Make a simple graph OR add a unique edge between two vertex

[Vitor Mangaravite]

Hello,

I'm trying make a simple graph, so, make a graph without more than a edge between two vertex. Using gremlin, don't have a query to identify if, considering two vertex, exists any edge between them. To solve this, I implement a simple function to find, by the first vertex, if exists one edge to the second. But, my implemention is too slow. I think that happens because I don't have any properties of both vertex, so, using just titan vertex id. This is my implementation:

boolean has = false;

GremlinPipeline pipe = new GremlinPipeline();
pipe.start(vertex1);

for(Object t1 : pipe.out()){

   Vertex v1t = (Vertex) t1;

   if(v1t.getId().equals(vertex2.getId()))

       has = true;

}

What can I do?

I'm using thinkaurelius.titan 0.5.4 (core, cassandra and elasticsearch).

Thank you!

[Jason Plurad]

Try defining an edge label with Multiplicity.ONE2ONE http://s3.thinkaurelius.com/docs/titan/0.5.4/schema.html#_edge_label_multiplicity

gremlin> conf = new BaseConfiguration()

==>org.apache.commons.configuration.BaseConfiguration@e903e28

gremlin> conf.setProperty('storage.backend', 'inmemory')

==>null

gremlin> g = TitanFactory.open(conf)

==>titangraph[inmemory:[127.0.0.1]]

gremlin> mgmt = g.getManagementSystem()

==>com.thinkaurelius.titan.graphdb.database.management.ManagementSystem@72ca7fc

gremlin> friend = mgmt.makeEdgeLabel('friend').multiplicity(Multiplicity.ONE2ONE).make()

==>friend

gremlin> mgmt.commit()

==>null

gremlin> v0 = g.addVertex()

==>v[256]

gremlin> v1 = g.addVertex()

==>v[512]

gremlin> v0.addEdge('friend', v1)

==>e[dc-74-1lh-e8][256-friend->512]

gremlin> v0.addEdge('friend', v1)

An edge with the given label already exists on the out-vertex and the label [friend] is out-unique

Display stack trace? [yN]