Orleans Graph

Declare the grain-to-grain traffic you allow, block everything else, and see the graph in real time.

What You Get

• Fluent builder and attributes for defining permitted grain hops
• Incoming/outgoing filters that stop unauthorised calls before your code runs
• Deadlock detection with opt-in reentrancy
• Mermaid diagrams for both configured policy and live call history

Quick Start

// Silo
builder.AddOrleansGraph(
    configureGraph: graph =>
    {
        graph.AddGrainTransition<IOrderGrain, IPaymentGrain>()
             .Method(o => o.SubmitAsync(default!), p => p.ChargeAsync(default!))
             .WithReentrancy()
             .And()
             .AllowClientCallGrain<IOrderGrain>();
    });

// Client – attributes + defaults are enough
clientBuilder.AddOrleansGraph();

[AllowClientCall]
[AllowGrainCall(typeof(IPaymentGrain), AllowAllMethods = true, AllowReentrancy = true)]
public interface IOrderGrain : IGrainWithStringKey
{
    Task SubmitAsync(Order dto);
}

[AllowSelfReentrancy]
[AllowGrainCall(typeof(IOrderGrain), SourceMethods = new[] { nameof(IPaymentGrain.ChargeAsync) }, TargetMethods = new[] { nameof(IOrderGrain.SubmitAsync) })]
public interface IPaymentGrain : IGrainWithStringKey
{
    Task ChargeAsync(Payment payment);
}

public record Payment;

Visualise the Graph (Mermaid)

var manager = services.GetRequiredService<GrainTransitionManager>();
var policy = manager.GeneratePolicyMermaidDiagram();

var history = new CallHistory();
history.Push(new OutCall(null, null, typeof(IOrderGrain).FullName!, typeof(IPaymentGrain).FullName!, "SubmitAsync"));
history.Push(new InCall(null, null, typeof(IPaymentGrain).FullName!, "ChargeAsync"));
var live = manager.GenerateLiveMermaidDiagram(history);

--> means allowed, -.-> reentrant, ==> active edge with hits: N.

Runtime Guarantees

• Outgoing filter records every hop; incoming filter enforces the graph
• Deadlocks are detected unless the edge is marked reentrant
• Client → grain rules reuse the same builder/attribute API

Tests & Coverage

dotnet format Orleans.Graph.slnx
dotnet test Orleans.Graph.slnx --configuration Release -p:CollectCoverage=true -p:CoverletOutput=coverage/

Automated suites cover fluent policies, attribute discovery (AppDomain scan), attribute-only TestCluster, and graph internals (~86 % line / 81 % branch).

License

MIT – see LICENSE.