Class UmaDbAsyncClientImpl

java.lang.Object

io.umadb.client.grpc.UmaDbAsyncClientImpl

All Implemented Interfaces:

UmaDbAsyncClient, AutoCloseable

public final class UmaDbAsyncClientImpl
extends Object
implements UmaDbAsyncClient

Internal gRPC-based implementation of UmaDbAsyncClient.

Unary calls go through the asynchronous stub rather than the futures stub: the futures stub hands back a Guava ListenableFuture, which would both leak Guava into the public API and give no way to make cancellation reach the wire. Driving the async stub inside a Context.CancellableContext solves both, and uses the same cancellation mechanism as the streaming calls.

This class is not intended to be used directly by client code. Clients should construct instances via UmaDbClientBuilder.buildAsync().

Constructor Summary

Constructors

Constructor	Description
UmaDbAsyncClientImpl(String host, int port, boolean tlsEnabled, String caFilePath, String apiKey, Executor executor)	Creates a new asynchronous client implementation.

Method Summary

Modifier and Type	Method	Description
void	connect()	Establishes a connection to the UmaDB server.
CompletableFuture<Long>	getHeadPosition()	Returns the position of the most recent event in the event store.
CompletableFuture<Optional<Long>>	getTrackingInfo(String source)	Returns the last recorded position for a named source.
CompletableFuture<AppendResponse>	handle(AppendRequest appendRequest)	Appends events to the event store.
UmaDbStream	handle(ReadRequest readRequest, UmaDbStreamObserver<ReadResponse> observer)	Reads events, delivering each batch to the given observer.
void	shutdown()	Shuts the client down, cancelling any live streams and closing the connection.
UmaDbStream	subscribe(SubscribeRequest subscribeRequest, UmaDbStreamObserver<SubscribeResponse> observer)	Opens a continuous subscription, delivering each batch to the given observer.

Methods inherited from class Object

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

Methods inherited from interface UmaDbAsyncClient

close

Constructor Details

UmaDbAsyncClientImpl

public UmaDbAsyncClientImpl(String host,
 int port,
 boolean tlsEnabled,
 String caFilePath,
 String apiKey,
 Executor executor)

Creates a new asynchronous client implementation.

Parameters:

host - UmaDB server host

port - UmaDB server port

tlsEnabled - indicates whether an encrypted communication (TLS) is to be used

caFilePath - optional path to a CA certificate for TLS

apiKey - optional API key (requires TLS)

executor - optional executor for gRPC callbacks; null uses the gRPC default

Throws:

IllegalArgumentException - if arguments are invalid or insecure

Method Details

connect

public void connect()

Description copied from interface: UmaDbAsyncClient

Establishes a connection to the UmaDB server.

This method must be called before performing any operations. It is idempotent.

Specified by:

connect in interface UmaDbAsyncClient

handle

public CompletableFuture<AppendResponse> handle(AppendRequest appendRequest)

Description copied from interface: UmaDbAsyncClient

Appends events to the event store.

Specified by:

handle in interface UmaDbAsyncClient

Parameters:

appendRequest - the request describing the events to append

Returns:

a future completing with the position of the last appended event, or completing exceptionally with a UmaDbException cause

getHeadPosition

public CompletableFuture<Long> getHeadPosition()

Description copied from interface: UmaDbAsyncClient

Returns the position of the most recent event in the event store.

Specified by:

getHeadPosition in interface UmaDbAsyncClient

Returns:

a future completing with the sequence number of the latest event

getTrackingInfo

public CompletableFuture<Optional<Long>> getTrackingInfo(String source)

Description copied from interface: UmaDbAsyncClient

Returns the last recorded position for a named source.

Specified by:

getTrackingInfo in interface UmaDbAsyncClient

Parameters:

source - the unique identifier of the consumer or projection

Returns:

a future completing with the position the source has processed up to, or Optional.empty() if no tracking info exists for it

handle

public UmaDbStream handle(ReadRequest readRequest,
 UmaDbStreamObserver<ReadResponse> observer)

Description copied from interface: UmaDbAsyncClient

Reads events, delivering each batch to the given observer.

The stream ends, with UmaDbStreamObserver.onCompleted(), once the head position captured when the request was received has been reached. To keep receiving events as they are appended, use UmaDbAsyncClient.subscribe(SubscribeRequest, UmaDbStreamObserver) instead.

Specified by:

handle in interface UmaDbAsyncClient

Parameters:

readRequest - the request describing which events to read

observer - receives the batches; must not be null

Returns:

a handle for controlling demand and cancelling the stream

subscribe

public UmaDbStream subscribe(SubscribeRequest subscribeRequest,
 UmaDbStreamObserver<SubscribeResponse> observer)

Description copied from interface: UmaDbAsyncClient

Opens a continuous subscription, delivering each batch to the given observer.

The subscription replays already-recorded events matching the request and then continues to deliver new events as they are appended. It does not end on its own — call UmaDbStream.cancel() or UmaDbAsyncClient.shutdown() to stop it.

Specified by:

subscribe in interface UmaDbAsyncClient

Parameters:

subscribeRequest - the request describing which events to subscribe to

observer - receives the batches; must not be null

Returns:

a handle for controlling demand and cancelling the subscription

shutdown

public void shutdown()

Description copied from interface: UmaDbAsyncClient

Shuts the client down, cancelling any live streams and closing the connection.

Idempotent. After calling this the client should not be used again; further calls fail through the returned future or the observer rather than by throwing.

Specified by:

shutdown in interface UmaDbAsyncClient