sdk-api-kotlin/dev.restate.sdk.kotlin/WorkflowContext

WorkflowContext

sealed interface WorkflowContext : SharedWorkflowContext, ObjectContext

This interface can be used only within workflow handlers of workflow. It extends Context adding access to the workflow instance key-value state storage and to the DurablePromise API.

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

Functions

awakeable

abstract suspend fun <T : Any> awakeable(serde: Serde<T>): Awakeable<T>

Create an Awakeable, addressable through Awakeable.id.

awakeable

inline suspend fun <T : Any> Context.awakeable(): Awakeable<T>

Create an Awakeable using KtSerdes.json deserializer, addressable through Awakeable.id.

awakeableHandle

abstract fun awakeableHandle(id: String): AwakeableHandle

Create a new AwakeableHandle for the provided identifier. You can use it to AwakeableHandle.resolve or AwakeableHandle.reject the linked Awakeable.

call

open suspend fun <T, R> call(target: Target, inputSerde: Serde<T>, outputSerde: Serde<R>, parameter: T): R

Invoke another Restate service method and wait for the response. Same as call(methodDescriptor, parameter).await().

callAsync

abstract suspend fun <T, R> callAsync(target: Target, inputSerde: Serde<T>, outputSerde: Serde<R>, parameter: T): Awaitable<R>

Invoke another Restate service method.

clear

abstract suspend fun clear(key: StateKey<*>)

Clears the state stored under key.

clearAll

abstract suspend fun clearAll()

Clears all the state of this virtual object instance key-value state storage

get

abstract suspend fun <T : Any> get(key: StateKey<T>): T?

Gets the state stored under key, deserializing the raw value using the StateKey.serde.

key

abstract fun key(): String

promise

abstract fun <T : Any> promise(key: DurablePromiseKey<T>): DurablePromise<T>

Create a DurablePromise for the given key.

promiseHandle

abstract fun <T : Any> promiseHandle(key: DurablePromiseKey<T>): DurablePromiseHandle<T>

Create a new DurablePromiseHandle for the provided key. You can use it to DurablePromiseHandle.resolve or DurablePromiseHandle.reject the given DurablePromise.

random

abstract fun random(): RestateRandom

Create a RestateRandom instance inherently predictable, seeded on the dev.restate.sdk.common.InvocationId, which is not secret.

request

abstract fun request(): Request

runBlock

abstract suspend fun <T> runBlock(serde: Serde<T>, name: String = "", retryPolicy: RetryPolicy? = null, block: suspend () -> T): T

Execute a non-deterministic closure, recording the result value in the journal. The result value will be re-played in case of re-invocation (e.g. because of failure recovery or suspension point) without re-executing the closure. Use this feature if you want to perform non-deterministic operations.

runBlock

inline suspend fun <T : Any> Context.runBlock(name: String = "", retryPolicy: RetryPolicy? = null, noinline block: suspend () -> T): T

Execute a non-deterministic closure, recording the result value in the journal using KtSerdes.json. The result value will be re-played in case of re-invocation (e.g. because of failure recovery or suspension point) without re-executing the closure. Use this feature if you want to perform non-deterministic operations.

send

abstract suspend fun <T> send(target: Target, inputSerde: Serde<T>, parameter: T, delay: Duration = Duration.ZERO)

Invoke another Restate service without waiting for the response.

set

abstract suspend fun <T : Any> set(key: StateKey<T>, value: T)

Sets the given value under the given key, serializing the value using the StateKey.serde.

sleep

open suspend fun sleep(duration: Duration)

Causes the current execution of the function invocation to sleep for the given duration.

stateKeys

abstract suspend fun stateKeys(): Collection<String>

Gets all the known state keys for this virtual object instance.

timer

abstract suspend fun timer(duration: Duration): Awaitable<Unit>

Causes the start of a timer for the given duration. You can await on the timer end by invoking Awaitable.await.

WorkflowContext

See also

Functions