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JanusGraph.Net

JanusGraph.Net extends Apache TinkerPop™'s Gremlin.Net with support for JanusGraph-specific types.

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Usage

To connect to JanusGraph Server, a GremlinClient instance needs to be created and configured with a message serializer that adds support for JanusGraph specific types.

This can be done like this for GraphSON 3:

var client = new GremlinClient(new GremlinServer("localhost", 8182),
    new JanusGraphGraphSONMessageSerializer());

or like this for GraphBinary (see Serialization Formats for more information about GraphSON 3 and GraphBinary):

var client = new GremlinClient(new GremlinServer("localhost", 8182),
    new GraphBinaryMessageSerializer(JanusGraphTypeSerializerRegistry.Instance));

Note that the client should be disposed on shut down to release resources and to close open connections with client.Dispose(). The client can then be used to configure a GraphTraversalSource:

// Add this static using to be able to call `Traversal()` "anonymously"
using static Gremlin.Net.Process.Traversal.AnonymousTraversalSource;

var g = Traversal().WithRemote(new DriverRemoteConnection(client));
// Reuse 'g' across the application

The GraphTraversalSource g can now be used to spawn Gremlin traversals:

var herculesAge = g.V().Has("demigod", "name", "hercules").Values<int>("age")
    .Next();
Console.WriteLine($"Hercules is {herculesAge} years old.");

The traversal can also be executed asynchronously by using Promise() which is recommended as the underlying driver in Gremlin.Net also works asynchronously:

var herculesAge = await g.V().Has("demigod", "name", "hercules")
    .Values<int>("age")
    .Promise(t => t.Next());

Refer to the chapter Gremlin Query Language in the JanusGraph docs for an introduction to Gremlin and pointers to further resources. The main syntactical difference for Gremlin.Net is that it follows .NET naming conventions, e.g., method names use PascalCase instead of camelCase.

Text Predicates

The Text class provides methods for full-text and string searches:

await g.V().Has("demigod", "name", Text.TextPrefix("herc"))
    .Promise(t => t.ToList());

The other text predicates can be used the same way.

Geoshapes

The Geoshape class in the JanusGraph.Net.Geoshapes namespace can be used to construct Geoshapes:

await g.V().Has("demigod", "name", "hercules").OutE("battled")
    .Has("place", Geoshape.Point(38.1f, 23.7f)).Count().Promise(t => t.Next());

Only the Point Geoshape is supported right now.

Version Compatibility

The lowest supported JanusGraph version is 0.3.0. The following table shows the supported JanusGraph versions for each version of JanusGraph.Net:

JanusGraph.Net JanusGraph
0.1.z 0.3.z
0.2.z 0.4.z, 0.5.z
0.3.z 0.4.z, 0.5.z, 0.6.z
0.4.z (0.4.z, 0.5.z,) 0.6.z
1.0.z (0.6.z,) 1.0.z

While it should also be possible to use JanusGraph.Net with other versions of JanusGraph than mentioned here, compatibility is not tested and some functionality (like added Gremlin steps) will not work as it is not supported yet in case of an older JanusGraph version or was removed in a newer JanusGraph version.

JanusGraph.Net 0.4

JanusGraph.Net 0.4 still supports older versions of JanusGraph, but the janusGraphPredicates flag needs to be set to false in order to be able to use JanusGraph's Text predicates.

JanusGraph.Net 1.0

GraphBinary serialization includes breaking changes in version 1.0.0. JanusGraph.Net 1.0 is therefore only compatible with JanusGraph 0.6 if GraphSON is used.

Serialization Formats

JanusGraph.Net supports GraphSON 3 as well as GraphBinary. Note that support for GraphBinary was only added in JanusGraph 0.6.0. So, the server needs to be at least on that version.

Not all of the JanusGraph-specific types are already supported by both formats:

Format RelationIdentifier Text predicates Geoshapes Geo predicates
GraphSON3 x x Point -
GraphBinary x x Point* -

* Since version 1.0.0 of JanusGraph.Net. JanusGraph also needs to be on version 1.0.0 or higher.

Community

JanusGraph.Net uses the same communication channels as JanusGraph in general. So, please refer to the Community section in JanusGraph's main repository for more information about these various channels.

Please use GitHub issues only to report bugs or request features.

Contributing

Please see CONTRIBUTING.md in JanusGraph's main repository for more information, including CLAs and best practices for working with GitHub.

License

JanusGraph.Net code is provided under the Apache 2.0 license and documentation is provided under the CC-BY-4.0 license. For details about this dual-license structure, please see LICENSE.txt.