You got 1 correct. Everything that happens gets sent immediately as an event to the server (e.g. KeyDownEvent). These are pushed without blocking for a response to each - The websocket guarantees delivery and ordering.
Upon receiving an event from the client socket, it is immediately inserted into the LMAX ring buffer for processing.
Updates to the client are triggered by events+state determining when a redraw is required and issuing a special "ClientRedraw" event into the same queue. These events are grouped by client so that we can aggregate multiple potential updates in a single actual redraw. These result in view updates being pushed back down to the relevant clients. One performance trick here is that the client redraw is dispatched asynchronously from the server, so there is no blocking on processing the subsequent batches each time.
You can think of an E2E client view update as always requiring 2 events - the client event that triggered the change to domain state, and the actual redraw event(s) that result. For applications where the client should update at a fixed interval (e.g. game), a high performance timer implementation injects periodic redraw events. Because the upper bound of the ring buffer latency is around a millisecond, this allows for incredibly low jitter on real time events. Scheduling client draws as simple domain events is feasible.
Upon receiving an event from the client socket, it is immediately inserted into the LMAX ring buffer for processing.
Updates to the client are triggered by events+state determining when a redraw is required and issuing a special "ClientRedraw" event into the same queue. These events are grouped by client so that we can aggregate multiple potential updates in a single actual redraw. These result in view updates being pushed back down to the relevant clients. One performance trick here is that the client redraw is dispatched asynchronously from the server, so there is no blocking on processing the subsequent batches each time.
You can think of an E2E client view update as always requiring 2 events - the client event that triggered the change to domain state, and the actual redraw event(s) that result. For applications where the client should update at a fixed interval (e.g. game), a high performance timer implementation injects periodic redraw events. Because the upper bound of the ring buffer latency is around a millisecond, this allows for incredibly low jitter on real time events. Scheduling client draws as simple domain events is feasible.