org.axonframework.axonserver.connector.event.axon

Class EventBuffer

java.lang.Object

org.axonframework.axonserver.connector.event.axon.EventBuffer

All Implemented Interfaces:

AutoCloseable, BlockingStream<TrackedEventMessage<?>>, TrackingEventStream

public class EventBuffer
extends Object
implements TrackingEventStream

Client-side buffer of messages received from the server. Once consumed from this buffer, the client is notified of a permit being consumed, potentially triggering a permit refresh, if flow control is enabled.

This class is intended for internal use. Be cautious.

Author:

Marc Gathier, Allard Buijze

Constructor Summary

Constructors

Constructor and Description
EventBuffer(EventUpcaster upcasterChain, Serializer serializer) Initializes an Event Buffer, passing messages through given upcasterChain and deserializing events using given serializer.
EventBuffer(EventUpcaster upcasterChain, Serializer serializer, long pollingTimeMillis) Initializes an Event Buffer, passing messages through given upcasterChain and deserializing events using given serializer.

Method Summary

Modifier and Type	Method and Description
void	blacklist(TrackedEventMessage<?> trackedEventMessage) Report the stream that a specific message was ignored by the consumer.
void	close()
void	fail(RuntimeException e) Fail this EventBuffer with the given RuntimeException.
boolean	hasNextAvailable(int timeout, TimeUnit timeUnit) Checks whether or not the next message in the stream is available.
TrackedEventMessage<?>	nextAvailable() Returns the next available message in the stream.
Optional<TrackedEventMessage<?>>	peek() Checks whether or not the next message in the stream is immediately available.
boolean	push(EventWithToken event) Push a new event on to this EventBuffer instance.
void	registerBlacklistListener(Consumer<SerializedType> blacklistListener) Registers the callback to invoke when a the event processor determines that a type should be blacklisted.
void	registerCloseListener(Consumer<EventBuffer> closeCallback) Registers the callback to invoke when the reader wishes to close the stream.
void	registerConsumeListener(Consumer<Integer> consumeListener) Registers the callback to invoke when a raw input message was consumed from the buffer.

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.axonframework.common.stream.BlockingStream

asStream, hasNextAvailable

Constructor Detail

EventBuffer

public EventBuffer(EventUpcaster upcasterChain,
                   Serializer serializer)

Initializes an Event Buffer, passing messages through given upcasterChain and deserializing events using given serializer.

Parameters:

upcasterChain - the upcasterChain to translate serialized representations before deserializing

serializer - the serializer capable of deserializing incoming messages

EventBuffer

public EventBuffer(EventUpcaster upcasterChain,
                   Serializer serializer,
                   long pollingTimeMillis)

Initializes an Event Buffer, passing messages through given upcasterChain and deserializing events using given serializer.

Parameters:

upcasterChain - the upcasterChain to translate serialized representations before deserializing

serializer - the serializer capable of deserializing incoming messages

pollingTimeMillis - a long defining the polling periods used to split the up the timeout used in hasNextAvailable(int, TimeUnit), ensuring nobody accidentally blocks for an extended period of time. Defaults to 500 milliseconds

Method Detail

blacklist

public void blacklist(TrackedEventMessage<?> trackedEventMessage)

Report the stream that a specific message was ignored by the consumer. Stream implementation can use this information for instance to blacklist similar messages. ----

This implementation blacklists based on the payload type of the given message.

Specified by:

blacklist in interface BlockingStream<TrackedEventMessage<?>>

Parameters:

trackedEventMessage - the message containing the payload to blacklist

registerCloseListener

public void registerCloseListener(Consumer<EventBuffer> closeCallback)

Registers the callback to invoke when the reader wishes to close the stream.

Parameters:

closeCallback - The callback to invoke when the reader wishes to close the stream

registerConsumeListener

public void registerConsumeListener(Consumer<Integer> consumeListener)

Registers the callback to invoke when a raw input message was consumed from the buffer. Note that there can only be one listener registered.

Parameters:

consumeListener - the callback to invoke when a raw input message was consumed from the buffer

registerBlacklistListener

public void registerBlacklistListener(Consumer<SerializedType> blacklistListener)

Registers the callback to invoke when a the event processor determines that a type should be blacklisted. Note that there can only be one listener registered.

Parameters:

blacklistListener - the callback to invoke when a payload type is to be blacklisted.

peek

public Optional<TrackedEventMessage<?>> peek()

Description copied from interface: BlockingStream

Checks whether or not the next message in the stream is immediately available. If so, an Optional with the next message is returned (without moving the stream pointer), otherwise an empty Optional is returned.

Specified by:

peek in interface BlockingStream<TrackedEventMessage<?>>

Returns:

the next event if immediately available

hasNextAvailable

public boolean hasNextAvailable(int timeout,
                                TimeUnit timeUnit)
                         throws InterruptedException

Description copied from interface: BlockingStream

Checks whether or not the next message in the stream is available. If a message is available when this method is invoked this method returns immediately. If not, this method will block until a message becomes available, returning true or until the given timeout expires, returning false.

To check if the stream has messages available now, pass a zero timeout.

Specified by:

hasNextAvailable in interface BlockingStream<TrackedEventMessage<?>>

Parameters:

timeout - the maximum number of time units to wait for messages to become available

timeUnit - the time unit for the timeout

Returns:

true if a message is available or becomes available before the given timeout, false otherwise

Throws:

InterruptedException - when the thread is interrupted before the indicated time is up

nextAvailable

public TrackedEventMessage<?> nextAvailable()

Description copied from interface: BlockingStream

Returns the next available message in the stream. Note that this method blocks for as long as there are no available messages in the stream. In case this blocking behavior is not desired use BlockingStream.hasNextAvailable() with or without a timeout to check if the stream has available messages before calling this method.

Specified by:

nextAvailable in interface BlockingStream<TrackedEventMessage<?>>

Returns:

the next available message

close

public void close()

Specified by:

close in interface AutoCloseable

Specified by:

close in interface BlockingStream<TrackedEventMessage<?>>

push

public boolean push(EventWithToken event)

Push a new event on to this EventBuffer instance. Will return false if the given event could not be added because the buffer is already closed or if the operation was interrupted. If pushing the event was successful, true will be returned.

Parameters:

event - the EventWithToken to be pushed on to this EventBuffer

Returns:

true if adding the event to the buffer was successful and false if it wasn't

fail

public void fail(RuntimeException e)

Fail this EventBuffer with the given RuntimeException.

Parameters:

e - a RuntimeException with which this EventBuffer failed