Package org.elasticsearch.cluster

Interface ClusterState.FeatureAware

All Known Subinterfaces:

ClusterState.Custom, MetaData.Custom, PersistentTaskParams

All Known Implementing Classes:

IndexGraveyard, IngestMetadata, PersistentTasksCustomMetaData, RepositoriesMetaData, RestoreInProgress, ScriptMetaData, SnapshotDeletionsInProgress, SnapshotsInProgress

Enclosing class:

ClusterState

public static interface ClusterState.FeatureAware

An interface that implementors use when a class requires a client to maybe have a feature.

Method Summary

Modifier and Type	Method	Description
default java.util.Optional<java.lang.String>	getRequiredFeature()	An optional feature that is required for the client to have.
static <T extends VersionedNamedWriteable & ClusterState.FeatureAware> boolean	shouldSerialize(StreamOutput out, T custom)	Tests whether or not the custom should be serialized.

Method Detail

getRequiredFeature

default java.util.Optional<java.lang.String> getRequiredFeature()

An optional feature that is required for the client to have.

Returns:

an empty optional if no feature is required otherwise a string representing the required feature

shouldSerialize

static <T extends VersionedNamedWriteable & ClusterState.FeatureAware> boolean shouldSerialize(StreamOutput out,
                                                                                               T custom)

Tests whether or not the custom should be serialized. The criteria are:

• the output stream must be at least the minimum supported version of the custom
• the output stream must have the feature required by the custom (if any) or not be a transport client

That is, we only serialize customs to clients than can understand the custom based on the version of the client and the features that the client has. For transport clients we can be lenient in requiring a feature in which case we do not send the custom but for connected nodes we always require that the node has the required feature.

Type Parameters:

T - the type of the custom

Parameters:

out - the output stream

custom - the custom to serialize

Returns:

true if the custom should be serialized and false otherwise