Module io.axoniq.connector.axonserver

Package io.axoniq.axonserver.connector.impl

Class AbstractBufferedStream<T,R>

java.lang.Object

io.axoniq.axonserver.connector.impl.FlowControlledStream<T,R>

io.axoniq.axonserver.connector.impl.FlowControlledBuffer<T,R>

io.axoniq.axonserver.connector.impl.AbstractBufferedStream<T,R>

Type Parameters:

T - the type of results this stream implementation buffers

R - the type of message used for flow control on this stream

All Implemented Interfaces:

ResultStream<T>, io.grpc.stub.ClientResponseObserver<R,T>, io.grpc.stub.StreamObserver<T>, AutoCloseable

Direct Known Subclasses:

BufferedEventStream, BufferedPersistentStreamSegment, SubscriptionQueryUpdateBuffer

public abstract class AbstractBufferedStream<T,R>
extends FlowControlledBuffer<T,R>
implements ResultStream<T>

An abstract FlowControlledBuffer and ResultStream implementation, used to provide a buffered stream of results of T when receiving a request of type R.

Constructor Summary

Constructors

Constructor	Description
AbstractBufferedStream(String clientId, int bufferSize, int refillBatch)	Constructs an AbstractBufferedStream

Method Summary

Modifier and Type	Method	Description
void	close()	Requests the current stream to be closed.
Optional<Throwable>	getError()	Returns an optional containing the exception reported by the Server, if any.
boolean	isClosed()	Check whether this buffer has been closed off
T	next()	Consumes the next available element in the stream, waiting for an element to become available, or for the buffer to be closed.
T	nextIfAvailable()	Consumes the next available element in the stream, if available.
T	nextIfAvailable(long timeout, TimeUnit unit)	Consumes the next available element in the stream, waiting for at most timeout (in given unit) for an element to become available.
void	onAvailable(Runnable callback)	Sets the given callback to execute when data is available for reading, or the stream has been closed.
void	onCloseRequested(Runnable handler)	Adds the given handler to a collection of Runnables to be invoked when the stream is closed by the server.
void	onCompleted()
void	onError(Throwable t)
void	onNext(T value)
T	peek()	Retrieves, but does not remove, the first entry of this buffer, or returns null if the buffer is empty.

Methods inherited from class io.axoniq.axonserver.connector.impl.FlowControlledBuffer

beforeStart, getErrorResult, take, terminalMessage, tryTake, tryTake, tryTake, tryTakeNow

Methods inherited from class io.axoniq.axonserver.connector.impl.FlowControlledStream

buildFlowControlMessage, buildInitialFlowControlMessage, enableFlowControl, markConsumed, outboundStream

Methods inherited from class java.lang.Object

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

Constructor Detail

AbstractBufferedStream

public AbstractBufferedStream(String clientId,
                              int bufferSize,
                              int refillBatch)

Constructs an AbstractBufferedStream

Parameters:

clientId - the identifier of the client initiation this stream

bufferSize - the size of this buffer

refillBatch - the number of entries to be consumed prior to refilling this buffer

Method Detail

next

public T next()
       throws InterruptedException

Description copied from interface: ResultStream

Consumes the next available element in the stream, waiting for an element to become available, or for the buffer to be closed.

Specified by:

next in interface ResultStream<T>

Returns:

the next available element in the stream, or null if none available

Throws:

InterruptedException - when the Thread is interrupted while waiting for an element to become available

See Also:

ResultStream.isClosed()

nextIfAvailable

public T nextIfAvailable()

Description copied from interface: ResultStream

Consumes the next available element in the stream, if available. Will return null if no element is available immediately.

Specified by:

nextIfAvailable in interface ResultStream<T>

Returns:

the next available element in the stream, or null if none is available, or if the stream is closed

nextIfAvailable

public T nextIfAvailable(long timeout,
                         TimeUnit unit)
                  throws InterruptedException

Description copied from interface: ResultStream

Consumes the next available element in the stream, waiting for at most timeout (in given unit) for an element to become available. If no element is available with the given timeout, or if the stream has been closed, it returns null.

Specified by:

nextIfAvailable in interface ResultStream<T>

Parameters:

timeout - the amount of time to wait for an element to become available

unit - the unit of time in which the timeout is expressed

Returns:

the next available element in the stream, or null if none is available

Throws:

InterruptedException - when the Thread is interrupted while waiting for an element to become available

See Also:

ResultStream.isClosed()

onNext

public void onNext(T value)

Specified by:

onNext in interface io.grpc.stub.StreamObserver<T>

Overrides:

onNext in class FlowControlledBuffer<T,R>

onError

public void onError(Throwable t)

Specified by:

onError in interface io.grpc.stub.StreamObserver<T>

Overrides:

onError in class FlowControlledBuffer<T,R>

getError

public Optional<Throwable> getError()

Description copied from interface: ResultStream

Returns an optional containing the exception reported by the Server, if any.

Note that this method may return a non-empty response, even when ResultStream.isClosed() returns false, or if there are messages available for processing.

Specified by:

getError in interface ResultStream<T>

Returns:

an optional containing the exception reported by the Server, if any.

onCompleted

public void onCompleted()

Specified by:

onCompleted in interface io.grpc.stub.StreamObserver<T>

Overrides:

onCompleted in class FlowControlledBuffer<T,R>

peek

public T peek()

Description copied from class: FlowControlledBuffer

Retrieves, but does not remove, the first entry of this buffer, or returns null if the buffer is empty.

Specified by:

peek in interface ResultStream<T>

Overrides:

peek in class FlowControlledBuffer<T,R>

Returns:

the first entry of this buffer without removing it, or null if it is empty

onAvailable

public void onAvailable(Runnable callback)

Description copied from interface: ResultStream

Sets the given callback to execute when data is available for reading, or the stream has been closed. Note that any registration will replace the previous one.

The callback is invoked in the publisher's thread. Invocations should be as short as possible, preferably delegating to a reader thead, instead of accessing the entries directly.

Specified by:

onAvailable in interface ResultStream<T>

Parameters:

callback - a {Runnable} to Runnable.run() when the next entry becomes available or null to disable callbacks

isClosed

public boolean isClosed()

Description copied from class: FlowControlledBuffer

Check whether this buffer has been closed off

Specified by:

isClosed in interface ResultStream<T>

Overrides:

isClosed in class FlowControlledBuffer<T,R>

Returns:

true if this buffer is closed, false otherwise

See Also:

ResultStream.getError()

close

public void close()

Description copied from interface: ResultStream

Requests the current stream to be closed. It is up to the publishing end of the stream to honor the request.

Any elements received before closing are still available for reading.

Specified by:

close in interface AutoCloseable

Specified by:

close in interface ResultStream<T>

Overrides:

close in class FlowControlledBuffer<T,R>

onCloseRequested

public void onCloseRequested(Runnable handler)

Adds the given handler to a collection of Runnables to be invoked when the stream is closed by the server. Note that data may still be buffered locally for processing.

Parameters:

handler - Runnable to invoke when the stream is closed by the server