The interface struct has the type,version and methods of the
interface.
Make spa interfaces extend from spa_interface and make a
separate structure for the methods.
Pass a generic void* as the first argument of methods, like
we don in PipeWire.
Bundle the methods + implementation in a versioned inteface
and use that to invoke methods. This way we can do version
checks on the methods.
Make resource and proxy interfaces that we can can call. We
can then make the core interfaces independent on proxy/resource and
hide them in the lower layers.
Add add_listener method to methods of core interfaces, just
like SPA.
Don't pass the ucred to the client construct, just set the properties
in the protocol.
Use the client properties to get ucred.
Add the security label to the client properties (from SO_PEERSEC)
Pass a message around to make things more extensible later.
Keep fds per message if we ever want to write individual
messages.
Pass number of fds in the message header. We might need this to
close the fds when the proxy is gone.
Add a node subscribe params method that automatically emits the new
params when they change so that we can avoid an enum_params.
Use this in the stream object.
Remove the control messages to update controls in stream, use the
set_param. This is more overhead but allows for notifications to other
clients.
Make it possible to update many controls in one go.
Make a get node method that binds to the server side node of the
client-node immediately. use this in the remote_export and always
return a node proxy.
Use the node proxy to get property updates and signal those in the
stream.
Output controls can be linked to many input controls and many input
controls can receive input from many output controls. Keep the control
link information inside the link.
Just prepare the output on the port and signal ready. When the graph
completes we will be signaled again to recycle the buffer and
prepare more output if we can.
Improve the bookkeeping a little when activating nodes.
Fix race with moving nodes between drivers.
When we have a client driver node, it will have prepared the io
areas for us before sending the ready signal. We then need to run
the converters before signaling ready.
Simplify the scheduling by using simple lists and removing the
subgraphs etc..
Make the driver node trigger all nodes it manages and when they
complete, trigger the driver node to finish the graph.
Remove the mix states, we can get rid of them when:
The format is the same for all mixer ports. Set the existing
format on new mixer ports. When the first format is set, the port
becomes READY. When all mixer ports are cleared the port goes back
to CONFIGURE.
Only output ports allocate and manage buffers, input ports share
the buffers of the peer output port on the link.
