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