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
 205 void Server::add_data(const string &stream_id, const char *data, size_t bytes)
 206 {
 207         if (bytes == 0) {
 208                 return;
 209         }
 210
 211         MutexLock lock(&mutex);
 212         Stream *stream = find_stream(stream_id);
 213         size_t pos = stream->data_size % BACKLOG_SIZE;
 214         stream->data_size += bytes;
 215
 216         if (pos + bytes > BACKLOG_SIZE) {
 217                 size_t to_copy = BACKLOG_SIZE - pos;
 218                 memcpy(stream->data + pos, data, to_copy);
 219                 data += to_copy;
 220                 bytes -= to_copy;
 221                 pos = 0;
 222         }
 223
 224         memcpy(stream->data + pos, data, bytes);
 225         wake_up_all_clients();
 226 }
 227
 228 void Server::process_client(Client *client)
 229 {
 230         switch (client->state) {
 231         case Client::READING_REQUEST: {
 232                 // Try to read more of the request.
 233                 char buf[1024];
 234                 int ret = read(client->sock, buf, sizeof(buf));
 235                 if (ret == -1) {
 236                         perror("read");
 237                         close_client(client);
 238                         return;
 239                 }
 240                 if (ret == 0) {
 241                         // No data? This really means that we were triggered for something else than
 242                         // POLLIN (which suggests a logic error in epoll).
 243                         fprintf(stderr, "WARNING: fd %d returned unexpectedly 0 bytes!\n", client->sock);
 244                         close_client(client);
 245                         return;
 246                 }
 247
 248                 // Guard against overlong requests gobbling up all of our space.
 249                 if (client->request.size() + ret > MAX_CLIENT_REQUEST) {
 250                         fprintf(stderr, "WARNING: fd %d sent overlong request!\n", client->sock);
 251                         close_client(client);
 252                         return;
 253                 }
 254
 255                 // See if we have \r\n\r\n anywhere in the request. We start three bytes
 256                 // before what we just appended, in case we just got the final character.
 257                 size_t existing_req_bytes = client->request.size();
 258                 client->request.append(string(buf, buf + ret));
 259
 260                 size_t start_at = (existing_req_bytes >= 3 ? existing_req_bytes - 3 : 0);
 261                 const char *ptr = reinterpret_cast<char *>(
 262                         memmem(client->request.data() + start_at, client->request.size() - start_at,
 263                                "\r\n\r\n", 4));
 264                 if (ptr == NULL) {
 265                         // OK, we don't have the entire header yet. Fine; we'll get it later.
 266                         return;
 267                 }
 268
 269                 if (ptr != client->request.data() + client->request.size() - 4) {
 270                         fprintf(stderr, "WARNING: fd %d had junk data after request!\n", client->sock);
 271                         close_client(client);
 272                         return;
 273                 }
 274
 275                 parse_request(client);
 276                 break;
 277         }
 278         case Client::SENDING_HEADER: {
 279                 int ret = write(client->sock,
 280                                 client->header.data() + client->header_bytes_sent,
 281                                 client->header.size() - client->header_bytes_sent);
 282                 if (ret == -1) {
 283                         perror("write");
 284                         close_client(client);
 285                         return;
 286                 }
 287
 288                 client->header_bytes_sent += ret;
 289                 assert(client->header_bytes_sent <= client->header.size());
 290
 291                 if (client->header_bytes_sent < client->header.size()) {
 292                         // We haven't sent all yet. Fine; we'll do that later.
 293                         return;
 294                 }
 295
 296                 // We're done sending the header! Clear the entire header to release some memory.
 297                 client->header.clear();
 298
 299                 // Start sending from the end. In other words, we won't send any of the backlog,
 300                 // but we'll start sending immediately as we get data.
 301                 client->state = Client::SENDING_DATA;
 302                 client->bytes_sent = find_stream(client->stream_id)->data_size;
 303                 break;
 304         }
 305         case Client::SENDING_DATA: {
 306                 // See if there's some data we've lost. Ideally, we should drop to a block boundary,
 307                 // but resync will be the mux's problem.
 308                 const Stream &stream = *find_stream(client->stream_id);
 309                 size_t bytes_to_send = stream.data_size - client->bytes_sent;
 310                 if (bytes_to_send > BACKLOG_SIZE) {
 311                         fprintf(stderr, "WARNING: fd %d lost %lld bytes, maybe too slow connection\n",
 312                                 client->sock,
 313                                 (long long int)(bytes_to_send - BACKLOG_SIZE));
 314                         client->bytes_sent = find_stream(client->stream_id)->data_size - BACKLOG_SIZE;
 315                         bytes_to_send = BACKLOG_SIZE;
 316                 }
 317
 318                 // See if we need to split across the circular buffer.
 319                 ssize_t ret;
 320                 if ((client->bytes_sent % BACKLOG_SIZE) + bytes_to_send > BACKLOG_SIZE) {
 321                         size_t bytes_first_part = BACKLOG_SIZE - (client->bytes_sent % BACKLOG_SIZE);
 322
 323                         iovec iov[2];
 324                         iov[0].iov_base = const_cast<char *>(stream.data + (client->bytes_sent % BACKLOG_SIZE));
 325                         iov[0].iov_len = bytes_first_part;
 326
 327                         iov[1].iov_base = const_cast<char *>(stream.data);
 328                         iov[1].iov_len = bytes_to_send - bytes_first_part;
 329
 330                         ret = writev(client->sock, iov, 2);
 331                 } else {
 332                         ret = write(client->sock,
 333                                     stream.data + (client->bytes_sent % BACKLOG_SIZE),
 334                                     bytes_to_send);
 335                 }
 336                 if (ret == -1) {
 337                         perror("write/writev");
 338                         close_client(client);
 339                         return;
 340                 }
 341                 client->bytes_sent += ret;
 342
 343                 if (client->bytes_sent == stream.data_size) {
 344                         // We don't have any more data for this client, so put it to sleep.
 345                         put_client_to_sleep(client);
 346                 }
 347                 break;
 348         }
 349         default:
 350                 assert(false);
 351         }
 352 }
 353
 354 void Server::parse_request(Client *client)
 355 {
 356         // TODO: Actually parse the request. :-)
 357         client->stream_id = "stream";
 358         client->request.clear();
 359
 360         // Construct the header.
 361         client->header = "HTTP/1.0 200 OK\r\n  Content-type: video/x-flv\r\nCache-Control: no-cache\r\nContent-type: todo/fixme\r\n\r\n" +
 362                 find_stream(client->stream_id)->header;
 363
 364         // Switch states.
 365         client->state = Client::SENDING_HEADER;
 366
 367         epoll_event ev;
 368         ev.events = EPOLLOUT | EPOLLRDHUP;
 369         ev.data.u64 = 0;  // Keep Valgrind happy.
 370         ev.data.fd = client->sock;
 371
 372         if (epoll_ctl(epoll_fd, EPOLL_CTL_MOD, client->sock, &ev) == -1) {
 373                 perror("epoll_ctl(EPOLL_CTL_MOD)");
 374                 exit(1);
 375         }
 376 }
 377
 378 void Server::close_client(Client *client)
 379 {
 380         if (epoll_ctl(epoll_fd, EPOLL_CTL_DEL, client->sock, NULL) == -1) {
 381                 perror("epoll_ctl(EPOLL_CTL_DEL)");
 382                 exit(1);
 383         }
 384
 385         // This client could be sleeping, so we'll need to fix that. (Argh, O(n).)
 386         vector<int>::iterator new_end =
 387                 remove(sleeping_clients.begin(), sleeping_clients.end(), client->sock);
 388         sleeping_clients.erase(new_end, sleeping_clients.end());
 389
 390         // Bye-bye!
 391         close(client->sock);
 392         clients.erase(client->sock);
 393 }
 394
 395 void Server::put_client_to_sleep(Client *client)
 396 {
 397         epoll_event ev;
 398         ev.events = EPOLLRDHUP;
 399         ev.data.u64 = 0;  // Keep Valgrind happy.
 400         ev.data.fd = client->sock;
 401
 402         if (epoll_ctl(epoll_fd, EPOLL_CTL_MOD, client->sock, &ev) == -1) {
 403                 perror("epoll_ctl(EPOLL_CTL_MOD)");
 404                 exit(1);
 405         }
 406
 407         sleeping_clients.push_back(client->sock);
 408 }
 409
 410 void Server::wake_up_all_clients()
 411 {
 412         for (unsigned i = 0; i < sleeping_clients.size(); ++i) {
 413                 epoll_event ev;
 414                 ev.events = EPOLLOUT | EPOLLRDHUP;
 415                 ev.data.u64 = 0;  // Keep Valgrind happy.
 416                 ev.data.fd = sleeping_clients[i];
 417                 if (epoll_ctl(epoll_fd, EPOLL_CTL_MOD, sleeping_clients[i], &ev) == -1) {
 418                         perror("epoll_ctl(EPOLL_CTL_MOD)");
 419                         exit(1);
 420                 }
 421         }
 422         sleeping_clients.clear();
 423 }
 424
 425 Stream *Server::find_stream(const string &stream_id)
 426 {
 427         map<string, Stream *>::iterator it = streams.find(stream_id);
 428         assert(it != streams.end());
 429         return it->second;
 430 }