org.apache.flink.statefun.sdk.java

Interface Context

All Known Implementing Classes:

TestContext

public interface Context

A Context contains information about the current function invocation, such as the invoked function instance's and caller's Address. It is also used for side-effects as a result of the invocation such as send messages to other functions or egresses, and provides access to AddressScopedStorage scoped to the current Address.

Method Summary

Modifier and Type	Method and Description
java.util.Optional<Address>	caller()
void	cancelDelayedMessage(java.lang.String cancellationToken) Cancel a delayed message (a message that was send via sendAfter(Duration, Message)).
default java.util.concurrent.CompletableFuture<java.lang.Void>	done()
Address	self()
void	send(EgressMessage message) Sends out a EgressMessage to an egress.
void	send(Message message) Sends out a Message to another function.
void	sendAfter(java.time.Duration duration, Message message) Sends out a Message to another function, after a specified Duration delay.
void	sendAfter(java.time.Duration duration, java.lang.String cancellationToken, Message message) Sends out a Message to another function, after a specified Duration delay.
AddressScopedStorage	storage()

Method Detail

self

Address self()

Returns:

The current invoked function instance's Address.

caller

java.util.Optional<Address> caller()

Returns:

The caller function instance's Address, if applicable. This is Optional.empty() if the message was sent to this function via an ingress.

send

void send(Message message)

Sends out a Message to another function.

Parameters:

message - the message to send.

sendAfter

void sendAfter(java.time.Duration duration,
               Message message)

Sends out a Message to another function, after a specified Duration delay.

Parameters:

duration - the amount of time to delay the message delivery.

message - the message to send.

sendAfter

void sendAfter(java.time.Duration duration,
               java.lang.String cancellationToken,
               Message message)

Sends out a Message to another function, after a specified Duration delay.

Parameters:

duration - the amount of time to delay the message delivery. * @param cancellationToken

cancellationToken - the non-empty, non-null, unique token to attach to this message, to be used for message cancellation. (see cancelDelayedMessage(String).)

message - the message to send.

cancelDelayedMessage

void cancelDelayedMessage(java.lang.String cancellationToken)

Cancel a delayed message (a message that was send via sendAfter(Duration, Message)).

NOTE: this is a best-effort operation, since the message might have been already delivered. If the message was delivered, this is a no-op operation.

Parameters:

cancellationToken - the id of the message to un-send.

send

void send(EgressMessage message)

Sends out a EgressMessage to an egress.

Parameters:

message - the message to send.

storage

AddressScopedStorage storage()

Returns:

The AddressScopedStorage, providing access to stored values scoped to the current invoked function instance's Address (which is obtainable using self()).

done

default java.util.concurrent.CompletableFuture<java.lang.Void> done()