IPC event messages are too large

[Alexandros Frantzis]

For many events we send to the client (mir_event_type_surface, mir_event_type_resize etc) we pack the whole raw MirEvent structure, resulting in messages of size > 1KiB, from which only a few bytes are needed.

[Daniel van Vugt (vanvugt)]

Yeah, this has been a theoretical issue for a while. Although having experimented with shrinking event structures I have not yet found anywhere that this is a noticeable performance issue. So we should improve it, but I'm not sure any improvement will provide measurable benefit.

[Daniel van Vugt (vanvugt)]

It's important to remember that the really large events (motion events) are not sent using the MirEvent structure. Input is sent in the raw event structure from Android, and then converted to MirEvent in the client. So this bug is indeed just about surface events (resize, attributes).

[Michał Sawicz (saviq)]

Syncing task from Mir.