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
  22 using namespace std;
  23
  24 Client::Client(int sock)
  25         : state(Client::READING_REQUEST),
  26           header_bytes_sent(0),
  27           bytes_sent(0)
  28 {
  29         request.reserve(1024);
  30 }
  31
  32 Server::Server()
  33 {
  34         pthread_mutex_init(&mutex, NULL);
  35
  36         epoll_fd = epoll_create(1024);  // Size argument is ignored.
  37         if (epoll_fd == -1) {
  38                 perror("epoll_fd");
  39                 exit(1);
  40         }
  41 }
  42
  43 void Server::run()
  44 {
  45         should_stop = false;
  46
  47         // Joinable is already the default, but it's good to be certain.
  48         pthread_attr_t attr;
  49         pthread_attr_init(&attr);
  50         pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_JOINABLE);
  51         pthread_create(&worker_thread, &attr, Server::do_work_thunk, this);
  52 }
  53
  54 void Server::stop()
  55 {
  56         {
  57                 MutexLock lock(&mutex);
  58                 should_stop = true;
  59         }
  60
  61         if (pthread_join(worker_thread, NULL) == -1) {
  62                 perror("pthread_join");
  63                 exit(1);
  64         }
  65 }
  66
  67 void *Server::do_work_thunk(void *arg)
  68 {
  69         Server *server = static_cast<Server *>(arg);
  70         server->do_work();
  71         return NULL;
  72 }
  73
  74 void Server::do_work()
  75 {
  76         for ( ;; ) {
  77                 int nfds = epoll_wait(epoll_fd, events, EPOLL_MAX_EVENTS, EPOLL_TIMEOUT_MS);
  78                 if (nfds == -1) {
  79                         perror("epoll_wait");
  80                         exit(1);
  81                 }
  82
  83                 MutexLock lock(&mutex);  // We release the mutex between iterations.
  84
  85                 if (should_stop) {
  86                         return;
  87                 }
  88
  89                 for (int i = 0; i < nfds; ++i) {
  90                         int fd = events[i].data.fd;
  91                         assert(clients.count(fd) != 0);
  92                         Client *client = &clients[fd];
  93
  94                         if (events[i].events & (EPOLLERR | EPOLLRDHUP | EPOLLHUP)) {
  95                                 close_client(client);
  96                                 continue;
  97                         }
  98
  99                         process_client(client);
 100                 }
 101         }
 102 }
 103
 104 void Server::add_client(int sock)
 105 {
 106         MutexLock lock(&mutex);
 107         clients.insert(make_pair(sock, Client(sock)));
 108
 109         // Start listening on data from this socket.
 110         epoll_event ev;
 111         ev.events = EPOLLIN | EPOLLRDHUP;
 112         ev.data.fd = sock;
 113         if (epoll_ctl(epoll_fd, EPOLL_CTL_ADD, sock, &ev) == -1) {
 114                 perror("epoll_ctl(EPOLL_CTL_ADD)");
 115                 exit(1);
 116         }
 117 }
 118
 119 void Server::add_stream(const string &stream_id)
 120 {
 121         MutexLock lock(&mutex);
 122         streams.insert(make_pair(stream_id, Stream()));
 123 }
 124
 125 void Server::set_header(const string &stream_id, const string &header)
 126 {
 127         MutexLock lock(&mutex);
 128         assert(streams.count(stream_id) != 0);
 129         streams[stream_id].header = header;
 130 }
 131
 132 void Server::add_data(const string &stream_id, const char *data, size_t bytes)
 133 {
 134         if (bytes == 0) {
 135                 return;
 136         }
 137
 138         MutexLock lock(&mutex);
 139         assert(streams.count(stream_id) != 0);
 140         Stream *stream = &streams[stream_id];
 141         size_t pos = stream->data_size % BACKLOG_SIZE;
 142         stream->data_size += bytes;
 143
 144         if (pos + bytes > BACKLOG_SIZE) {
 145                 size_t to_copy = BACKLOG_SIZE - pos;
 146                 memcpy(stream->data + pos, data, to_copy);
 147                 data += to_copy;
 148                 bytes -= to_copy;
 149                 pos = 0;
 150         }
 151
 152         memcpy(stream->data + pos, data, bytes);
 153         wake_up_all_clients();
 154 }
 155
 156 void Server::process_client(Client *client)
 157 {
 158         switch (client->state) {
 159         case Client::READING_REQUEST: {
 160                 // Try to read more of the request.
 161                 char buf[1024];
 162                 int ret = read(client->sock, buf, sizeof(buf));
 163                 if (ret == -1) {
 164                         perror("read");
 165                         close_client(client);
 166                         return;
 167                 }
 168                 if (ret == 0) {
 169                         // No data? This really means that we were triggered for something else than
 170                         // POLLIN (which suggests a logic error in epoll).
 171                         fprintf(stderr, "WARNING: fd %d returned unexpectedly 0 bytes!\n", client->sock);
 172                         close_client(client);
 173                         return;
 174                 }
 175
 176                 // Guard against overlong requests gobbling up all of our space.
 177                 if (client->request.size() + ret > MAX_CLIENT_REQUEST) {
 178                         fprintf(stderr, "WARNING: fd %d sent overlong request!\n", client->sock);
 179                         close_client(client);
 180                         return;
 181                 }
 182
 183                 // See if we have \r\n\r\n anywhere in the request. We start three bytes
 184                 // before what we just appended, in case we just got the final character.
 185                 size_t existing_req_bytes = client->request.size();
 186                 client->request.append(string(buf, buf + ret));
 187
 188                 size_t start_at = (existing_req_bytes >= 3 ? existing_req_bytes - 3 : 0);
 189                 const char *ptr = reinterpret_cast<char *>(
 190                         memmem(client->request.data() + start_at, client->request.size() - start_at,
 191                                "\r\n\r\n", 4));
 192                 if (ptr == NULL) {
 193                         // OK, we don't have the entire header yet. Fine; we'll get it later.
 194                         return;
 195                 }
 196
 197                 if (ptr != client->request.data() + client->request.size() - 4) {
 198                         fprintf(stderr, "WARNING: fd %d had junk data after request!\n", client->sock);
 199                         close_client(client);
 200                         return;
 201                 }
 202
 203                 parse_request(client);
 204                 break;
 205         }
 206         case Client::SENDING_HEADER: {
 207                 int ret = write(client->sock,
 208                                 client->header.data() + client->header_bytes_sent,
 209                                 client->header.size() - client->header_bytes_sent);
 210                 if (ret == -1) {
 211                         perror("write");
 212                         close_client(client);
 213                         return;
 214                 }
 215
 216                 client->header_bytes_sent += ret;
 217                 assert(client->header_bytes_sent <= client->header.size());
 218
 219                 if (client->header_bytes_sent < client->header.size()) {
 220                         // We haven't sent all yet. Fine; we'll do that later.
 221                         return;
 222                 }
 223
 224                 // We're done sending the header! Clear the entire header to release some memory.
 225                 client->header.clear();
 226
 227                 // Start sending from the end. In other words, we won't send any of the backlog,
 228                 // but we'll start sending immediately as we get data.
 229                 client->state = Client::SENDING_DATA;
 230                 client->bytes_sent = streams[client->stream_id].data_size;
 231                 break;
 232         }
 233         case Client::SENDING_DATA: {
 234                 // See if there's some data we've lost. Ideally, we should drop to a block boundary,
 235                 // but resync will be the mux's problem.
 236                 const Stream &stream = streams[client->stream_id];
 237                 size_t bytes_to_send = stream.data_size - client->bytes_sent;
 238                 if (bytes_to_send > BACKLOG_SIZE) {
 239                         fprintf(stderr, "WARNING: fd %d lost %lld bytes, maybe too slow connection\n",
 240                                 client->sock,
 241                                 (long long int)(bytes_to_send - BACKLOG_SIZE));
 242                         client->bytes_sent = streams[client->stream_id].data_size - BACKLOG_SIZE;
 243                         bytes_to_send = BACKLOG_SIZE;
 244                 }
 245
 246                 // See if we need to split across the circular buffer.
 247                 ssize_t ret;
 248                 if ((client->bytes_sent % BACKLOG_SIZE) + bytes_to_send > BACKLOG_SIZE) {
 249                         size_t bytes_first_part = BACKLOG_SIZE - (client->bytes_sent % BACKLOG_SIZE);
 250
 251                         iovec iov[2];
 252                         iov[0].iov_base = const_cast<char *>(stream.data + (client->bytes_sent % BACKLOG_SIZE));
 253                         iov[0].iov_len = bytes_first_part;
 254
 255                         iov[1].iov_base = const_cast<char *>(stream.data);
 256                         iov[1].iov_len = bytes_to_send - bytes_first_part;
 257
 258                         ret = writev(client->sock, iov, 2);
 259                 } else {
 260                         ret = write(client->sock,
 261                                     stream.data + (client->bytes_sent % BACKLOG_SIZE),
 262                                     bytes_to_send);
 263                 }
 264                 if (ret == -1) {
 265                         perror("write/writev");
 266                         close_client(client);
 267                         return;
 268                 }
 269                 client->bytes_sent += ret;
 270
 271                 if (client->bytes_sent == stream.data_size) {
 272                         // We don't have any more data for this client, so put it to sleep.
 273                         put_client_to_sleep(client);
 274                 }
 275                 break;
 276         }
 277         default:
 278                 assert(false);
 279         }
 280 }
 281
 282 void Server::parse_request(Client *client)
 283 {
 284         // TODO: Actually parse the request. :-)
 285         client->stream_id = "stream";
 286         client->request.clear();
 287
 288         // Construct the header.
 289         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" +
 290                 streams[client->stream_id].header;
 291
 292         // Switch states.
 293         client->state = Client::SENDING_HEADER;
 294
 295         epoll_event ev;
 296         ev.events = EPOLLOUT | EPOLLRDHUP;
 297         ev.data.fd = client->sock;
 298
 299         if (epoll_ctl(epoll_fd, EPOLL_CTL_MOD, client->sock, &ev) == -1) {
 300                 perror("epoll_ctl(EPOLL_CTL_MOD)");
 301                 exit(1);
 302         }
 303 }
 304
 305 void Server::close_client(Client *client)
 306 {
 307         if (epoll_ctl(epoll_fd, EPOLL_CTL_DEL, client->sock, NULL) == -1) {
 308                 perror("epoll_ctl(EPOLL_CTL_DEL)");
 309                 exit(1);
 310         }
 311
 312         // This client could be sleeping, so we'll need to fix that. (Argh, O(n).)
 313         vector<int>::iterator new_end =
 314                 remove(sleeping_clients.begin(), sleeping_clients.end(), client->sock);
 315         sleeping_clients.erase(new_end, sleeping_clients.end());
 316
 317         // Bye-bye!
 318         close(client->sock);
 319         clients.erase(client->sock);
 320 }
 321
 322 void Server::put_client_to_sleep(Client *client)
 323 {
 324         epoll_event ev;
 325         ev.events = EPOLLRDHUP;
 326         ev.data.fd = client->sock;
 327
 328         if (epoll_ctl(epoll_fd, EPOLL_CTL_MOD, client->sock, &ev) == -1) {
 329                 perror("epoll_ctl(EPOLL_CTL_MOD)");
 330                 exit(1);
 331         }
 332
 333         sleeping_clients.push_back(client->sock);
 334 }
 335
 336 void Server::wake_up_all_clients()
 337 {
 338         for (unsigned i = 0; i < sleeping_clients.size(); ++i) {
 339                 epoll_event ev;
 340                 ev.events = EPOLLOUT | EPOLLRDHUP;
 341                 ev.data.fd = sleeping_clients[i];
 342                 if (epoll_ctl(epoll_fd, EPOLL_CTL_MOD, sleeping_clients[i], &ev) == -1) {
 343                         perror("epoll_ctl(EPOLL_CTL_MOD)");
 344                         exit(1);
 345                 }
 346         }
 347         sleeping_clients.clear();
 348 }