-
Notifications
You must be signed in to change notification settings - Fork 8
/
server.cpp
341 lines (304 loc) · 12.2 KB
/
server.cpp
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
#include <iostream>
#include <vector>
#include <optional>
#include <thread>
#include <chrono>
#include <netinet/in.h>
#include <sys/socket.h>
#include <netdb.h>
#include <unistd.h>
#include <queue>
#include "common.h"
struct Input
{
uint32_t id;
Player player;
};
struct Client
{
sockaddr_in address;
std::queue<Input> queue;
bool regulateQueue;
size_t playerId;
std::chrono::steady_clock::time_point lastUpdate;
};
void receive(int &udpSocket, std::vector<Client> &clients, bool &running)
{
constexpr uint16_t PROTOCOL_VERSION = 1;
try
{
while (running)
{
char buffer[48];
struct sockaddr_in clientAddress;
socklen_t clientAddressLength = sizeof(clientAddress);
int recvLength = recvfrom(udpSocket, buffer, sizeof(buffer), 0, (struct sockaddr *)&clientAddress, &clientAddressLength);
if (recvLength < 1)
{
throw std::runtime_error("receiving input");
}
Client *client = nullptr;
for (Client &c : clients)
{
if (memcmp(&c.address, &clientAddress, sizeof(clientAddress)) == 0)
{
client = &c;
break;
}
}
if (client == nullptr)
{
if (clients.size() < 2)
{
const uint8_t playerId = clients.size() == 0 ? 0 : clients[0].playerId ^ 1;
clients.push_back(Client{.address = clientAddress, .regulateQueue = true, .playerId = playerId, .lastUpdate = std::chrono::steady_clock::now()});
// TODO: deal with packet loss
char buffer[3];
std::memcpy(buffer, &PROTOCOL_VERSION, 2);
buffer[2] = playerId;
sendto(udpSocket, buffer, sizeof(buffer), 0, (sockaddr *)&clientAddress, sizeof(clientAddress));
std::cout << "new client connected" << std::endl;
}
else
{
continue;
}
}
else
{
Input input;
std::memcpy(&input.id, buffer, 4);
std::memcpy(input.player.state.position.data(), buffer + 4, 12);
std::memcpy(input.player.state.velocity.data(), buffer + 16, 12);
std::memcpy(input.player.state.orientation.data(), buffer + 28, 12);
std::memcpy(&input.player.action.steering, buffer + 40, 4);
std::memcpy(&input.player.action.throttle, buffer + 44, 4);
client->queue.push(input);
client->lastUpdate = std::chrono::steady_clock::now();
}
}
}
catch (const std::exception &e)
{
std::cerr << "error: " << e.what() << std::endl;
}
running = false;
}
void publishServerAddress(std::string address, uint16_t port, std::vector<Client> &clients, bool &running)
{
int tcpSocket = -1;
try
{
constexpr int SERVER_PORT = 8080;
constexpr uint16_t PERIOD = 30;
const std::string addressesServerAddress = "hacker-league.molyz.app";
const struct hostent *hostEntry = gethostbyname(addressesServerAddress.c_str());
if (hostEntry == nullptr)
{
throw std::runtime_error("resolving hostname");
}
struct sockaddr_in serverAddress
{
};
serverAddress.sin_family = AF_INET;
std::memcpy(&serverAddress.sin_addr.s_addr, hostEntry->h_addr, hostEntry->h_length);
serverAddress.sin_port = htons(SERVER_PORT);
uint8_t time = PERIOD;
size_t lastNPlayers = clients.size();
std::cout << "Publishing address \"" << address << "\" and port \"" << port << "\" to public servers list" << std::endl;
while (running)
{
if (time < PERIOD && lastNPlayers == clients.size())
{
std::this_thread::sleep_for(std::chrono::seconds(1));
time++;
continue;
}
time = 0;
lastNPlayers = clients.size();
std::ostringstream bodyStream;
bodyStream << "{ \"address\": \"" << address << "\", "
<< "\"port\": " << port << ", "
<< "\"nPlayers\": " << clients.size() << " }";
std::string body = bodyStream.str();
std::ostringstream httpRequestStream;
httpRequestStream << "POST /publish HTTP/1.1\r\n"
<< "Host: " << addressesServerAddress << "\r\n"
<< "Content-Type: application/json\r\n"
<< "Content-Length: " << body.size() << "\r\n\r\n"
<< body;
std::string httpRequest = httpRequestStream.str();
tcpSocket = socket(AF_INET, SOCK_STREAM, 0);
if (tcpSocket < 0)
{
throw std::runtime_error("creating tcp socket");
}
if (connect(tcpSocket, (struct sockaddr *)&serverAddress, sizeof(serverAddress)) < 0)
{
throw std::runtime_error("connecting to the server");
}
if (send(tcpSocket, httpRequest.c_str(), httpRequest.size(), 0) < 0)
{
throw std::runtime_error("sending message");
}
char buffer[4096];
const int bytesReceived = recv(tcpSocket, buffer, sizeof(buffer), 0);
if (bytesReceived < 0)
{
throw std::runtime_error("receiving response");
}
close(tcpSocket);
}
}
catch (const std::exception &e)
{
std::cerr << "error: " << e.what() << std::endl;
}
if (tcpSocket > -1)
{
close(tcpSocket);
}
running = false;
}
int main(int argc, char *argv[])
{
bool running = true;
int udpSocket = -1;
std::optional<std::thread> receiveThread, tcpThread;
try
{
if (!(argc == 2 || argc == 4))
{
throw std::runtime_error("wrong number of arguments");
}
udpSocket = socket(AF_INET, SOCK_DGRAM, 0);
if (udpSocket < 0)
{
throw std::runtime_error("creating udp socket");
}
struct sockaddr_in serverAddress = {};
serverAddress.sin_family = AF_INET;
serverAddress.sin_addr.s_addr = INADDR_ANY;
serverAddress.sin_port = htons(std::stoi(argv[1]));
if (bind(udpSocket, (struct sockaddr *)&serverAddress, sizeof(serverAddress)) < 0)
{
throw std::runtime_error("binding udp socket");
}
std::vector<Client> clients;
receiveThread = std::thread(&receive, std::ref(udpSocket), std::ref(clients), std::ref(running));
if (argc == 4)
{
tcpThread = std::thread(&publishServerAddress, argv[2], std::stoi(argv[3]), std::ref(clients), std::ref(running));
}
std::cout << "Server listening on address \"0.0.0.0\" (all interfaces) and port \"" << argv[1] << "\"" << std::endl;
ObjectState ball = initialBall;
std::vector<Player> players = initialPlayers;
uint8_t scores[2];
constexpr uint FREQUENCY = 60;
constexpr float PERIOD = 1.f / FREQUENCY;
constexpr uint16_t GAME_DURATION = 300;
constexpr uint16_t TRANSITION_DURATION = 5;
constexpr uint8_t QUEUE_MAX = 2;
constexpr uint8_t MAX_TIME_CLIENT_IDLE = 5;
int64_t startTime = 0;
int64_t transitionTime = 0;
const auto period = std::chrono::duration_cast<std::chrono::microseconds>(std::chrono::duration<float>(PERIOD));
auto targetTime = std::chrono::high_resolution_clock::now();
while (running)
{
const int64_t currentTime = std::chrono::duration_cast<std::chrono::seconds>(std::chrono::high_resolution_clock::now().time_since_epoch()).count();
const int64_t duration = currentTime - startTime;
if (clients.size() == 2)
{
if (duration > GAME_DURATION)
{
startTime = currentTime + TRANSITION_DURATION;
transitionTime = currentTime;
ball = initialBall;
scores[0] = 0;
scores[1] = 0;
std::cout << "game reset" << std::endl;
}
}
else
{
startTime = 0;
}
const size_t nClients = clients.size();
clients.erase(std::remove_if(clients.begin(), clients.end(),
[](const Client &client)
{
return std::chrono::duration_cast<std::chrono::seconds>(std::chrono::steady_clock::now() - client.lastUpdate).count() > MAX_TIME_CLIENT_IDLE;
}),
clients.end());
if (nClients != clients.size())
std::cout << "time: " << duration << ", client disconnected" << std::endl;
std::vector<std::tuple<sockaddr_in *, size_t, uint32_t>> clientPlayerInputIds;
bool queueTooLong = false;
for (auto &[address, queue, regulateQueue, playerId, _] : clients)
{
if (!queue.empty())
{
if (queue.size() > QUEUE_MAX)
{
queueTooLong = true;
std::cout << "time: " << duration << ", queue too long" << std::endl;
}
const Input &input = queue.front();
players[playerId] = input.player;
clientPlayerInputIds.push_back({&address, playerId, input.id});
queue.pop();
}
}
for (const auto &[address, playerId, inputId] : clientPlayerInputIds)
{
const size_t otherPlayer = playerId ^ 1;
int64_t countdown = GAME_DURATION - currentTime + startTime;
int64_t transitionCountdown = TRANSITION_DURATION - currentTime + transitionTime;
if (transitionCountdown < 0)
transitionCountdown = 0;
if (countdown < 0)
countdown = 0;
char buffer[102];
std::memcpy(buffer, &inputId, 4);
std::memcpy(buffer + 4, players[otherPlayer].state.position.data(), 12);
std::memcpy(buffer + 16, players[otherPlayer].state.velocity.data(), 12);
std::memcpy(buffer + 28, players[otherPlayer].state.orientation.data(), 12);
std::memcpy(buffer + 40, &players[otherPlayer].action.steering, 4);
std::memcpy(buffer + 44, &players[otherPlayer].action.throttle, 4);
std::memcpy(buffer + 48, ball.position.data(), 12);
std::memcpy(buffer + 60, ball.velocity.data(), 12);
std::memcpy(buffer + 72, ball.orientation.data(), 12);
std::memcpy(buffer + 84, &countdown, 8);
std::memcpy(buffer + 92, &transitionCountdown, 8);
std::memcpy(buffer + 100, &scores, 2);
sendto(udpSocket, buffer, sizeof(buffer), 0, (sockaddr *)address, sizeof(*address));
}
const uint8_t oldScore = scores[0] + scores[1];
physicsStep(ball, players, true, PERIOD, scores);
if (clients.size() == 2 && scores[0] + scores[1] != oldScore)
{
transitionTime = currentTime;
startTime += TRANSITION_DURATION;
std::cout << "time: " << duration << ", score: " << (uint32_t)scores[0] << "-" << (uint32_t)scores[1] << std::endl;
}
if (!queueTooLong)
{
targetTime += period;
std::this_thread::sleep_until(targetTime);
}
}
}
catch (const std::exception &e)
{
std::cerr << "error: " << e.what() << std::endl;
}
running = false;
if (tcpThread)
tcpThread->join();
if (receiveThread)
receiveThread->join();
if (udpSocket > -1)
close(udpSocket);
return EXIT_SUCCESS;
}