RPC Server: Advanced Usages

If you have read RPC Server: Getting Started, here you can learn some more advanced usages on server-side RPC handling.

Middlewares

Like "middlewares" in ASP.NET Core, in JsonRpc.Standard, it's possible to intercept the incoming JSON-RPC Request messages and customize the way they are processed. In JsonRpc.Standard, the middlewares are added by calling JsonRpcServiceHostBuilder.Intercept. For example, if you want to log the timing of each requests and responses, you may insert a middleware before the actual method dispatching and invocation step. Here is how it's done in UnitTestProject1.Utility

public static IJsonRpcServiceHost CreateJsonRpcServiceHost(UnitTestBase owner)
{
    var builder = new JsonRpcServiceHostBuilder();
    builder.Register(typeof(Utility).GetTypeInfo().Assembly);
    builder.ContractResolver = DefaultContractResolver;
    var globalSw = Stopwatch.StartNew();
    var session = new SessionFeature();
    if (owner.Output != null)
    {
        builder.Intercept(async (context, next) =>
        {
            var sw = Stopwatch.StartNew();
            owner.Output.WriteLine("{0}> {1}", globalSw.Elapsed, context.Request);
            try
            {
                context.Features.Set(session);
                await next();
                owner.Output.WriteLine("{0}< {1}", globalSw.Elapsed, context.Response);
            }
            finally
            {
                owner.Output.WriteLine("Server: Ellapsed time: {0}", sw.Elapsed);
            }
        });
    }
    builder.LoggerFactory = owner.LoggerFactory;
    return builder.Build();
}

in this xUnit-based unit test project, I used ITestOutputHelper provided by xUnit to print the timings, which will give me the following output

00:00:00.3802118> {"id":"32106157#1","method":"one","jsonrpc":"2.0"}
00:00:00.8513458< {"id":"32106157#1","result":1,"jsonrpc":"2.0"}
Server: Ellapsed time: 00:00:00.4970798
00:00:00.9267219> {"id":"32106157#2","method":"one","params":{"negative":false},"jsonrpc":"2.0"}
00:00:00.9487014< {"id":"32106157#2","result":1,"jsonrpc":"2.0"}
Server: Ellapsed time: 00:00:00.0223802
00:00:00.9496177> {"id":"32106157#3","method":"one","params":{"negative":true},"jsonrpc":"2.0"}
00:00:00.9500884< {"id":"32106157#3","result":-1,"jsonrpc":"2.0"}
Server: Ellapsed time: 00:00:00.0020213
00:00:00.9521625> {"id":"32106157#4","method":"two","jsonrpc":"2.0"}
00:00:00.9572604< {"id":"32106157#4","result":2,"jsonrpc":"2.0"}
Server: Ellapsed time: 00:00:00.0055367
00:00:00.9582994> {"id":"32106157#5","method":"two","params":{"negative":false},"jsonrpc":"2.0"}
00:00:00.9586298< {"id":"32106157#5","result":2,"jsonrpc":"2.0"}
Server: Ellapsed time: 00:00:00.0005468
00:00:00.9590794> {"id":"32106157#6","method":"two","params":{"negative":true},"jsonrpc":"2.0"}
00:00:00.9593365< {"id":"32106157#6","result":-2,"jsonrpc":"2.0"}
Server: Ellapsed time: 00:00:00.0004628

Features