registry.relay

Relays an RPC call to a specific device through the registry server. This is used when two devices have not yet established a direct connection.

Request

Field	Value
Method	registry.relay
Return Method	(empty string)
Arguments	2

Arguments

#	Type	Description
1	BMRegistryInfo	The target device to relay the message to.
2	BMInvoke	The RPC call to forward to the target device.

The return method is an empty string because relay messages are fire-and-forget from the sender's perspective. The response, if any, comes from the target device via a separate relay or direct connection.

Primary Use Case: deviceConnectRequested

The main use of registry.relay is to initiate a direct connection between a controller and a game host:

1. The controller selects a game host from the list received via onList.
2. The controller calls registry.relay with:
   • Target: The selected host's BMRegistryInfo.
   • Payload: A BMInvoke calling deviceConnectRequested with the controller's own BMRegistryInfo as the argument.
3. The registry server forwards this BMInvoke to the game host.
4. The game host receives the deviceConnectRequested call, opens a direct TCP connection to the controller using the address from the relayed BMRegistryInfo, and sends an AckPacket over the new direct connection.

sequenceDiagram
    participant Controller
    participant Server as Registry Server
    participant Host as Game Host

    Controller->>Server: registry.relay(HostInfo, deviceConnectRequested)
    Server->>Host: deviceConnectRequested(ControllerInfo)

    note over Host,Controller: Direct Connection Initiated
    Host->>Controller: TCP Connect to Controller IP
    Host->>Controller: Handshake
    Host->>Controller: AckPacket (Channel 0)

Notes

• The relay payload is a nested BMInvoke inside the outer registry.relay invoke. See BMInvoke for the wire format.
• The registry server does not interpret the relayed BMInvoke; it simply forwards it to the target device.