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