static object[] GetArguments(JsonRpcRequest request, MethodInfo methodInfo)
{
var methodParams = methodInfo.GetParameters();
var args = new object[methodParams.Length];
for (var i = 0; i < methodParams.Length; i++)
{
if (i >= request.Params.Length) continue;
var jsonArg = request.Params[i];
args[i] = jsonArg;
}
return args;
}
public JsonRpcResponse Invoke(object service, JsonRpcRequest request)
{
var serviceType = service.GetType();
var methods = serviceType.GetMethods().Where(m => string.Equals(m.Name, request.Method, StringComparison.OrdinalIgnoreCase)).ToList();
if (methods.Count == 0)
{
throw new MissingMethodException(serviceType.FullName, request.Method);
}
var method = SelectMethod(methods, request);
var args = GetArguments(request, method);
var result = method.Invoke(service, args);
return new JsonRpcResponse {Id = request.Id, Result = result};
}
static JsonRpcResponse CreateError(Exception ex, JsonRpcRequest request)
{
Log.Error(ex.Message);
Log.Error(ex.ToString());
return new JsonRpcResponse
{
Id = request == null ? null : request.Id,
Error = new JsonRpcError {Code = ex.GetType().Name, Message = ex.Message, Data = ex.ToString()}
};
}
static MethodInfo SelectMethod(IList<MethodInfo> methods, JsonRpcRequest request)
{
var argumentTypes = request.Params.Select(s => s == null ? null : s.GetType()).ToList();
var matches = new List<MethodInfo>();
foreach (var method in methods)
{
var parameters = method.GetParameters();
if (parameters.Length != argumentTypes.Count)
{
continue;
}
var isMatch = true;
for (var i = 0; i < parameters.Length; i++)
{
var paramType = parameters[i].ParameterType;
var argType = argumentTypes[i];
if (argType == null && paramType.IsValueType)
{
isMatch = false;
break;
}
if (argType != null && !paramType.IsAssignableFrom(argType))
{
isMatch = false;
break;
}
}
if (isMatch)
{
matches.Add(method);
}
}
if (matches.Count == 1)
return matches[0];
var message = new StringBuilder();
if (matches.Count > 1)
{
message.AppendLine("More than one possible match for the requested service method was found given the argument types. The matches were:");
foreach (var match in matches)
{
message.AppendLine(" - " + match);
}
}
else
{
message.AppendLine("Could not decide which candidate to call out of the following methods:");
foreach (var match in methods)
{
message.AppendLine(" - " + match);
}
}
message.AppendLine("The request arguments were:");
message.AppendLine(string.Join(", ", argumentTypes.Select(t => t == null ? "<null>" : t.Name)));
throw new AmbiguousMatchException(message.ToString());
}
JsonRpcRequest CreateRequest(IMethodMessage methodCall)
{
var activityId = Guid.NewGuid();
var method = ((MethodInfo) methodCall.MethodBase);
var request = new JsonRpcRequest
{
Id = contractType.Name + "::" + method.Name + "[" + Interlocked.Increment(ref callId) + "] / " + activityId,
ActivityId = activityId,
Service = contractType.Name,
Method = method.Name,
Params = methodCall.Args
};
return request;
}
JsonRpcResponse DispatchRequest(JsonRpcRequest request)
{
return rpcClient.Post(endPoint, request);
}