3 #include <netinet/in.h>
10 #include <sys/sendfile.h>
11 #include <sys/socket.h>
12 #include <sys/types.h>
20 #include "accesslog.h"
22 #include "metacube2.h"
23 #include "mutexlock.h"
30 #ifndef SO_MAX_PACING_RATE
31 #define SO_MAX_PACING_RATE 47
36 extern AccessLogThread *access_log;
40 pthread_mutex_init(&mutex, NULL);
41 pthread_mutex_init(&queued_clients_mutex, NULL);
43 epoll_fd = epoll_create(1024); // Size argument is ignored.
45 log_perror("epoll_fd");
52 for (size_t i = 0; i < streams.size(); ++i) {
59 vector<ClientStats> Server::get_client_stats() const
61 vector<ClientStats> ret;
63 MutexLock lock(&mutex);
64 for (map<int, Client>::const_iterator client_it = clients.begin();
65 client_it != clients.end();
67 ret.push_back(client_it->second.get_stats());
72 void Server::do_work()
74 while (!should_stop()) {
75 // Wait until there's activity on at least one of the fds,
76 // or 20 ms (about one frame at 50 fps) has elapsed.
78 // We could in theory wait forever and rely on wakeup()
79 // from add_client_deferred() and add_data_deferred(),
80 // but wakeup is a pretty expensive operation, and the
81 // two threads might end up fighting over a lock, so it's
82 // seemingly (much) more efficient to just have a timeout here.
83 int nfds = epoll_pwait(epoll_fd, events, EPOLL_MAX_EVENTS, EPOLL_TIMEOUT_MS, &sigset_without_usr1_block);
84 if (nfds == -1 && errno != EINTR) {
85 log_perror("epoll_wait");
89 MutexLock lock(&mutex); // We release the mutex between iterations.
91 process_queued_data();
93 for (int i = 0; i < nfds; ++i) {
94 Client *client = reinterpret_cast<Client *>(events[i].data.u64);
96 if (events[i].events & (EPOLLERR | EPOLLRDHUP | EPOLLHUP)) {
101 process_client(client);
104 for (size_t i = 0; i < streams.size(); ++i) {
105 vector<Client *> to_process;
106 swap(streams[i]->to_process, to_process);
107 for (size_t i = 0; i < to_process.size(); ++i) {
108 process_client(to_process[i]);
114 CubemapStateProto Server::serialize()
116 // We don't serialize anything queued, so empty the queues.
117 process_queued_data();
119 // Set all clients in a consistent state before serializing
120 // (ie., they have no remaining lost data). Otherwise, increasing
121 // the backlog could take clients into a newly valid area of the backlog,
122 // sending a stream of zeros instead of skipping the data as it should.
124 // TODO: Do this when clients are added back from serialized state instead;
125 // it would probably be less wasteful.
126 for (map<int, Client>::iterator client_it = clients.begin();
127 client_it != clients.end();
129 skip_lost_data(&client_it->second);
132 CubemapStateProto serialized;
133 for (map<int, Client>::const_iterator client_it = clients.begin();
134 client_it != clients.end();
136 serialized.add_clients()->MergeFrom(client_it->second.serialize());
138 for (size_t i = 0; i < streams.size(); ++i) {
139 serialized.add_streams()->MergeFrom(streams[i]->serialize());
144 void Server::add_client_deferred(int sock)
146 MutexLock lock(&queued_clients_mutex);
147 queued_add_clients.push_back(sock);
150 void Server::add_client(int sock)
152 pair<map<int, Client>::iterator, bool> ret =
153 clients.insert(make_pair(sock, Client(sock)));
154 assert(ret.second == true); // Should not already exist.
155 Client *client_ptr = &ret.first->second;
157 // Start listening on data from this socket.
159 ev.events = EPOLLIN | EPOLLET | EPOLLRDHUP;
160 ev.data.u64 = reinterpret_cast<uint64_t>(client_ptr);
161 if (epoll_ctl(epoll_fd, EPOLL_CTL_ADD, sock, &ev) == -1) {
162 log_perror("epoll_ctl(EPOLL_CTL_ADD)");
166 process_client(client_ptr);
169 void Server::add_client_from_serialized(const ClientProto &client)
171 MutexLock lock(&mutex);
173 int stream_index = lookup_stream_by_url(client.url());
174 if (stream_index == -1) {
175 assert(client.state() != Client::SENDING_DATA);
178 stream = streams[stream_index];
180 pair<map<int, Client>::iterator, bool> ret =
181 clients.insert(make_pair(client.sock(), Client(client, stream)));
182 assert(ret.second == true); // Should not already exist.
183 Client *client_ptr = &ret.first->second;
185 // Start listening on data from this socket.
187 if (client.state() == Client::READING_REQUEST) {
188 ev.events = EPOLLIN | EPOLLET | EPOLLRDHUP;
190 // If we don't have more data for this client, we'll be putting it into
191 // the sleeping array again soon.
192 ev.events = EPOLLOUT | EPOLLET | EPOLLRDHUP;
194 ev.data.u64 = reinterpret_cast<uint64_t>(client_ptr);
195 if (epoll_ctl(epoll_fd, EPOLL_CTL_ADD, client.sock(), &ev) == -1) {
196 log_perror("epoll_ctl(EPOLL_CTL_ADD)");
200 if (client_ptr->state == Client::WAITING_FOR_KEYFRAME ||
201 (client_ptr->state == Client::SENDING_DATA &&
202 client_ptr->stream_pos == client_ptr->stream->bytes_received)) {
203 client_ptr->stream->put_client_to_sleep(client_ptr);
205 process_client(client_ptr);
209 int Server::lookup_stream_by_url(const std::string &url) const
211 map<string, int>::const_iterator url_it = url_map.find(url);
212 if (url_it == url_map.end()) {
215 return url_it->second;
218 int Server::add_stream(const string &url, size_t backlog_size, Stream::Encoding encoding)
220 MutexLock lock(&mutex);
221 url_map.insert(make_pair(url, streams.size()));
222 streams.push_back(new Stream(url, backlog_size, encoding));
223 return streams.size() - 1;
226 int Server::add_stream_from_serialized(const StreamProto &stream, int data_fd)
228 MutexLock lock(&mutex);
229 url_map.insert(make_pair(stream.url(), streams.size()));
230 streams.push_back(new Stream(stream, data_fd));
231 return streams.size() - 1;
234 void Server::set_backlog_size(int stream_index, size_t new_size)
236 MutexLock lock(&mutex);
237 assert(stream_index >= 0 && stream_index < ssize_t(streams.size()));
238 streams[stream_index]->set_backlog_size(new_size);
241 void Server::set_encoding(int stream_index, Stream::Encoding encoding)
243 MutexLock lock(&mutex);
244 assert(stream_index >= 0 && stream_index < ssize_t(streams.size()));
245 streams[stream_index]->encoding = encoding;
248 void Server::set_header(int stream_index, const string &http_header, const string &stream_header)
250 MutexLock lock(&mutex);
251 assert(stream_index >= 0 && stream_index < ssize_t(streams.size()));
252 streams[stream_index]->http_header = http_header;
253 streams[stream_index]->stream_header = stream_header;
256 void Server::set_pacing_rate(int stream_index, uint32_t pacing_rate)
258 MutexLock lock(&mutex);
259 assert(clients.empty());
260 assert(stream_index >= 0 && stream_index < ssize_t(streams.size()));
261 streams[stream_index]->pacing_rate = pacing_rate;
264 void Server::add_data_deferred(int stream_index, const char *data, size_t bytes, StreamStartSuitability suitable_for_stream_start)
266 assert(stream_index >= 0 && stream_index < ssize_t(streams.size()));
267 streams[stream_index]->add_data_deferred(data, bytes, suitable_for_stream_start);
270 // See the .h file for postconditions after this function.
271 void Server::process_client(Client *client)
273 switch (client->state) {
274 case Client::READING_REQUEST: {
276 // Try to read more of the request.
280 ret = read(client->sock, buf, sizeof(buf));
281 } while (ret == -1 && errno == EINTR);
283 if (ret == -1 && errno == EAGAIN) {
284 // No more data right now. Nothing to do.
285 // This is postcondition #2.
290 close_client(client);
294 // OK, the socket is closed.
295 close_client(client);
299 RequestParseStatus status = wait_for_double_newline(&client->request, buf, ret);
302 case RP_OUT_OF_SPACE:
303 log(WARNING, "[%s] Client sent overlong request!", client->remote_addr.c_str());
304 close_client(client);
306 case RP_NOT_FINISHED_YET:
307 // OK, we don't have the entire header yet. Fine; we'll get it later.
308 // See if there's more data for us.
309 goto read_request_again;
311 log(WARNING, "[%s] Junk data after request!", client->remote_addr.c_str());
312 close_client(client);
318 assert(status == RP_FINISHED);
320 int error_code = parse_request(client);
321 if (error_code == 200) {
322 construct_header(client);
324 construct_error(client, error_code);
327 // We've changed states, so fall through.
328 assert(client->state == Client::SENDING_ERROR ||
329 client->state == Client::SENDING_HEADER);
331 case Client::SENDING_ERROR:
332 case Client::SENDING_HEADER: {
333 sending_header_or_error_again:
336 ret = write(client->sock,
337 client->header_or_error.data() + client->header_or_error_bytes_sent,
338 client->header_or_error.size() - client->header_or_error_bytes_sent);
339 } while (ret == -1 && errno == EINTR);
341 if (ret == -1 && errno == EAGAIN) {
342 // We're out of socket space, so now we're at the “low edge” of epoll's
343 // edge triggering. epoll will tell us when there is more room, so for now,
345 // This is postcondition #4.
350 // Error! Postcondition #1.
352 close_client(client);
356 client->header_or_error_bytes_sent += ret;
357 assert(client->header_or_error_bytes_sent <= client->header_or_error.size());
359 if (client->header_or_error_bytes_sent < client->header_or_error.size()) {
360 // We haven't sent all yet. Fine; go another round.
361 goto sending_header_or_error_again;
364 // We're done sending the header or error! Clear it to release some memory.
365 client->header_or_error.clear();
367 if (client->state == Client::SENDING_ERROR) {
368 // We're done sending the error, so now close.
369 // This is postcondition #1.
370 close_client(client);
374 // Start sending from the first keyframe we get. In other
375 // words, we won't send any of the backlog, but we'll start
376 // sending immediately as we get the next keyframe block.
377 // This is postcondition #3.
378 if (client->stream_pos == size_t(-2)) {
379 client->stream_pos = std::min<size_t>(
380 client->stream->bytes_received - client->stream->backlog_size,
382 client->state = Client::SENDING_DATA;
384 // client->stream_pos should be -1, but it might not be,
385 // if we have clients from an older version.
386 client->stream_pos = client->stream->bytes_received;
387 client->state = Client::WAITING_FOR_KEYFRAME;
389 client->stream->put_client_to_sleep(client);
392 case Client::WAITING_FOR_KEYFRAME: {
393 Stream *stream = client->stream;
394 if (ssize_t(client->stream_pos) > stream->last_suitable_starting_point) {
395 // We haven't received a keyframe since this stream started waiting,
396 // so keep on waiting for one.
397 // This is postcondition #3.
398 stream->put_client_to_sleep(client);
401 client->stream_pos = stream->last_suitable_starting_point;
402 client->state = Client::SENDING_DATA;
405 case Client::SENDING_DATA: {
406 skip_lost_data(client);
407 Stream *stream = client->stream;
410 size_t bytes_to_send = stream->bytes_received - client->stream_pos;
411 assert(bytes_to_send <= stream->backlog_size);
412 if (bytes_to_send == 0) {
416 // See if we need to split across the circular buffer.
417 bool more_data = false;
418 if ((client->stream_pos % stream->backlog_size) + bytes_to_send > stream->backlog_size) {
419 bytes_to_send = stream->backlog_size - (client->stream_pos % stream->backlog_size);
425 off_t offset = client->stream_pos % stream->backlog_size;
426 ret = sendfile(client->sock, stream->data_fd, &offset, bytes_to_send);
427 } while (ret == -1 && errno == EINTR);
429 if (ret == -1 && errno == EAGAIN) {
430 // We're out of socket space, so return; epoll will wake us up
431 // when there is more room.
432 // This is postcondition #4.
436 // Error, close; postcondition #1.
437 log_perror("sendfile");
438 close_client(client);
441 client->stream_pos += ret;
442 client->bytes_sent += ret;
444 if (client->stream_pos == stream->bytes_received) {
445 // We don't have any more data for this client, so put it to sleep.
446 // This is postcondition #3.
447 stream->put_client_to_sleep(client);
448 } else if (more_data && size_t(ret) == bytes_to_send) {
449 goto sending_data_again;
458 // See if there's some data we've lost. Ideally, we should drop to a block boundary,
459 // but resync will be the mux's problem.
460 void Server::skip_lost_data(Client *client)
462 Stream *stream = client->stream;
463 if (stream == NULL) {
466 size_t bytes_to_send = stream->bytes_received - client->stream_pos;
467 if (bytes_to_send > stream->backlog_size) {
468 size_t bytes_lost = bytes_to_send - stream->backlog_size;
469 client->stream_pos = stream->bytes_received - stream->backlog_size;
470 client->bytes_lost += bytes_lost;
471 ++client->num_loss_events;
475 int Server::parse_request(Client *client)
477 vector<string> lines = split_lines(client->request);
479 return 400; // Bad request (empty).
482 vector<string> request_tokens = split_tokens(lines[0]);
483 if (request_tokens.size() < 2) {
484 return 400; // Bad request (empty).
486 if (request_tokens[0] != "GET") {
487 return 400; // Should maybe be 405 instead?
490 string url = request_tokens[1];
491 if (url.find("?backlog") == url.size() - 8) {
492 client->stream_pos = -2;
493 url = url.substr(0, url.size() - 8);
495 client->stream_pos = -1;
498 map<string, int>::const_iterator url_map_it = url_map.find(url);
499 if (url_map_it == url_map.end()) {
500 return 404; // Not found.
503 Stream *stream = streams[url_map_it->second];
504 if (stream->http_header.empty()) {
505 return 503; // Service unavailable.
508 client->url = request_tokens[1];
509 client->stream = stream;
510 if (setsockopt(client->sock, SOL_SOCKET, SO_MAX_PACING_RATE, &client->stream->pacing_rate, sizeof(client->stream->pacing_rate)) == -1) {
511 if (client->stream->pacing_rate != ~0U) {
512 log_perror("setsockopt(SO_MAX_PACING_RATE)");
515 client->request.clear();
520 void Server::construct_header(Client *client)
522 Stream *stream = client->stream;
523 if (stream->encoding == Stream::STREAM_ENCODING_RAW) {
524 client->header_or_error = stream->http_header +
526 stream->stream_header;
527 } else if (stream->encoding == Stream::STREAM_ENCODING_METACUBE) {
528 client->header_or_error = stream->http_header +
529 "Content-encoding: metacube\r\n" +
531 if (!stream->stream_header.empty()) {
532 metacube2_block_header hdr;
533 memcpy(hdr.sync, METACUBE2_SYNC, sizeof(hdr.sync));
534 hdr.size = htonl(stream->stream_header.size());
535 hdr.flags = htons(METACUBE_FLAGS_HEADER);
536 hdr.csum = htons(metacube2_compute_crc(&hdr));
537 client->header_or_error.append(
538 string(reinterpret_cast<char *>(&hdr), sizeof(hdr)));
540 client->header_or_error.append(stream->stream_header);
546 client->state = Client::SENDING_HEADER;
549 ev.events = EPOLLOUT | EPOLLET | EPOLLRDHUP;
550 ev.data.u64 = reinterpret_cast<uint64_t>(client);
552 if (epoll_ctl(epoll_fd, EPOLL_CTL_MOD, client->sock, &ev) == -1) {
553 log_perror("epoll_ctl(EPOLL_CTL_MOD)");
558 void Server::construct_error(Client *client, int error_code)
561 snprintf(error, 256, "HTTP/1.0 %d Error\r\nContent-type: text/plain\r\n\r\nSomething went wrong. Sorry.\r\n",
563 client->header_or_error = error;
566 client->state = Client::SENDING_ERROR;
569 ev.events = EPOLLOUT | EPOLLET | EPOLLRDHUP;
570 ev.data.u64 = reinterpret_cast<uint64_t>(client);
572 if (epoll_ctl(epoll_fd, EPOLL_CTL_MOD, client->sock, &ev) == -1) {
573 log_perror("epoll_ctl(EPOLL_CTL_MOD)");
579 void delete_from(vector<T> *v, T elem)
581 typename vector<T>::iterator new_end = remove(v->begin(), v->end(), elem);
582 v->erase(new_end, v->end());
585 void Server::close_client(Client *client)
587 if (epoll_ctl(epoll_fd, EPOLL_CTL_DEL, client->sock, NULL) == -1) {
588 log_perror("epoll_ctl(EPOLL_CTL_DEL)");
592 // This client could be sleeping, so we'll need to fix that. (Argh, O(n).)
593 if (client->stream != NULL) {
594 delete_from(&client->stream->sleeping_clients, client);
595 delete_from(&client->stream->to_process, client);
598 // Log to access_log.
599 access_log->write(client->get_stats());
602 safe_close(client->sock);
604 clients.erase(client->sock);
607 void Server::process_queued_data()
610 MutexLock lock(&queued_clients_mutex);
612 for (size_t i = 0; i < queued_add_clients.size(); ++i) {
613 add_client(queued_add_clients[i]);
615 queued_add_clients.clear();
618 for (size_t i = 0; i < streams.size(); ++i) {
619 streams[i]->process_queued_data();