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 Server::Server()
  59 {
  60         pthread_mutex_init(&mutex, NULL);
  61
  62         epoll_fd = epoll_create(1024);  // Size argument is ignored.
  63         if (epoll_fd == -1) {
  64                 perror("epoll_fd");
  65                 exit(1);
  66         }
  67 }
  68
  69 void Server::run()
  70 {
  71         should_stop = false;
  72
  73         // Joinable is already the default, but it's good to be certain.
  74         pthread_attr_t attr;
  75         pthread_attr_init(&attr);
  76         pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_JOINABLE);
  77         pthread_create(&worker_thread, &attr, Server::do_work_thunk, this);
  78 }
  79
  80 void Server::stop()
  81 {
  82         {
  83                 MutexLock lock(&mutex);
  84                 should_stop = true;
  85         }
  86
  87         if (pthread_join(worker_thread, NULL) == -1) {
  88                 perror("pthread_join");
  89                 exit(1);
  90         }
  91 }
  92
  93 void *Server::do_work_thunk(void *arg)
  94 {
  95         Server *server = static_cast<Server *>(arg);
  96         server->do_work();
  97         return NULL;
  98 }
  99
 100 void Server::do_work()
 101 {
 102         for ( ;; ) {
 103                 int nfds = epoll_wait(epoll_fd, events, EPOLL_MAX_EVENTS, EPOLL_TIMEOUT_MS);
 104                 if (nfds == -1) {
 105                         perror("epoll_wait");
 106                         exit(1);
 107                 }
 108
 109                 MutexLock lock(&mutex);  // We release the mutex between iterations.
 110
 111                 if (should_stop) {
 112                         return;
 113                 }
 114
 115                 for (int i = 0; i < nfds; ++i) {
 116                         int fd = events[i].data.fd;
 117                         assert(clients.count(fd) != 0);
 118                         Client *client = &clients[fd];
 119
 120                         if (events[i].events & (EPOLLERR | EPOLLRDHUP | EPOLLHUP)) {
 121                                 close_client(client);
 122                                 continue;
 123                         }
 124
 125                         process_client(client);
 126                 }
 127         }
 128 }
 129
 130 void Server::add_client(int sock)
 131 {
 132         MutexLock lock(&mutex);
 133         clients.insert(make_pair(sock, Client(sock)));
 134
 135         // Start listening on data from this socket.
 136         epoll_event ev;
 137         ev.events = EPOLLIN | EPOLLRDHUP;
 138         ev.data.fd = sock;
 139         if (epoll_ctl(epoll_fd, EPOLL_CTL_ADD, sock, &ev) == -1) {
 140                 perror("epoll_ctl(EPOLL_CTL_ADD)");
 141                 exit(1);
 142         }
 143 }
 144
 145 void Server::add_stream(const string &stream_id)
 146 {
 147         MutexLock lock(&mutex);
 148         streams.insert(make_pair(stream_id, Stream()));
 149 }
 150
 151 void Server::set_header(const string &stream_id, const string &header)
 152 {
 153         MutexLock lock(&mutex);
 154         assert(streams.count(stream_id) != 0);
 155         streams[stream_id].header = header;
 156 }
 157
 158 void Server::add_data(const string &stream_id, const char *data, size_t bytes)
 159 {
 160         if (bytes == 0) {
 161                 return;
 162         }
 163
 164         MutexLock lock(&mutex);
 165         assert(streams.count(stream_id) != 0);
 166         Stream *stream = &streams[stream_id];
 167         size_t pos = stream->data_size % BACKLOG_SIZE;
 168         stream->data_size += bytes;
 169
 170         if (pos + bytes > BACKLOG_SIZE) {
 171                 size_t to_copy = BACKLOG_SIZE - pos;
 172                 memcpy(stream->data + pos, data, to_copy);
 173                 data += to_copy;
 174                 bytes -= to_copy;
 175                 pos = 0;
 176         }
 177
 178         memcpy(stream->data + pos, data, bytes);
 179         wake_up_all_clients();
 180 }
 181
 182 void Server::process_client(Client *client)
 183 {
 184         switch (client->state) {
 185         case Client::READING_REQUEST: {
 186                 // Try to read more of the request.
 187                 char buf[1024];
 188                 int ret = read(client->sock, buf, sizeof(buf));
 189                 if (ret == -1) {
 190                         perror("read");
 191                         close_client(client);
 192                         return;
 193                 }
 194                 if (ret == 0) {
 195                         // No data? This really means that we were triggered for something else than
 196                         // POLLIN (which suggests a logic error in epoll).
 197                         fprintf(stderr, "WARNING: fd %d returned unexpectedly 0 bytes!\n", client->sock);
 198                         close_client(client);
 199                         return;
 200                 }
 201
 202                 // Guard against overlong requests gobbling up all of our space.
 203                 if (client->request.size() + ret > MAX_CLIENT_REQUEST) {
 204                         fprintf(stderr, "WARNING: fd %d sent overlong request!\n", client->sock);
 205                         close_client(client);
 206                         return;
 207                 }
 208
 209                 // See if we have \r\n\r\n anywhere in the request. We start three bytes
 210                 // before what we just appended, in case we just got the final character.
 211                 size_t existing_req_bytes = client->request.size();
 212                 client->request.append(string(buf, buf + ret));
 213
 214                 size_t start_at = (existing_req_bytes >= 3 ? existing_req_bytes - 3 : 0);
 215                 const char *ptr = reinterpret_cast<char *>(
 216                         memmem(client->request.data() + start_at, client->request.size() - start_at,
 217                                "\r\n\r\n", 4));
 218                 if (ptr == NULL) {
 219                         // OK, we don't have the entire header yet. Fine; we'll get it later.
 220                         return;
 221                 }
 222
 223                 if (ptr != client->request.data() + client->request.size() - 4) {
 224                         fprintf(stderr, "WARNING: fd %d had junk data after request!\n", client->sock);
 225                         close_client(client);
 226                         return;
 227                 }
 228
 229                 parse_request(client);
 230                 break;
 231         }
 232         case Client::SENDING_HEADER: {
 233                 int ret = write(client->sock,
 234                                 client->header.data() + client->header_bytes_sent,
 235                                 client->header.size() - client->header_bytes_sent);
 236                 if (ret == -1) {
 237                         perror("write");
 238                         close_client(client);
 239                         return;
 240                 }
 241
 242                 client->header_bytes_sent += ret;
 243                 assert(client->header_bytes_sent <= client->header.size());
 244
 245                 if (client->header_bytes_sent < client->header.size()) {
 246                         // We haven't sent all yet. Fine; we'll do that later.
 247                         return;
 248                 }
 249
 250                 // We're done sending the header! Clear the entire header to release some memory.
 251                 client->header.clear();
 252
 253                 // Start sending from the end. In other words, we won't send any of the backlog,
 254                 // but we'll start sending immediately as we get data.
 255                 client->state = Client::SENDING_DATA;
 256                 client->bytes_sent = streams[client->stream_id].data_size;
 257                 break;
 258         }
 259         case Client::SENDING_DATA: {
 260                 // See if there's some data we've lost. Ideally, we should drop to a block boundary,
 261                 // but resync will be the mux's problem.
 262                 const Stream &stream = streams[client->stream_id];
 263                 size_t bytes_to_send = stream.data_size - client->bytes_sent;
 264                 if (bytes_to_send > BACKLOG_SIZE) {
 265                         fprintf(stderr, "WARNING: fd %d lost %lld bytes, maybe too slow connection\n",
 266                                 client->sock,
 267                                 (long long int)(bytes_to_send - BACKLOG_SIZE));
 268                         client->bytes_sent = streams[client->stream_id].data_size - BACKLOG_SIZE;
 269                         bytes_to_send = BACKLOG_SIZE;
 270                 }
 271
 272                 // See if we need to split across the circular buffer.
 273                 ssize_t ret;
 274                 if ((client->bytes_sent % BACKLOG_SIZE) + bytes_to_send > BACKLOG_SIZE) {
 275                         size_t bytes_first_part = BACKLOG_SIZE - (client->bytes_sent % BACKLOG_SIZE);
 276
 277                         iovec iov[2];
 278                         iov[0].iov_base = const_cast<char *>(stream.data + (client->bytes_sent % BACKLOG_SIZE));
 279                         iov[0].iov_len = bytes_first_part;
 280
 281                         iov[1].iov_base = const_cast<char *>(stream.data);
 282                         iov[1].iov_len = bytes_to_send - bytes_first_part;
 283
 284                         ret = writev(client->sock, iov, 2);
 285                 } else {
 286                         ret = write(client->sock,
 287                                     stream.data + (client->bytes_sent % BACKLOG_SIZE),
 288                                     bytes_to_send);
 289                 }
 290                 if (ret == -1) {
 291                         perror("write/writev");
 292                         close_client(client);
 293                         return;
 294                 }
 295                 client->bytes_sent += ret;
 296
 297                 if (client->bytes_sent == stream.data_size) {
 298                         // We don't have any more data for this client, so put it to sleep.
 299                         put_client_to_sleep(client);
 300                 }
 301                 break;
 302         }
 303         default:
 304                 assert(false);
 305         }
 306 }
 307
 308 void Server::parse_request(Client *client)
 309 {
 310         // TODO: Actually parse the request. :-)
 311         client->stream_id = "stream";
 312         client->request.clear();
 313
 314         // Construct the header.
 315         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" +
 316                 streams[client->stream_id].header;
 317
 318         // Switch states.
 319         client->state = Client::SENDING_HEADER;
 320
 321         epoll_event ev;
 322         ev.events = EPOLLOUT | EPOLLRDHUP;
 323         ev.data.fd = client->sock;
 324
 325         if (epoll_ctl(epoll_fd, EPOLL_CTL_MOD, client->sock, &ev) == -1) {
 326                 perror("epoll_ctl(EPOLL_CTL_MOD)");
 327                 exit(1);
 328         }
 329 }
 330
 331 void Server::close_client(Client *client)
 332 {
 333         if (epoll_ctl(epoll_fd, EPOLL_CTL_DEL, client->sock, NULL) == -1) {
 334                 perror("epoll_ctl(EPOLL_CTL_DEL)");
 335                 exit(1);
 336         }
 337
 338         // This client could be sleeping, so we'll need to fix that. (Argh, O(n).)
 339         vector<int>::iterator new_end =
 340                 remove(sleeping_clients.begin(), sleeping_clients.end(), client->sock);
 341         sleeping_clients.erase(new_end, sleeping_clients.end());
 342
 343         // Bye-bye!
 344         close(client->sock);
 345         clients.erase(client->sock);
 346 }
 347
 348 void Server::put_client_to_sleep(Client *client)
 349 {
 350         epoll_event ev;
 351         ev.events = EPOLLRDHUP;
 352         ev.data.fd = client->sock;
 353
 354         if (epoll_ctl(epoll_fd, EPOLL_CTL_MOD, client->sock, &ev) == -1) {
 355                 perror("epoll_ctl(EPOLL_CTL_MOD)");
 356                 exit(1);
 357         }
 358
 359         sleeping_clients.push_back(client->sock);
 360 }
 361
 362 void Server::wake_up_all_clients()
 363 {
 364         for (unsigned i = 0; i < sleeping_clients.size(); ++i) {
 365                 epoll_event ev;
 366                 ev.events = EPOLLOUT | EPOLLRDHUP;
 367                 ev.data.fd = sleeping_clients[i];
 368                 if (epoll_ctl(epoll_fd, EPOLL_CTL_MOD, sleeping_clients[i], &ev) == -1) {
 369                         perror("epoll_ctl(EPOLL_CTL_MOD)");
 370                         exit(1);
 371                 }
 372         }
 373         sleeping_clients.clear();
 374 }