public interface IGraphAccessor
Modifier and Type  Method and Description 

void 
advanceView()
Hook to advance the view of the graph.

VertexDistribution 
getDistribution(Random r)
Obtain a weighted distribution of the vertices in the graph from which
samples may then be taken.

long 
getEdgeCount(IGASContext<?,?,?> ctx,
org.openrdf.model.Value u,
EdgesEnum edges)
Return the #of edges of the specified type for the given vertex.

Iterator<org.openrdf.model.Statement> 
getEdges(IGASContext<?,?,?> ctx,
org.openrdf.model.Value u,
EdgesEnum edges)
Return the edges for the given vertex.

long getEdgeCount(IGASContext<?,?,?> ctx, org.openrdf.model.Value u, EdgesEnum edges)
Note: This is not always a flyweight operation due to the need to filter
for only the observable edge types. If this information is required, it
may be best to cache it on the vertex state object for a given
IGASProgram
.
ctx
 The IGASContext
.u
 The vertex.edges
 Typesafe enumeration indicating which edges should be visited.Iterator<org.openrdf.model.Statement> getEdges(IGASContext<?,?,?> ctx, org.openrdf.model.Value u, EdgesEnum edges)
ctx
 The IGASContext
.u
 The vertex.edges
 Typesafe enumeration indicating which edges should be visited.void advanceView()
IGASProgram
.VertexDistribution getDistribution(Random r)
r
 A random number generator that (a) MAY be used to select the
sample distribution (the distribution does not need to be
exhaustive so long as it obeys the sampling requirements); and
(b) WILL be used to select vertices from that distribution.This COULD be fixed if we required the implementation to put the sampled vertices into an order based on their external representation as RDF Values, but still reporting their internal since that is what is used to actually specify a starting vertex of the GAS program. However, even then, implementation specific characteristics might not provide us with the same vertices (e.g., bigdata imposes a canonical mapping on xsd:dateTime).
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