private async Task DispatchRpcMethod(RequestContext context)
{
if (!ValidateRequest(context))
{
return;
}
JsonRpcMethod method;
try
{
if (Contract.Methods.TryGetValue(context.Request.Method, out var candidates))
{
method = MethodBinder.TryBindToMethod(candidates, context);
}
else
{
TrySetErrorResponse(context, JsonRpcErrorCode.MethodNotFound,
$"Method \"{context.Request.Method}\" is not found.");
return;
}
}
catch (AmbiguousMatchException)
{
TrySetErrorResponse(context, JsonRpcErrorCode.InvalidParams,
$"Invocation of method \"{context.Request.Method}\" is ambiguous.");
return;
}
if (method == null)
{
TrySetErrorResponse(context, JsonRpcErrorCode.InvalidParams,
$"Cannot find method \"{context.Request.Method}\" with matching signature.");
return;
}
// Parse the arguments
object[] args;
try
{
args = MethodBinder.BindParameters(method.Parameters, context);
}
catch (Exception ex)
{
TrySetErrorResponse(context, JsonRpcErrorCode.InvalidParams, ex.Message);
if (context.Response != null)
{
context.Response.Error = ResponseError.FromException(ex, true);
}
return;
}
// Call the method
try
{
var result = await method.Invoker.InvokeAsync(context, args).ConfigureAwait(false);
// Produce the response.
if (context.Response != null && context.Response.Result == null && context.Response.Error == null)
{
if (result is ResponseError err)
{
context.Response.Error = err;
}
else
{
context.Response.Result = method.ReturnParameter.Converter.ValueToJson(result);
// JValue(null) is not `null`
Debug.Assert(context.Response.Result != null);
}
}
}
catch (JsonRpcException ex)
{
if (context.Response != null)
{
context.Response.Result = null;
context.Response.Error = ex.Error;
}
}
// Let other exceptions bubble up. We will handle them in the pipe, or finally in InvokePipeline.
}