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         : state(Client::READING_REQUEST),
  27           header_bytes_sent(0),
  28           bytes_sent(0)
  29 {
  30         request.reserve(1024);
  31 }
  32
  33 Client::Client(const ClientProto &serialized)
  34         : sock(serialized.sock()),
  35           state(State(serialized.state())),
  36           request(serialized.request()),
  37           stream_id(serialized.stream_id()),
  38           header(serialized.header()),
  39           header_bytes_sent(serialized.header_bytes_sent()),
  40           bytes_sent(serialized.bytes_sent())
  41 {
  42 }
  43
  44 ClientProto Client::serialize() const
  45 {
  46         ClientProto serialized;
  47         serialized.set_sock(sock);
  48         serialized.set_state(state);
  49         serialized.set_request(request);
  50         serialized.set_stream_id(stream_id);
  51         serialized.set_header(header);
  52         serialized.set_header_bytes_sent(serialized.header_bytes_sent());
  53         serialized.set_bytes_sent(bytes_sent);
  54         return serialized;
  55 }
  56
  57 Server::Server()
  58 {
  59         pthread_mutex_init(&mutex, NULL);
  60
  61         epoll_fd = epoll_create(1024);  // Size argument is ignored.
  62         if (epoll_fd == -1) {
  63                 perror("epoll_fd");
  64                 exit(1);
  65         }
  66 }
  67
  68 void Server::run()
  69 {
  70         should_stop = false;
  71
  72         // Joinable is already the default, but it's good to be certain.
  73         pthread_attr_t attr;
  74         pthread_attr_init(&attr);
  75         pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_JOINABLE);
  76         pthread_create(&worker_thread, &attr, Server::do_work_thunk, this);
  77 }
  78
  79 void Server::stop()
  80 {
  81         {
  82                 MutexLock lock(&mutex);
  83                 should_stop = true;
  84         }
  85
  86         if (pthread_join(worker_thread, NULL) == -1) {
  87                 perror("pthread_join");
  88                 exit(1);
  89         }
  90 }
  91
  92 void *Server::do_work_thunk(void *arg)
  93 {
  94         Server *server = static_cast<Server *>(arg);
  95         server->do_work();
  96         return NULL;
  97 }
  98
  99 void Server::do_work()
 100 {
 101         for ( ;; ) {
 102                 int nfds = epoll_wait(epoll_fd, events, EPOLL_MAX_EVENTS, EPOLL_TIMEOUT_MS);
 103                 if (nfds == -1) {
 104                         perror("epoll_wait");
 105                         exit(1);
 106                 }
 107
 108                 MutexLock lock(&mutex);  // We release the mutex between iterations.
 109
 110                 if (should_stop) {
 111                         return;
 112                 }
 113
 114                 for (int i = 0; i < nfds; ++i) {
 115                         int fd = events[i].data.fd;
 116                         assert(clients.count(fd) != 0);
 117                         Client *client = &clients[fd];
 118
 119                         if (events[i].events & (EPOLLERR | EPOLLRDHUP | EPOLLHUP)) {
 120                                 close_client(client);
 121                                 continue;
 122                         }
 123
 124                         process_client(client);
 125                 }
 126         }
 127 }
 128
 129 void Server::add_client(int sock)
 130 {
 131         MutexLock lock(&mutex);
 132         clients.insert(make_pair(sock, Client(sock)));
 133
 134         // Start listening on data from this socket.
 135         epoll_event ev;
 136         ev.events = EPOLLIN | EPOLLRDHUP;
 137         ev.data.fd = sock;
 138         if (epoll_ctl(epoll_fd, EPOLL_CTL_ADD, sock, &ev) == -1) {
 139                 perror("epoll_ctl(EPOLL_CTL_ADD)");
 140                 exit(1);
 141         }
 142 }
 143
 144 void Server::add_stream(const string &stream_id)
 145 {
 146         MutexLock lock(&mutex);
 147         streams.insert(make_pair(stream_id, Stream()));
 148 }
 149
 150 void Server::set_header(const string &stream_id, const string &header)
 151 {
 152         MutexLock lock(&mutex);
 153         assert(streams.count(stream_id) != 0);
 154         streams[stream_id].header = header;
 155 }
 156
 157 void Server::add_data(const string &stream_id, const char *data, size_t bytes)
 158 {
 159         if (bytes == 0) {
 160                 return;
 161         }
 162
 163         MutexLock lock(&mutex);
 164         assert(streams.count(stream_id) != 0);
 165         Stream *stream = &streams[stream_id];
 166         size_t pos = stream->data_size % BACKLOG_SIZE;
 167         stream->data_size += bytes;
 168
 169         if (pos + bytes > BACKLOG_SIZE) {
 170                 size_t to_copy = BACKLOG_SIZE - pos;
 171                 memcpy(stream->data + pos, data, to_copy);
 172                 data += to_copy;
 173                 bytes -= to_copy;
 174                 pos = 0;
 175         }
 176
 177         memcpy(stream->data + pos, data, bytes);
 178         wake_up_all_clients();
 179 }
 180
 181 void Server::process_client(Client *client)
 182 {
 183         switch (client->state) {
 184         case Client::READING_REQUEST: {
 185                 // Try to read more of the request.
 186                 char buf[1024];
 187                 int ret = read(client->sock, buf, sizeof(buf));
 188                 if (ret == -1) {
 189                         perror("read");
 190                         close_client(client);
 191                         return;
 192                 }
 193                 if (ret == 0) {
 194                         // No data? This really means that we were triggered for something else than
 195                         // POLLIN (which suggests a logic error in epoll).
 196                         fprintf(stderr, "WARNING: fd %d returned unexpectedly 0 bytes!\n", client->sock);
 197                         close_client(client);
 198                         return;
 199                 }
 200
 201                 // Guard against overlong requests gobbling up all of our space.
 202                 if (client->request.size() + ret > MAX_CLIENT_REQUEST) {
 203                         fprintf(stderr, "WARNING: fd %d sent overlong request!\n", client->sock);
 204                         close_client(client);
 205                         return;
 206                 }
 207
 208                 // See if we have \r\n\r\n anywhere in the request. We start three bytes
 209                 // before what we just appended, in case we just got the final character.
 210                 size_t existing_req_bytes = client->request.size();
 211                 client->request.append(string(buf, buf + ret));
 212
 213                 size_t start_at = (existing_req_bytes >= 3 ? existing_req_bytes - 3 : 0);
 214                 const char *ptr = reinterpret_cast<char *>(
 215                         memmem(client->request.data() + start_at, client->request.size() - start_at,
 216                                "\r\n\r\n", 4));
 217                 if (ptr == NULL) {
 218                         // OK, we don't have the entire header yet. Fine; we'll get it later.
 219                         return;
 220                 }
 221
 222                 if (ptr != client->request.data() + client->request.size() - 4) {
 223                         fprintf(stderr, "WARNING: fd %d had junk data after request!\n", client->sock);
 224                         close_client(client);
 225                         return;
 226                 }
 227
 228                 parse_request(client);
 229                 break;
 230         }
 231         case Client::SENDING_HEADER: {
 232                 int ret = write(client->sock,
 233                                 client->header.data() + client->header_bytes_sent,
 234                                 client->header.size() - client->header_bytes_sent);
 235                 if (ret == -1) {
 236                         perror("write");
 237                         close_client(client);
 238                         return;
 239                 }
 240
 241                 client->header_bytes_sent += ret;
 242                 assert(client->header_bytes_sent <= client->header.size());
 243
 244                 if (client->header_bytes_sent < client->header.size()) {
 245                         // We haven't sent all yet. Fine; we'll do that later.
 246                         return;
 247                 }
 248
 249                 // We're done sending the header! Clear the entire header to release some memory.
 250                 client->header.clear();
 251
 252                 // Start sending from the end. In other words, we won't send any of the backlog,
 253                 // but we'll start sending immediately as we get data.
 254                 client->state = Client::SENDING_DATA;
 255                 client->bytes_sent = streams[client->stream_id].data_size;
 256                 break;
 257         }
 258         case Client::SENDING_DATA: {
 259                 // See if there's some data we've lost. Ideally, we should drop to a block boundary,
 260                 // but resync will be the mux's problem.
 261                 const Stream &stream = streams[client->stream_id];
 262                 size_t bytes_to_send = stream.data_size - client->bytes_sent;
 263                 if (bytes_to_send > BACKLOG_SIZE) {
 264                         fprintf(stderr, "WARNING: fd %d lost %lld bytes, maybe too slow connection\n",
 265                                 client->sock,
 266                                 (long long int)(bytes_to_send - BACKLOG_SIZE));
 267                         client->bytes_sent = streams[client->stream_id].data_size - BACKLOG_SIZE;
 268                         bytes_to_send = BACKLOG_SIZE;
 269                 }
 270
 271                 // See if we need to split across the circular buffer.
 272                 ssize_t ret;
 273                 if ((client->bytes_sent % BACKLOG_SIZE) + bytes_to_send > BACKLOG_SIZE) {
 274                         size_t bytes_first_part = BACKLOG_SIZE - (client->bytes_sent % BACKLOG_SIZE);
 275
 276                         iovec iov[2];
 277                         iov[0].iov_base = const_cast<char *>(stream.data + (client->bytes_sent % BACKLOG_SIZE));
 278                         iov[0].iov_len = bytes_first_part;
 279
 280                         iov[1].iov_base = const_cast<char *>(stream.data);
 281                         iov[1].iov_len = bytes_to_send - bytes_first_part;
 282
 283                         ret = writev(client->sock, iov, 2);
 284                 } else {
 285                         ret = write(client->sock,
 286                                     stream.data + (client->bytes_sent % BACKLOG_SIZE),
 287                                     bytes_to_send);
 288                 }
 289                 if (ret == -1) {
 290                         perror("write/writev");
 291                         close_client(client);
 292                         return;
 293                 }
 294                 client->bytes_sent += ret;
 295
 296                 if (client->bytes_sent == stream.data_size) {
 297                         // We don't have any more data for this client, so put it to sleep.
 298                         put_client_to_sleep(client);
 299                 }
 300                 break;
 301         }
 302         default:
 303                 assert(false);
 304         }
 305 }
 306
 307 void Server::parse_request(Client *client)
 308 {
 309         // TODO: Actually parse the request. :-)
 310         client->stream_id = "stream";
 311         client->request.clear();
 312
 313         // Construct the header.
 314         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" +
 315                 streams[client->stream_id].header;
 316
 317         // Switch states.
 318         client->state = Client::SENDING_HEADER;
 319
 320         epoll_event ev;
 321         ev.events = EPOLLOUT | EPOLLRDHUP;
 322         ev.data.fd = client->sock;
 323
 324         if (epoll_ctl(epoll_fd, EPOLL_CTL_MOD, client->sock, &ev) == -1) {
 325                 perror("epoll_ctl(EPOLL_CTL_MOD)");
 326                 exit(1);
 327         }
 328 }
 329
 330 void Server::close_client(Client *client)
 331 {
 332         if (epoll_ctl(epoll_fd, EPOLL_CTL_DEL, client->sock, NULL) == -1) {
 333                 perror("epoll_ctl(EPOLL_CTL_DEL)");
 334                 exit(1);
 335         }
 336
 337         // This client could be sleeping, so we'll need to fix that. (Argh, O(n).)
 338         vector<int>::iterator new_end =
 339                 remove(sleeping_clients.begin(), sleeping_clients.end(), client->sock);
 340         sleeping_clients.erase(new_end, sleeping_clients.end());
 341
 342         // Bye-bye!
 343         close(client->sock);
 344         clients.erase(client->sock);
 345 }
 346
 347 void Server::put_client_to_sleep(Client *client)
 348 {
 349         epoll_event ev;
 350         ev.events = EPOLLRDHUP;
 351         ev.data.fd = client->sock;
 352
 353         if (epoll_ctl(epoll_fd, EPOLL_CTL_MOD, client->sock, &ev) == -1) {
 354                 perror("epoll_ctl(EPOLL_CTL_MOD)");
 355                 exit(1);
 356         }
 357
 358         sleeping_clients.push_back(client->sock);
 359 }
 360
 361 void Server::wake_up_all_clients()
 362 {
 363         for (unsigned i = 0; i < sleeping_clients.size(); ++i) {
 364                 epoll_event ev;
 365                 ev.events = EPOLLOUT | EPOLLRDHUP;
 366                 ev.data.fd = sleeping_clients[i];
 367                 if (epoll_ctl(epoll_fd, EPOLL_CTL_MOD, sleeping_clients[i], &ev) == -1) {
 368                         perror("epoll_ctl(EPOLL_CTL_MOD)");
 369                         exit(1);
 370                 }
 371         }
 372         sleeping_clients.clear();
 373 }