/// <summary>
/// Handles invokations on the proxy.
/// </summary>
/// <param name="targetMethod">The target method.</param>
/// <param name="args">The arguments.</param>
/// <returns></returns>
protected override object Invoke(MethodInfo targetMethod, object[] args)
{
// get operation attribute
RpcOperationAttribute attr = targetMethod.GetCustomAttribute <RpcOperationAttribute>();
if (attr == null)
{
throw new InvalidOperationException("The interface member must be decorated with an operation attribute");
}
// check encryption requirement
if ((_contractAttr.RequireEncryption || attr.RequireEncryption) && !_channel.IsEncrypted)
{
throw new SecurityException("The contract or operation requires an encrypted channel");
}
// generate generic method
Type genericType = typeof(bool);
Type memberType = targetMethod.ReturnType;
TypeInfo memberTypeInfo = memberType.GetTypeInfo();
//TODO: add support for sync methods
if (memberType != typeof(Task) && memberTypeInfo.BaseType != typeof(Task))
{
throw new InvalidOperationException("The interface member must return an awaitable task");
}
if (memberTypeInfo.IsGenericType)
{
if (attr.NoReply)
{
throw new InvalidOperationException("The method result cannot be retrieved with no reply on");
}
genericType = memberTypeInfo.GetGenericArguments()[0];
}
// invoke
return(_invokeMethodInfo.MakeGenericMethod(genericType).Invoke(this, new object[] { targetMethod, args, targetMethod.ReturnType }));
}
/// <summary>
/// Takes the parsed header and envelope and applies correct type handler.
/// </summary>
/// <param name="header">The header.</param>
/// <param name="envelope">The envelope.</param>
/// <returns></returns>
private async Task ApplyAsync(RpcHeader header, Envelope envelope)
{
if (header.Type == RpcMessageType.Single)
{
// find serializer for this request
RpcRequest req = null;
IRpcSerializer serializer = null;
if (!RpcSerializer.Serializers.TryGetValue(header.Serializer, out serializer))
{
throw new NotSupportedException("The serializer is not supported by RPC");
}
// deserialize into a request
RpcResponse res = null;
try {
req = serializer.DeserializeRequest(envelope.Body, (i, o) => RpcArgument.FromMember(GetMember(i, o)));
} catch (KeyNotFoundException) {
res = new RpcResponse("InterfaceNotFound", "The interface or operation could not be found", null);
} catch (Exception ex) {
res = new RpcResponse("ArgumentInvalid", string.Format("The request format is invalid: {0}", ex.Message), null);
}
// apply single request
MemberInfo memberInfo = null;
try {
if (req != null)
{
memberInfo = GetMember(req.Interface, req.Operation);
}
} catch (KeyNotFoundException) {
res = new RpcResponse("OperationNotFound", "The interface or operation could not be found", null);
}
// get operation information
RpcOperationAttribute opAttr = null;
if (memberInfo != null)
{
Type interfaceType = GetInterface(req.Interface);
MemberInfo[] interfaceMember = interfaceType.GetMember(req.Operation);
opAttr = interfaceMember[0].GetCustomAttribute <RpcOperationAttribute>();
}
// get if no reply is enabled
bool noReply = opAttr != null && opAttr.NoReply;
// check if they have a response ID if no reply isn't enabled
if (!noReply && envelope.ID == Guid.Empty)
{
res = new RpcResponse("InvalidOperation", "The envelope does not specify a correlation ID", null);
}
// apply request if we don't have a response already, typically an error
if (res == null)
{
// setup context
RpcContext.Current = new RpcContext()
{
Envelope = envelope
};
// apply request
res = await ApplyRequestAsync(req, memberInfo).ConfigureAwait(false);
// destroy context
RpcContext.Current = null;
}
// send response unless no-reply
if (!noReply)
{
// serialize response
byte[] resBody = serializer.SerializeResponse(res);
// send reply
string rpcHeader = new RpcHeader(RpcHeader.HEADER_VERSION, serializer.Name, RpcMessageType.Single).ToString();
Dictionary <string, object> headers = new Dictionary <string, object>(StringComparer.CurrentCultureIgnoreCase)
{
{ RpcHeader.HEADER_NAME, rpcHeader },
{ RpcHeader.HEADER_NAME_LEGACY, rpcHeader }
};
// reply
await envelope.ReplyAsync(resBody, headers).ConfigureAwait(false);
}
// throw exceptions
}
else
{
throw new NotImplementedException("Batched RPC is not supported currently");
}
}
