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mirror of https://github.com/MaSzyna-EU07/maszyna.git synced 2026-10-17 21:29:19 +02:00
Files
maszyna/network/manager.cpp
Hirek193 30fa68cfd8 multiplayer stage 8: state correction and surviving a dropped connection
Two things were still missing once a session ran for a while: a peer that had
drifted apart from the authority had no way back short of restarting, and a
connection that blinked cost the player their seat and handed their vehicle to
the AI while the other driver was still sitting in it.

- a client that disagrees with the authoritative digest for 120 steps in a row
  asks to be put back in line, and the server answers with a fresh snapshot.
  There is a cooldown between requests, so a correction that needs a moment to
  take hold does not turn into a stream of them
- the server hands out a session token with its hello and remembers it. Present
  it again on the next connection and you come back as the same peer, with the
  same id
- a lost connection no longer removes the peer from its crews: the seat is held
  for a minute. Come back in time and nothing changed; stay away and the seat
  is given up properly, handing the vehicle back to the AI only when that
  leaves the crew empty and the AI was driving it in the first place
- after applying a snapshot a peer that finds itself on a crew walks into that
  cab, which is what makes a reconnect land the player back where they were
- the vehicle roster is sent to a joining peer right before its snapshot, so
  the crew section resolves to names instead of waiting for the next broadcast
2026-09-06 19:48:06 +00:00

199 lines
4.7 KiB
C++

/*
This Source Code Form is subject to the
terms of the Mozilla Public License, v.
2.0. If a copy of the MPL was not
distributed with this file, You can
obtain one at
http://mozilla.org/MPL/2.0/.
*/
#include "stdafx.h"
#include "network/manager.h"
#include "simulation/simulation.h"
#include "utilities/Logs.h"
#include "utilities/Globals.h"
#include "network/statehash.h"
network::server_manager::server_manager()
{
backbuffer = std::make_shared<std::fstream>("backbuffer.bin", std::ios::out | std::ios::in | std::ios::trunc | std::ios::binary);
}
command_queue::commands_map network::server_manager::pop_commands()
{
command_queue::commands_map map;
for (auto srv : servers)
add_to_dequemap(map, srv->pop_commands());
return map;
}
void network::server_manager::push_delta(double render_dt, double dt, uint64_t tick, uint64_t state_hash, const command_queue::commands_map &commands)
{
if (dt == 0.0 && commands.empty())
return;
frame_info msg;
msg.render_dt = render_dt;
msg.dt = dt;
msg.tick = tick;
msg.state_hash = state_hash;
msg.state_hash_version = STATE_HASH_VERSION;
msg.commands = commands;
for (auto srv : servers)
srv->push_delta(msg);
serialize_message(msg, *backbuffer.get());
}
void network::server_manager::create_server(const std::string &backend, const std::string &conf)
{
auto it = backend_list().find(backend);
if (it == backend_list().end()) {
ErrorLog("net: unknown backend: " + backend);
return;
}
servers.emplace_back(it->second->create_server(backbuffer, conf));
}
network::manager::manager()
{
}
void network::server_manager::publish_vehicle_list()
{
if (Entities.empty())
return;
Entities.refresh();
// resend on every change, and once in a while regardless, so that a peer which has
// just finished catching up does not have to wait for somebody to move
bool const changed = (Entities.entries() != last_published_list);
if (!changed && --publish_countdown > 0)
return;
last_published_list = Entities.entries();
publish_countdown = PUBLISH_INTERVAL_FRAMES;
vehicle_list msg;
msg.vehicles = last_published_list;
for (auto srv : servers)
srv->push_message(msg);
}
void network::server_manager::update_crews()
{
Crews.expire_absences();
Crews.reconcile();
if (--crew_publish_countdown <= 0) {
// peers that joined after somebody took a vehicle over have to learn about it too
crew_publish_countdown = PUBLISH_INTERVAL_FRAMES;
Crews.mark_all_pending();
}
auto const changed = Crews.take_pending_updates();
for (NetworkEntityId const id : changed) {
crew_update msg;
msg.entity_id = id;
msg.crew = Crews.crew_of(id);
for (auto srv : servers)
srv->push_message(msg);
}
}
void network::server_manager::apply_local_claim(NetworkEntityId entity_id)
{
auto const result = Crews.claim(PEER_HOST, entity_id);
if (result == claim_result::granted || result == claim_result::already_member) {
Global.network_lobby_message.clear();
Global.network_pending_vehicle = Entities.name_of(entity_id);
}
else {
WriteLog("net: refused local claim of vehicle " + std::to_string(entity_id) + ": " + describe(result), logtype::net);
Global.network_lobby_message = describe(result);
}
}
void network::server_manager::apply_local_leave(NetworkEntityId entity_id)
{
if (Crews.leave(PEER_HOST, entity_id))
Global.network_leave_pending = true;
}
void network::manager::request_claim(NetworkEntityId entity_id)
{
if (client) {
client->send_claim(entity_id);
return;
}
if (servers)
servers->apply_local_claim(entity_id);
}
void network::manager::request_leave(NetworkEntityId entity_id)
{
if (client) {
client->send_leave(entity_id);
// the server owns the roster, but stepping out of our own cab is a local matter
Global.network_leave_pending = true;
return;
}
if (servers)
servers->apply_local_leave(entity_id);
}
void network::manager::notify_scenario_loaded()
{
if (client)
client->send_ready();
}
void network::manager::request_resync(uint64_t tick, uint64_t state_hash)
{
if (client)
client->send_resync_request(tick, state_hash);
}
void network::manager::update()
{
for (auto &backend : backend_list())
backend.second->update();
if (servers && simulation::is_ready) {
servers->update_crews();
servers->publish_vehicle_list();
}
if (client)
client->update();
}
void network::manager::create_server(const std::string &backend, const std::string &conf)
{
servers.emplace();
servers->create_server(backend, conf);
}
void network::manager::connect(const std::string &backend, const std::string &conf)
{
auto it = backend_list().find(backend);
if (it == backend_list().end()) {
ErrorLog("net: unknown backend: " + backend);
return;
}
client = it->second->create_client(conf);
}
//std::unordered_map<std::string, std::shared_ptr<network::backend_manager>> network::backend_list;