git.sesse.net Git - cubemap/blob - server.cpp

   1 #include <stdio.h>
   2 #include <string.h>
   3 #include <stdint.h>
   4 #include <assert.h>
   5 #include <arpa/inet.h>
   6 #include <curl/curl.h>
   7 #include <sys/socket.h>
   8 #include <pthread.h>
   9 #include <sys/types.h>
  10 #include <sys/ioctl.h>
  11 #include <sys/epoll.h>
  12 #include <errno.h>
  13 #include <vector>
  14 #include <string>
  15 #include <map>
  16 #include <algorithm>
  17
  18 #include "metacube.h"
  19 #include "server.h"
  20 #include "mutexlock.h"
  21 #include "state.pb.h"
  22
  23 using namespace std;
  24
  25 Client::Client(int sock)
  26         : sock(sock),
  27           state(Client::READING_REQUEST),
  28           header_bytes_sent(0),
  29           bytes_sent(0)
  30 {
  31         request.reserve(1024);
  32 }
  33
  34 Client::Client(const ClientProto &serialized)
  35         : sock(serialized.sock()),
  36           state(State(serialized.state())),
  37           request(serialized.request()),
  38           stream_id(serialized.stream_id()),
  39           header(serialized.header()),
  40           header_bytes_sent(serialized.header_bytes_sent()),
  41           bytes_sent(serialized.bytes_sent())
  42 {
  43 }
  44
  45 ClientProto Client::serialize() const
  46 {
  47         ClientProto serialized;
  48         serialized.set_sock(sock);
  49         serialized.set_state(state);
  50         serialized.set_request(request);
  51         serialized.set_stream_id(stream_id);
  52         serialized.set_header(header);
  53         serialized.set_header_bytes_sent(serialized.header_bytes_sent());
  54         serialized.set_bytes_sent(bytes_sent);
  55         return serialized;
  56 }
  57
  58 Stream::Stream(const string &stream_id)
  59         : stream_id(stream_id),
  60           data(new char[BACKLOG_SIZE]),
  61           data_size(0)
  62 {
  63         memset(data, 0, BACKLOG_SIZE);
  64 }
  65
  66 Stream::~Stream()
  67 {
  68         delete[] data;
  69 }
  70
  71 Stream::Stream(const StreamProto &serialized)
  72         : stream_id(serialized.stream_id()),
  73           header(serialized.header()),
  74           data(new char[BACKLOG_SIZE]),
  75           data_size(serialized.data_size())
  76 {
  77         assert(serialized.data().size() == BACKLOG_SIZE);
  78         memcpy(data, serialized.data().data(), BACKLOG_SIZE);
  79 }
  80
  81 StreamProto Stream::serialize() const
  82 {
  83         StreamProto serialized;
  84         serialized.set_header(header);
  85         serialized.set_data(string(data, data + BACKLOG_SIZE));
  86         serialized.set_data_size(data_size);
  87         serialized.set_stream_id(stream_id);
  88         return serialized;
  89 }
  90
  91 Server::Server()
  92 {
  93         pthread_mutex_init(&mutex, NULL);
  94
  95         epoll_fd = epoll_create(1024);  // Size argument is ignored.
  96         if (epoll_fd == -1) {
  97                 perror("epoll_fd");
  98                 exit(1);
  99         }
 100 }
 101
 102 Server::~Server()
 103 {
 104         close(epoll_fd);
 105 }
 106
 107 void Server::run()
 108 {
 109         should_stop = false;
 110
 111         // Joinable is already the default, but it's good to be certain.
 112         pthread_attr_t attr;
 113         pthread_attr_init(&attr);
 114         pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_JOINABLE);
 115         pthread_create(&worker_thread, &attr, Server::do_work_thunk, this);
 116 }
 117
 118 void Server::stop()
 119 {
 120         {
 121                 MutexLock lock(&mutex);
 122                 should_stop = true;
 123         }
 124
 125         if (pthread_join(worker_thread, NULL) == -1) {
 126                 perror("pthread_join");
 127                 exit(1);
 128         }
 129 }
 130
 131 void *Server::do_work_thunk(void *arg)
 132 {
 133         Server *server = static_cast<Server *>(arg);
 134         server->do_work();
 135         return NULL;
 136 }
 137
 138 void Server::do_work()
 139 {
 140         for ( ;; ) {
 141                 int nfds = epoll_wait(epoll_fd, events, EPOLL_MAX_EVENTS, EPOLL_TIMEOUT_MS);
 142                 if (nfds == -1) {
 143                         perror("epoll_wait");
 144                         exit(1);
 145                 }
 146
 147                 MutexLock lock(&mutex);  // We release the mutex between iterations.
 148
 149                 if (should_stop) {
 150                         return;
 151                 }
 152
 153                 for (int i = 0; i < nfds; ++i) {
 154                         int fd = events[i].data.fd;
 155                         assert(clients.count(fd) != 0);
 156                         Client *client = &clients[fd];
 157
 158                         if (events[i].events & (EPOLLERR | EPOLLRDHUP | EPOLLHUP)) {
 159                                 close_client(client);
 160                                 continue;
 161                         }
 162
 163                         process_client(client);
 164                 }
 165         }
 166 }
 167
 168 CubemapStateProto Server::serialize() const
 169 {
 170         CubemapStateProto serialized;
 171         for (map<int, Client>::const_iterator client_it = clients.begin();
 172              client_it != clients.end();
 173              ++client_it) {
 174                 serialized.add_clients()->MergeFrom(client_it->second.serialize());
 175         }
 176         for (map<string, Stream *>::const_iterator stream_it = streams.begin();
 177              stream_it != streams.end();
 178              ++stream_it) {
 179                 serialized.add_streams()->MergeFrom(stream_it->second->serialize());
 180         }
 181         return serialized;
 182 }
 183
 184 void Server::add_client(int sock)
 185 {
 186         MutexLock lock(&mutex);
 187         clients.insert(make_pair(sock, Client(sock)));
 188
 189         // Start listening on data from this socket.
 190         epoll_event ev;
 191         ev.events = EPOLLIN | EPOLLRDHUP;
 192         ev.data.u64 = 0;  // Keep Valgrind happy.
 193         ev.data.fd = sock;
 194         if (epoll_ctl(epoll_fd, EPOLL_CTL_ADD, sock, &ev) == -1) {
 195                 perror("epoll_ctl(EPOLL_CTL_ADD)");
 196                 exit(1);
 197         }
 198 }
 199
 200 void Server::add_client_from_serialized(const ClientProto &client)
 201 {
 202         MutexLock lock(&mutex);
 203         clients.insert(make_pair(client.sock(), Client(client)));
 204
 205         // Start listening on data from this socket.
 206         epoll_event ev;
 207         if (client.state() == Client::READING_REQUEST) {
 208                 ev.events = EPOLLIN | EPOLLRDHUP;
 209         } else {
 210                 // If we don't have more data for this client, we'll be putting it into
 211                 // the sleeping array again soon.
 212                 ev.events = EPOLLOUT | EPOLLRDHUP;
 213         }
 214         ev.data.u64 = 0;  // Keep Valgrind happy.
 215         ev.data.fd = client.sock();
 216         if (epoll_ctl(epoll_fd, EPOLL_CTL_ADD, client.sock(), &ev) == -1) {
 217                 perror("epoll_ctl(EPOLL_CTL_ADD)");
 218                 exit(1);
 219         }
 220 }
 221
 222 void Server::add_stream(const string &stream_id)
 223 {
 224         MutexLock lock(&mutex);
 225         streams.insert(make_pair(stream_id, new Stream(stream_id)));
 226 }
 227
 228 void Server::add_stream_from_serialized(const StreamProto &stream)
 229 {
 230         MutexLock lock(&mutex);
 231         streams.insert(make_pair(stream.stream_id(), new Stream(stream)));
 232 }
 233
 234 void Server::set_header(const string &stream_id, const string &header)
 235 {
 236         MutexLock lock(&mutex);
 237         find_stream(stream_id)->header = header;
 238
 239         // If there are clients we haven't sent anything to yet, we should give
 240         // them the header, so push back into the SENDING_HEADER state.
 241         for (map<int, Client>::iterator client_it = clients.begin();
 242              client_it != clients.end();
 243              ++client_it) {
 244                 Client *client = &client_it->second;
 245                 if (client->state == Client::SENDING_DATA &&
 246                     client->bytes_sent == 0) {
 247                         construct_header(client);
 248                 }
 249         }
 250 }
 251
 252 void Server::add_data(const string &stream_id, const char *data, size_t bytes)
 253 {
 254         if (bytes == 0) {
 255                 return;
 256         }
 257
 258         MutexLock lock(&mutex);
 259         Stream *stream = find_stream(stream_id);
 260         size_t pos = stream->data_size % BACKLOG_SIZE;
 261         stream->data_size += bytes;
 262
 263         if (pos + bytes > BACKLOG_SIZE) {
 264                 size_t to_copy = BACKLOG_SIZE - pos;
 265                 memcpy(stream->data + pos, data, to_copy);
 266                 data += to_copy;
 267                 bytes -= to_copy;
 268                 pos = 0;
 269         }
 270
 271         memcpy(stream->data + pos, data, bytes);
 272         wake_up_all_clients();
 273 }
 274
 275 void Server::process_client(Client *client)
 276 {
 277         switch (client->state) {
 278         case Client::READING_REQUEST: {
 279                 // Try to read more of the request.
 280                 char buf[1024];
 281                 int ret = read(client->sock, buf, sizeof(buf));
 282                 if (ret == -1) {
 283                         perror("read");
 284                         close_client(client);
 285                         return;
 286                 }
 287                 if (ret == 0) {
 288                         // No data? This really means that we were triggered for something else than
 289                         // POLLIN (which suggests a logic error in epoll).
 290                         fprintf(stderr, "WARNING: fd %d returned unexpectedly 0 bytes!\n", client->sock);
 291                         close_client(client);
 292                         return;
 293                 }
 294
 295                 // Guard against overlong requests gobbling up all of our space.
 296                 if (client->request.size() + ret > MAX_CLIENT_REQUEST) {
 297                         fprintf(stderr, "WARNING: fd %d sent overlong request!\n", client->sock);
 298                         close_client(client);
 299                         return;
 300                 }
 301
 302                 // See if we have \r\n\r\n anywhere in the request. We start three bytes
 303                 // before what we just appended, in case we just got the final character.
 304                 size_t existing_req_bytes = client->request.size();
 305                 client->request.append(string(buf, buf + ret));
 306
 307                 size_t start_at = (existing_req_bytes >= 3 ? existing_req_bytes - 3 : 0);
 308                 const char *ptr = reinterpret_cast<char *>(
 309                         memmem(client->request.data() + start_at, client->request.size() - start_at,
 310                                "\r\n\r\n", 4));
 311                 if (ptr == NULL) {
 312                         // OK, we don't have the entire header yet. Fine; we'll get it later.
 313                         return;
 314                 }
 315
 316                 if (ptr != client->request.data() + client->request.size() - 4) {
 317                         fprintf(stderr, "WARNING: fd %d had junk data after request!\n", client->sock);
 318                         close_client(client);
 319                         return;
 320                 }
 321
 322                 parse_request(client);
 323                 construct_header(client);
 324                 break;
 325         }
 326         case Client::SENDING_HEADER: {
 327                 int ret = write(client->sock,
 328                                 client->header.data() + client->header_bytes_sent,
 329                                 client->header.size() - client->header_bytes_sent);
 330                 if (ret == -1) {
 331                         perror("write");
 332                         close_client(client);
 333                         return;
 334                 }
 335
 336                 client->header_bytes_sent += ret;
 337                 assert(client->header_bytes_sent <= client->header.size());
 338
 339                 if (client->header_bytes_sent < client->header.size()) {
 340                         // We haven't sent all yet. Fine; we'll do that later.
 341                         return;
 342                 }
 343
 344                 // We're done sending the header! Clear the entire header to release some memory.
 345                 client->header.clear();
 346
 347                 // Start sending from the end. In other words, we won't send any of the backlog,
 348                 // but we'll start sending immediately as we get data.
 349                 client->state = Client::SENDING_DATA;
 350                 client->bytes_sent = find_stream(client->stream_id)->data_size;
 351                 break;
 352         }
 353         case Client::SENDING_DATA: {
 354                 // See if there's some data we've lost. Ideally, we should drop to a block boundary,
 355                 // but resync will be the mux's problem.
 356                 const Stream &stream = *find_stream(client->stream_id);
 357                 size_t bytes_to_send = stream.data_size - client->bytes_sent;
 358                 if (bytes_to_send > BACKLOG_SIZE) {
 359                         fprintf(stderr, "WARNING: fd %d lost %lld bytes, maybe too slow connection\n",
 360                                 client->sock,
 361                                 (long long int)(bytes_to_send - BACKLOG_SIZE));
 362                         client->bytes_sent = find_stream(client->stream_id)->data_size - BACKLOG_SIZE;
 363                         bytes_to_send = BACKLOG_SIZE;
 364                 }
 365
 366                 // See if we need to split across the circular buffer.
 367                 ssize_t ret;
 368                 if ((client->bytes_sent % BACKLOG_SIZE) + bytes_to_send > BACKLOG_SIZE) {
 369                         size_t bytes_first_part = BACKLOG_SIZE - (client->bytes_sent % BACKLOG_SIZE);
 370
 371                         iovec iov[2];
 372                         iov[0].iov_base = const_cast<char *>(stream.data + (client->bytes_sent % BACKLOG_SIZE));
 373                         iov[0].iov_len = bytes_first_part;
 374
 375                         iov[1].iov_base = const_cast<char *>(stream.data);
 376                         iov[1].iov_len = bytes_to_send - bytes_first_part;
 377
 378                         ret = writev(client->sock, iov, 2);
 379                 } else {
 380                         ret = write(client->sock,
 381                                     stream.data + (client->bytes_sent % BACKLOG_SIZE),
 382                                     bytes_to_send);
 383                 }
 384                 if (ret == -1) {
 385                         perror("write/writev");
 386                         close_client(client);
 387                         return;
 388                 }
 389                 client->bytes_sent += ret;
 390
 391                 if (client->bytes_sent == stream.data_size) {
 392                         // We don't have any more data for this client, so put it to sleep.
 393                         put_client_to_sleep(client);
 394                 }
 395                 break;
 396         }
 397         default:
 398                 assert(false);
 399         }
 400 }
 401
 402 void Server::parse_request(Client *client)
 403 {
 404         // TODO: Actually parse the request. :-)
 405         client->stream_id = "stream";
 406         client->request.clear();
 407 }
 408
 409 void Server::construct_header(Client *client)
 410 {
 411         client->header = "HTTP/1.0 200 OK\r\nContent-type: video/x-flv\r\nCache-Control: no-cache\r\n\r\n" +
 412                 find_stream(client->stream_id)->header;
 413
 414         // Switch states.
 415         client->state = Client::SENDING_HEADER;
 416
 417         epoll_event ev;
 418         ev.events = EPOLLOUT | EPOLLRDHUP;
 419         ev.data.u64 = 0;  // Keep Valgrind happy.
 420         ev.data.fd = client->sock;
 421
 422         if (epoll_ctl(epoll_fd, EPOLL_CTL_MOD, client->sock, &ev) == -1) {
 423                 perror("epoll_ctl(EPOLL_CTL_MOD)");
 424                 exit(1);
 425         }
 426 }
 427
 428 void Server::close_client(Client *client)
 429 {
 430         if (epoll_ctl(epoll_fd, EPOLL_CTL_DEL, client->sock, NULL) == -1) {
 431                 perror("epoll_ctl(EPOLL_CTL_DEL)");
 432                 exit(1);
 433         }
 434
 435         // This client could be sleeping, so we'll need to fix that. (Argh, O(n).)
 436         vector<int>::iterator new_end =
 437                 remove(sleeping_clients.begin(), sleeping_clients.end(), client->sock);
 438         sleeping_clients.erase(new_end, sleeping_clients.end());
 439
 440         // Bye-bye!
 441         close(client->sock);
 442         clients.erase(client->sock);
 443 }
 444
 445 void Server::put_client_to_sleep(Client *client)
 446 {
 447         epoll_event ev;
 448         ev.events = EPOLLRDHUP;
 449         ev.data.u64 = 0;  // Keep Valgrind happy.
 450         ev.data.fd = client->sock;
 451
 452         if (epoll_ctl(epoll_fd, EPOLL_CTL_MOD, client->sock, &ev) == -1) {
 453                 perror("epoll_ctl(EPOLL_CTL_MOD)");
 454                 exit(1);
 455         }
 456
 457         sleeping_clients.push_back(client->sock);
 458 }
 459
 460 void Server::wake_up_all_clients()
 461 {
 462         for (unsigned i = 0; i < sleeping_clients.size(); ++i) {
 463                 epoll_event ev;
 464                 ev.events = EPOLLOUT | EPOLLRDHUP;
 465                 ev.data.u64 = 0;  // Keep Valgrind happy.
 466                 ev.data.fd = sleeping_clients[i];
 467                 if (epoll_ctl(epoll_fd, EPOLL_CTL_MOD, sleeping_clients[i], &ev) == -1) {
 468                         perror("epoll_ctl(EPOLL_CTL_MOD)");
 469                         exit(1);
 470                 }
 471         }
 472         sleeping_clients.clear();
 473 }
 474
 475 Stream *Server::find_stream(const string &stream_id)
 476 {
 477         map<string, Stream *>::iterator it = streams.find(stream_id);
 478         assert(it != streams.end());
 479         return it->second;
 480 }