how to set the kC4ReplicatorHeartbeatInterval in C4ReplicatorParams

[CedricCouton]

Hi,

I would like to set the heartbeat params to the c4replicatorparams (kC4ReplicatorHeartbeatInterval) how can do it this library ? Perhaps we can have a new_with_options in Replicator ?

Thanks

[Dushistov]

I suppose it can be set_option(&mut self, ...). But you should take into consideration
that if you used tokio based network transport that option would be ignored.
It is not implemented yet.

[CedricCouton]

This option is used by the c4WebSocket no ? In WebSocketImpl.cc lig 116 if (heartbeatInterval() > 0) { _pingTimer.reset(new actor::Timer(bind(&WebSocketImpl::sendPing, this))); schedulePing(); }
So it is independent to tokio (i think), the schedulePing sendBytes throw the factory write function I think. What's your opinion ?

[CedricCouton]

You are right, the params is only used in the c4 wbesocket impl...
I have to search in tokio side. But in tungstenite the TcpStream is not exposed so it's not possible to call the set_keepalive.

[Dushistov]

couchbase-lite (C/C++) part has two alternatives to work with web sockets:

1. work with raw bytes stream (so couchbase-lite parse data by itself)
2. work with messages handled by C4SocketFactory

Because of usage of API of tungstenite this crate uses variant (2).

So to handle it in the write way, some extra functional should be added here:

couchbase-lite-rust/couchbase-lite/src/repl_transport.rs

Line 425 in 6b2820d

debug!("read loop({:x}): ping", sock_id);

to handle ping/pong messages and
plus it should some kind of finite state machine based on tokio timers to handle missed pong message and inform C/C++ part of this library about problem.

I have plans to implement this, but I was busy.