restate.sdk

Class DurableFuture<T>

java.lang.Object

dev.restate.sdk.DurableFuture<T>

Type Parameters:

T - type of the future result

Direct Known Subclasses:

Awakeable, CallDurableFuture, Select

public abstract class DurableFuture<T>
extends Object

A DurableFuture allows to await an asynchronous result. Once await() is called, the execution stops until the asynchronous result is available.

The result can be either a success or a failure. In case of a failure, await() will throw a TerminalException.

NOTE: This interface MUST NOT be accessed concurrently since it can lead to different orderings of user actions, corrupting the execution of the invocation.

Constructor Summary

Constructors

Constructor	Description
DurableFuture()

Method Summary

Modifier and Type	Method	Description
static DurableFuture<Void>	all(DurableFuture<?> first, DurableFuture<?> second, DurableFuture<?>... others)	Create an DurableFuture that awaits all the given futures.
static DurableFuture<Void>	all(List<DurableFuture<?>> durableFutures)	Create an DurableFuture that awaits all the given futures.
static DurableFuture<Integer>	any(DurableFuture<?> first, DurableFuture<?> second, DurableFuture<?>... others)	Create an DurableFuture that awaits any of the given futures.
static DurableFuture<Integer>	any(List<DurableFuture<?>> durableFutures)	Create an DurableFuture that awaits any of the given futures.
protected abstract AsyncResult<T>	asyncResult()
final T	await()	Wait for this DurableFuture to complete.
final T	await(Duration timeout)	Same as await(), but throws a TimeoutException if this DurableFuture doesn't complete before the provided timeout.
final <U> DurableFuture<U>	map(ThrowingFunction<T,U> mapper)	Map the success result of this DurableFuture.
final <U> DurableFuture<U>	map(ThrowingFunction<T,U> successMapper, ThrowingFunction<TerminalException,U> failureMapper)	Map both the success and the failure result of this DurableFuture.
final DurableFuture<T>	mapFailure(ThrowingFunction<TerminalException,T> failureMapper)	Map the failure result of this DurableFuture.
protected abstract Executor	serviceExecutor()
final DurableFuture<T>	withTimeout(Duration timeout)

Methods inherited from class java.lang.Object

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

Constructor Details

DurableFuture

public DurableFuture()

Method Details

asyncResult

protected abstract AsyncResult<T> asyncResult()

serviceExecutor

protected abstract Executor serviceExecutor()

await

public final T await()
              throws TerminalException

Wait for this DurableFuture to complete.

Executing this method may trigger the suspension of the function.

NOTE: You should never wrap this function in a try-catch catching Throwable, as it will catch AbortedExecutionException as well, which will prevent the service invocation to orderly suspend.

Throws:

TerminalException - if this future was completed with a failure

await

public final T await(Duration timeout)
              throws TerminalException

Same as await(), but throws a TimeoutException if this DurableFuture doesn't complete before the provided timeout.

Throws:

TerminalException

withTimeout

public final DurableFuture<T> withTimeout(Duration timeout)

Returns:

a DurableFuture that throws a TimeoutException if this future doesn't complete before the provided timeout.

map

public final <U> DurableFuture<U> map(ThrowingFunction<T,U> mapper)

Map the success result of this DurableFuture.

Parameters:

mapper - the mapper to execute if this DurableFuture completes with success. The mapper can throw a TerminalException, thus failing the resulting DurableFuture.

Returns:

a new DurableFuture with the mapped result, when completed

map

public final <U> DurableFuture<U> map(ThrowingFunction<T,U> successMapper,
 ThrowingFunction<TerminalException,U> failureMapper)

Map both the success and the failure result of this DurableFuture.

Parameters:

successMapper - the mapper to execute if this DurableFuture completes with success. The mapper can throw a TerminalException, thus failing the resulting DurableFuture.

failureMapper - the mapper to execute if this DurableFuture completes with failure. The mapper can throw a TerminalException, thus failing the resulting DurableFuture.

Returns:

a new DurableFuture with the mapped result, when completed

mapFailure

public final DurableFuture<T> mapFailure(ThrowingFunction<TerminalException,T> failureMapper)

Map the failure result of this DurableFuture.

Parameters:

failureMapper - the mapper to execute if this DurableFuture completes with failure. The mapper can throw a TerminalException, thus failing the resulting DurableFuture.

Returns:

a new DurableFuture with the mapped result, when completed

any

public static DurableFuture<Integer> any(DurableFuture<?> first,
 DurableFuture<?> second,
 DurableFuture<?>... others)

Create an DurableFuture that awaits any of the given futures. The resulting DurableFuture returns the index of the completed future in the provided list.

See Also:

• Select

any

public static DurableFuture<Integer> any(List<DurableFuture<?>> durableFutures)

Create an DurableFuture that awaits any of the given futures. The resulting DurableFuture returns the index of the completed future in the provided list.

An empty list is not supported and will throw IllegalArgumentException.

See Also:

• Select

all

public static DurableFuture<Void> all(DurableFuture<?> first,
 DurableFuture<?> second,
 DurableFuture<?>... others)

Create an DurableFuture that awaits all the given futures.

The behavior is the same as CompletableFuture.allOf(CompletableFuture[]).

all

public static DurableFuture<Void> all(List<DurableFuture<?>> durableFutures)

Create an DurableFuture that awaits all the given futures.

An empty list is not supported and will throw IllegalArgumentException.

The behavior is the same as CompletableFuture.allOf(CompletableFuture[]).