de.otto.synapse.endpoint.receiver

Interface MessageLogReceiverEndpoint

All Superinterfaces:

MessageEndpoint, MessageReceiverEndpoint

All Known Implementing Classes:

AbstractMessageLogReceiverEndpoint, DelegateMessageLogReceiverEndpoint

public interface MessageLogReceiverEndpoint
extends MessageReceiverEndpoint

Receiver-side MessageEndpoint endpoint of a Message Channel that matches random-access like reading of messages using ChannelPositions.

MessageLogReceiverEndpoints are endpoints for Publish-Subscribe Channels:

See Also:

EIP: Publish-Subscribe Channel

Method Summary

Modifier and Type	Method and Description
default java.util.concurrent.CompletableFuture<ChannelPosition>	consume(ChannelPosition startFrom) Beginning at the startFrom position, messages are consumed from the message log, until the stopCondition is true.
java.util.concurrent.CompletableFuture<ChannelPosition>	consumeUntil(ChannelPosition startFrom, java.util.function.Predicate<ShardResponse> stopCondition) Beginning at the startFrom position, messages are consumed from the message log, until the stopCondition is true.
void	stop() Stops consumption of messages and shuts down the MessageLogReceiverEndpoint.

Methods inherited from interface de.otto.synapse.endpoint.receiver.MessageReceiverEndpoint

getMessageDispatcher, register

Methods inherited from interface de.otto.synapse.endpoint.MessageEndpoint

getChannelName, getEndpointType, getInterceptorChain, intercept

Method Detail

consume

@Nonnull
default java.util.concurrent.CompletableFuture<ChannelPosition> consume(@Nonnull
                                                                                 ChannelPosition startFrom)

Beginning at the startFrom position, messages are consumed from the message log, until the stopCondition is true.

Takes zero or more messages from the channel, calls MessageEndpoint.intercept(Message) for every message, and notifies the registered consumers with the intercepted message, or drops the message, if intercept returns null.

Consumption starts with the first message after startFrom and finishes when either the stopCondition is met, or the application is shutting down.

The returned ChannelPosition is the position of the last message that was processed by the MessageLogReceiverEndpoint - whether it was dropped or consumed.

The registered consumers are used as a callback for consumed messages. A MessageDispatcher can be used as a consumer, if multiple consumers, or consumers with message payloads other than String are required.

Parameters:

startFrom - the start position used to proceed message consumption

Returns:

ChannelPosition

consumeUntil

@Nonnull
java.util.concurrent.CompletableFuture<ChannelPosition> consumeUntil(@Nonnull
                                                                              ChannelPosition startFrom,
                                                                              @Nonnull
                                                                              java.util.function.Predicate<ShardResponse> stopCondition)

Beginning at the startFrom position, messages are consumed from the message log, until the stopCondition is true.

If the message-log is sharded, the predicate must be true for every shard: otherwise, message consumption would continue on other shards.

Takes zero or more messages from the channel, calls MessageEndpoint.intercept(Message) for every message, and notifies the registered consumers with the intercepted message, or drops the message, if intercept returns null.

Consumption starts with the first message after startFrom and finishes when either the stopCondition is met, or the application is shutting down.

The returned ChannelPosition is the position of the last message that was processed by the MessageLogReceiverEndpoint - whether it was dropped or consumed.

The registered consumers are used as a callback for consumed messages. A MessageDispatcher can be used as a consumer, if multiple consumers, or consumers with message payloads other than String are required.

Parameters:

startFrom - the start position used to proceed message consumption

stopCondition - the predicate used to test if message consumption should be stopped. In most cases, the predicates defined in StopCondition should be sufficient.

Returns:

ChannelPosition

stop

void stop()

Stops consumption of messages and shuts down the MessageLogReceiverEndpoint.