stk-code_catmod/src/network/protocols/latency_protocol.cpp

141 lines
5.5 KiB
C++

#include "network/protocols/latency_protocol.hpp"
#include "network/event.hpp"
#include "network/network_config.hpp"
#include "network/stk_host.hpp"
#include "network/stk_peer.hpp"
#include "utils/time.hpp"
//-----------------------------------------------------------------------------
/** This protocol tries to determine the average latency between client and
* server. While this information is not used atm, it might be useful for
* the server to determine how much behind the clients it should start.
* FIXME: ATM the main thread will load the world as part of an update
* of the ProtocolManager (which updates the protocols). Since all protocols
* are locked dusing this update, the synchronisation protocol is actually
* delayed from starting while world is loading (since finding the protocol
* for a message requires the protocol lock) - causing at least two frames
* of significanlty delayed pings :(
*/
LatencyProtocol::LatencyProtocol()
: Protocol(PROTOCOL_SYNCHRONIZATION)
{
unsigned int size = STKHost::get()->getPeerCount();
m_pings.resize(size, std::map<uint32_t,double>());
m_successed_pings.resize(size, 0);
m_total_diff.resize(size, 0);
m_average_ping.resize(size, 0);
m_pings_count = 0;
} // LatencyProtocol
//-----------------------------------------------------------------------------
LatencyProtocol::~LatencyProtocol()
{
} // ~LatencyProtocol
//-----------------------------------------------------------------------------
void LatencyProtocol::setup()
{
Log::info("LatencyProtocol", "Ready !");
} // setup
//-----------------------------------------------------------------------------
/** Called when receiving a message. On the client side the message is a ping
* from the server, which is answered back. On the server the received message
* is a reply to a previous ping request. The server will keep track of
* average latency.
*/
bool LatencyProtocol::notifyEventAsynchronous(Event* event)
{
if (event->getType() != EVENT_TYPE_MESSAGE)
return true;
if(!checkDataSize(event, 5)) return true;
const NetworkString &data = event->data();
uint32_t request = data.getUInt8();
uint32_t sequence = data.getUInt32();
const std::vector<STKPeer*> &peers = STKHost::get()->getPeers();
assert(peers.size() > 0);
// Find the right peer id. The host id (i.e. each host sendings its
// host id) can not be used here, since host ids can have gaps (if a
// host should disconnect)
uint8_t peer_id = -1;
for (unsigned int i = 0; i < peers.size(); i++)
{
if (peers[i]->isSamePeer(event->getPeer()))
{
peer_id = i;
break;
}
}
if (request)
{
// Only a client should receive a request for a ping response
assert(NetworkConfig::get()->isClient());
NetworkString *response = getNetworkString(5);
// The '0' indicates a response to a ping request
response->addUInt8(0).addUInt32(sequence);
event->getPeer()->sendPacket(response, false);
delete response;
}
else // receive response to a ping request
{
// Only a server should receive this kind of message
assert(NetworkConfig::get()->isServer());
if (sequence >= m_pings[peer_id].size())
{
Log::warn("LatencyProtocol",
"The sequence# %u isn't known.", sequence);
return true;
}
double current_time = StkTime::getRealTime();
m_total_diff[peer_id] += current_time - m_pings[peer_id][sequence];
m_successed_pings[peer_id]++;
m_average_ping[peer_id] =
(int)((m_total_diff[peer_id]/m_successed_pings[peer_id])*1000.0);
Log::debug("LatencyProtocol",
"Peer %d sequence %d ping %u average %u at %lf",
peer_id, sequence,
(unsigned int)((current_time - m_pings[peer_id][sequence])*1000),
m_average_ping[peer_id],
StkTime::getRealTime());
}
return true;
} // notifyEventAsynchronous
//-----------------------------------------------------------------------------
/** Waits for the countdown to be started. On the server the start of the
* countdown is triggered by ServerLobby::finishedLoadingWorld(),
* which is called once all clients have confirmed that they are ready to
* start. The server will send a ping request to each client once a second,
* and include the information if the countdown has started (and its current
* value). On the client the countdown is started in notifyEvenAsynchronous()
* when a server ping is received that indicates that the countdown has
* started. The measured times can be used later to estimate the latency
* between server and client.
*/
void LatencyProtocol::asynchronousUpdate()
{
float current_time = float(StkTime::getRealTime());
if (NetworkConfig::get()->isServer() && current_time > m_last_time+1)
{
const std::vector<STKPeer*> &peers = STKHost::get()->getPeers();
for (unsigned int i = 0; i < peers.size(); i++)
{
NetworkString *ping_request =
getNetworkString(5);
ping_request->addUInt8(1).addUInt32(m_pings[i].size());
m_pings[i] [ m_pings_count ] = current_time;
peers[i]->sendPacket(ping_request, false);
delete ping_request;
} // for i M peers
m_last_time = current_time;
m_pings_count++;
} // if current_time > m_last_time + 0.1
} // asynchronousUpdate