Package org.apache.flink.streaming.api.graph

Class StreamGraphUserHashHasher

java.lang.Object

org.apache.flink.streaming.api.graph.StreamGraphUserHashHasher

All Implemented Interfaces:

StreamGraphHasher

public class StreamGraphUserHashHasher
extends Object
implements StreamGraphHasher

StreamGraphHasher that works with user provided hashes. This is useful in case we want to set (alternative) hashes explicitly, e.g. to provide a way of manual backwards compatibility between versions when the mechanism of generating hashes has changed in an incompatible way.

Constructor Summary

Constructors

Constructor	Description
StreamGraphUserHashHasher()

Method Summary

Modifier and Type	Method	Description
boolean	generateHashesByStreamNodeId(int streamNodeId, StreamGraph streamGraph, Map<Integer,byte[]> hashes)	Generates a hash for StreamNode with the specified stream node id in the StreamGraph.
Map<Integer,byte[]>	traverseStreamGraphAndGenerateHashes(StreamGraph streamGraph)	Returns a map with a hash for each StreamNode of the StreamGraph.

Methods inherited from class java.lang.Object

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

Constructor Detail

StreamGraphUserHashHasher

public StreamGraphUserHashHasher()

Method Detail

traverseStreamGraphAndGenerateHashes

public Map<Integer,byte[]> traverseStreamGraphAndGenerateHashes(StreamGraph streamGraph)

Description copied from interface: StreamGraphHasher

Returns a map with a hash for each StreamNode of the StreamGraph. The hash is used as the JobVertexID in order to identify nodes across job submissions if they didn't change.

Specified by:

traverseStreamGraphAndGenerateHashes in interface StreamGraphHasher

generateHashesByStreamNodeId

public boolean generateHashesByStreamNodeId(int streamNodeId,
                                            StreamGraph streamGraph,
                                            Map<Integer,byte[]> hashes)

Description copied from interface: StreamGraphHasher

Generates a hash for StreamNode with the specified stream node id in the StreamGraph. This hash is stored in the provided map and can be used to uniquely identify the StreamNode across job submissions, assuming its configuration remains unchanged.

Specified by:

generateHashesByStreamNodeId in interface StreamGraphHasher