veloren/server/src/sys/msg/ping.rs

use super::super::SysTimer;
use crate::{
    client::Client,
    metrics::PlayerMetrics,
    streams::{GetStream, PingStream},
    Settings,
};
use common::{
    event::{EventBus, ServerEvent},
    msg::PingMsg,
    span,
    state::Time,
};
use specs::{Entities, Join, Read, ReadExpect, System, Write, WriteStorage};
use tracing::{debug, info};

impl Sys {
    fn handle_ping_msg(
        ping_stream: &mut PingStream,
        msg: PingMsg,
    ) -> Result<(), crate::error::Error> {
        match msg {
            PingMsg::Ping => ping_stream.send(PingMsg::Pong)?,
            PingMsg::Pong => {},
        }
        Ok(())
    }
}

/// This system will handle new messages from clients
pub struct Sys;
impl<'a> System<'a> for Sys {
    #[allow(clippy::type_complexity)] // TODO: Pending review in #587
    type SystemData = (
        Entities<'a>,
        Read<'a, EventBus<ServerEvent>>,
        Read<'a, Time>,
        ReadExpect<'a, PlayerMetrics>,
        Write<'a, SysTimer<Self>>,
        WriteStorage<'a, Client>,
        WriteStorage<'a, PingStream>,
        Read<'a, Settings>,
    );

    #[allow(clippy::match_ref_pats)] // TODO: Pending review in #587
    #[allow(clippy::single_char_pattern)] // TODO: Pending review in #587
    #[allow(clippy::single_match)] // TODO: Pending review in #587
    fn run(
        &mut self,
        (
            entities,
            server_event_bus,
            time,
            player_metrics,
            mut timer,
            mut clients,
            mut ping_streams,
            settings,
        ): Self::SystemData,
    ) {
        span!(_guard, "run", "msg::ping::Sys::run");
        timer.start();

        let mut server_emitter = server_event_bus.emitter();

        for (entity, client, ping_stream) in (&entities, &mut clients, &mut ping_streams).join() {
            let res = super::try_recv_all(ping_stream, |ping_stream, msg| {
                Self::handle_ping_msg(ping_stream, msg)
            });

            match res {
                Err(e) => {
                    debug!(?entity, ?e, "network error with client, disconnecting");
                    player_metrics
                        .clients_disconnected
                        .with_label_values(&["network_error"])
                        .inc();
                    server_emitter.emit(ServerEvent::ClientDisconnect(entity));
                },
                Ok(1_u64..=u64::MAX) => {
                    // Update client ping.
                    client.last_ping = time.0
                },
                Ok(0) => {
                    if time.0 - client.last_ping > settings.client_timeout.as_secs() as f64
                    // Timeout
                    {
                        info!(?entity, "timeout error with client, disconnecting");
                        player_metrics
                            .clients_disconnected
                            .with_label_values(&["timeout"])
                            .inc();
                        server_emitter.emit(ServerEvent::ClientDisconnect(entity));
                    } else if time.0 - client.last_ping
                        > settings.client_timeout.as_secs() as f64 * 0.5
                    {
                        // Try pinging the client if the timeout is nearing.
                        ping_stream.send_unchecked(PingMsg::Ping);
                    }
                },
            }
        }

        timer.end()
    }
}