io.simplesource.saga.action.async

Class AsyncSpec<A,D,K,O,R>

java.lang.Object

io.simplesource.saga.action.async.AsyncSpec<A,D,K,O,R>

Type Parameters:

A - common representation form for all action commands (typically Json / GenericRecord for Avro)

D - intermediate decoded input type (this can be specific to this action processor)

K - key for the value topic

O - value returned by async function

R - final result type that ends up in value topic

public final class AsyncSpec<A,D,K,O,R>
extends Object

A value class with the information required to define an async action processor.

This includes:

• The conversion from the shared type A to the decode input type D.
• The asynchronous function itself.
• An undo (compensation) action if there is one.
• The conversion to an output result type, if serialized output is required
• The serdes for serialisation to the output topic

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	AsyncSpec.UndoFunction<A,D,O> The UndoFunction is a mechanism to take the result of the async invocation and turn it into an undo action command.

Field Summary

Fields

Modifier and Type	Field and Description
String	actionType Each action processor must have a unique action type associated with it.
java.util.function.BiConsumer<D,Callback<O>>	asyncFunction This is a BiConsumer that takes the decoded input type and a Callback as input.
String	groupId This group Id is used to create a consumer group that consumes requests to invoke asynchronous actions.
java.util.function.Function<A,io.simplesource.data.Result<Throwable,D>>	inputDecoder The Input decoder converts the common action command representation to an intermediate decoded type.
Optional<AsyncResult<D,K,O,R>>	resultSpec This is required for cases where the result is written to an output topic, or where an undo function is defined based on the return value.
Optional<java.time.Duration>	timeout The timeout.
AsyncSpec.UndoFunction<A,D,O>	undoFunction An undo function.

Constructor Summary

Constructors

Constructor and Description
AsyncSpec()

Method Summary

Methods inherited from class java.lang.Object

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

Field Detail

actionType

public final String actionType

Each action processor must have a unique action type associated with it.

inputDecoder

public final java.util.function.Function<A,io.simplesource.data.Result<Throwable,D>> inputDecoder

The Input decoder converts the common action command representation to an intermediate decoded type. The A type is common across all action processors and action types. This enables working with a type that is specific to this action processor.

asyncFunction

public final java.util.function.BiConsumer<D,Callback<O>> asyncFunction

This is a BiConsumer that takes the decoded input type and a Callback as input. It then executes and, completes the call back when it is finished.

groupId

public final String groupId

This group Id is used to create a consumer group that consumes requests to invoke asynchronous actions. This consumer group ensures that the load of submitting async actions actions is distributed across instances.

resultSpec

public final Optional<AsyncResult<D,K,O,R>> resultSpec

This is required for cases where the result is written to an output topic, or where an undo function is defined based on the return value.

undoFunction

public final AsyncSpec.UndoFunction<A,D,O> undoFunction

An undo function.

timeout

public final Optional<java.time.Duration> timeout

The timeout.

Constructor Detail

AsyncSpec

public AsyncSpec()