internal async Task ReadVertexStateAsync(GrainReference grainReference, VertexState vertexState)
{
var readExpression = $"g.V('{grainReference.ToKeyString()}')";
var graphElementGrain = grainReference.AsReference <IGraphElementGrain>();
var feedOptions = new FeedOptions
{
MaxItemCount = 1,
PartitionKey = new PartitionKey(graphElementGrain.GetGraphPartition())
};
var readQuery = client.CreateGremlinQuery <CosmosDbVertex>(graph, readExpression, feedOptions, GraphSONMode.Normal);
var response = await readQuery.ExecuteNextAsync <CosmosDbVertex>();
log.Info($"CosmosDB: Read Vertex State: Request Charge: {response.RequestCharge}");
var vertex = response.FirstOrDefault();
if (vertex == null)
{
return;
}
vertexState.Persisted = true;
foreach (var edge in vertex.GetInEdges())
{
var edgeReference = grainReferenceConverter.GetGrainFromKeyString(edge.Id.ToString());
edgeReference.BindGrainReference(grainFactory);
var vertexReference = grainReferenceConverter.GetGrainFromKeyString(edge.InVertexId.ToString());
vertexReference.BindGrainReference(grainFactory);
vertexState.AddInEdge(edgeReference.AsReference <IEdge>(), vertexReference.AsReference <IVertex>());
}
foreach (var edge in vertex.GetOutEdges())
{
var edgeReference = grainReferenceConverter.GetGrainFromKeyString(edge.Id.ToString());
edgeReference.BindGrainReference(grainFactory);
var vertexReference = grainReferenceConverter.GetGrainFromKeyString(edge.InVertexId.ToString());
vertexReference.BindGrainReference(grainFactory);
vertexState.AddOutEdge(edgeReference.AsReference <IEdge>(), vertexReference.AsReference <IVertex>());
}
foreach (var property in vertex.GetVertexProperties())
{
if (property.Key[0] == '@' || property.Key == "partition")
{
continue;
}
var vertexProperty = vertexState.SetProperty(property.Key, property.Value.ToString());
try
{
foreach (var subProperty in property.GetProperties())
{
if (subProperty.Key[0] == '@')
{
continue;
}
vertexProperty.SetMeta(subProperty.Key, subProperty.Value.ToString());
}
}
// BUG: The Microsoft.Azure.Graphs library throws an exception when enumerating over empty properties. How do we check or work around this?
catch (NullReferenceException) { }
}
}
