io.spine.server.delivery

Class DeliveryStrategy

java.lang.Object

io.spine.server.delivery.DeliveryStrategy

Direct Known Subclasses:

UniformAcrossAllShards

public abstract class DeliveryStrategy
extends java.lang.Object

Determines the index of a shard for the given identifier of an entity.

The idea is to avoid the concurrent modification of the same Entity instance on several app nodes. Therefore an entity is put into a shard, which in turn is designed to process all the shard-incoming messages on a single application node at a time.

Constructor Summary

Constructors

Constructor and Description
DeliveryStrategy()

Method Summary

Modifier and Type	Method and Description
io.spine.server.delivery.ShardIndex	determineIndex(java.lang.Object entityId, io.spine.type.TypeUrl entityStateType)
protected abstract io.spine.server.delivery.ShardIndex	indexFor(java.lang.Object entityId, io.spine.type.TypeUrl entityStateType) Determines the shard index for the messages heading to the entity with the specified target identifier.
protected abstract int	shardCount() Tells how many shards there are according to this strategy.

Methods inherited from class java.lang.Object

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

Constructor Detail

DeliveryStrategy

public DeliveryStrategy()

Method Detail

indexFor

protected abstract io.spine.server.delivery.ShardIndex indexFor(java.lang.Object entityId,
                                                                io.spine.type.TypeUrl entityStateType)

Determines the shard index for the messages heading to the entity with the specified target identifier.

Parameters:

entityId - the identifier of the entity, to which the messages are dispatched

entityStateType - the type URL of the entity, to which the messages are dispatched

Returns:

the shard index

shardCount

protected abstract int shardCount()

Tells how many shards there are according to this strategy.

Returns:

total count of shards

determineIndex

public final io.spine.server.delivery.ShardIndex determineIndex(java.lang.Object entityId,
                                                                io.spine.type.TypeUrl entityStateType)