de.otto.synapse.channel

Class StopCondition

java.lang.Object

de.otto.synapse.channel.StopCondition

public final class StopCondition
extends java.lang.Object

Conditions used in receiver endpoints to specify under which circumstances message consumption should stop.

Method Summary

Modifier and Type	Method and Description
static java.util.function.Predicate<ShardResponse>	arrivalTimestampAfterNow() Returns a stop condition that is true if at least one message contained in the ShardResponse has arrived after creating the predicate.
static java.util.function.Predicate<ShardResponse>	arrivalTimestampAfterNow(java.time.Clock clock) Returns a stop condition that is true if at least one message contained in the ShardResponse has arrived after creating the predicate.
static java.util.function.Predicate<ShardResponse>	emptyResponse() Returns a stop condition that is true if the ShardResponse does not contain any messages.
static java.util.function.Predicate<ShardResponse>	endOfChannel() Returns a stop condition that is true if the end-of-channel is reached.
static java.util.function.Predicate<ShardResponse>	shutdown() Do not stop message consumption until the application is shutting down.
static java.util.function.Predicate<ShardResponse>	timestamp(java.time.Instant timestamp) Returns a stop condition that is true after the given timestamp.
static java.util.function.Predicate<ShardResponse>	timestamp(java.time.Instant timestamp, java.time.Clock clock) Returns a stop condition that is true after the given timestamp.

Methods inherited from class java.lang.Object

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

Method Detail

shutdown

public static java.util.function.Predicate<ShardResponse> shutdown()

Do not stop message consumption until the application is shutting down.

Returns:

stop condition always returning false;

timestamp

public static java.util.function.Predicate<ShardResponse> timestamp(java.time.Instant timestamp)

Returns a stop condition that is true after the given timestamp.

Parameters:

timestamp - the point in time after which the predicate will return true.

Returns:

stop condition

timestamp

public static java.util.function.Predicate<ShardResponse> timestamp(java.time.Instant timestamp,
                                                                    java.time.Clock clock)

Returns a stop condition that is true after the given timestamp.

Parameters:

timestamp - the point in time after which the predicate will return true.

clock - the clock used to get the current time

Returns:

stop condition

arrivalTimestampAfterNow

public static java.util.function.Predicate<ShardResponse> arrivalTimestampAfterNow()

Returns a stop condition that is true if at least one message contained in the ShardResponse has arrived after creating the predicate.

Returns:

stop condition

arrivalTimestampAfterNow

public static java.util.function.Predicate<ShardResponse> arrivalTimestampAfterNow(java.time.Clock clock)

Returns a stop condition that is true if at least one message contained in the ShardResponse has arrived after creating the predicate.

Parameters:

clock - the clock used to get the current time

Returns:

stop condition

endOfChannel

public static java.util.function.Predicate<ShardResponse> endOfChannel()

Returns a stop condition that is true if the end-of-channel is reached.

It is assumed that end-of-channel is reached if ShardResponse.getDurationBehind() is Duration.ZERO, even if ShardResponse.getMessages() is not empty.

Note that using this predicate as a stop condition for sharded message logs, the message consumption will stop after all shards have reached the end of the channels at least once.

Returns:

stop condition

emptyResponse

public static java.util.function.Predicate<ShardResponse> emptyResponse()

Returns a stop condition that is true if the ShardResponse does not contain any messages.

An empty ShardResponse does not necessarily indicate that the end-of-channel is reached. Especially in case of Kinesis message logs it is possible that multiple ShardResponses contain no messages, while the ShardResponse.getDurationBehind() is greater ZERO.

You might want to combine this predicate with endOfChannel() like this:

     StopCondition.endOfChannel().and(StopCondition.emptyResponse());
 

Note that using this predicate as a stop condition for sharded message logs, the message consumption will stop after all shards have reached the end of the channels at least once.

Returns:

stop condition