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::PREBUFFERING ||
202 (client_ptr->state == Client::SENDING_DATA &&
203 client_ptr->stream_pos == client_ptr->stream->bytes_received)) {
204 client_ptr->stream->put_client_to_sleep(client_ptr);
206 process_client(client_ptr);
210 int Server::lookup_stream_by_url(const std::string &url) const
212 map<string, int>::const_iterator url_it = url_map.find(url);
213 if (url_it == url_map.end()) {
216 return url_it->second;
219 int Server::add_stream(const string &url, size_t backlog_size, size_t prebuffering_bytes, Stream::Encoding encoding)
221 MutexLock lock(&mutex);
222 url_map.insert(make_pair(url, streams.size()));
223 streams.push_back(new Stream(url, backlog_size, prebuffering_bytes, encoding));
224 return streams.size() - 1;
227 int Server::add_stream_from_serialized(const StreamProto &stream, int data_fd)
229 MutexLock lock(&mutex);
230 url_map.insert(make_pair(stream.url(), streams.size()));
231 streams.push_back(new Stream(stream, data_fd));
232 return streams.size() - 1;
235 void Server::set_backlog_size(int stream_index, size_t new_size)
237 MutexLock lock(&mutex);
238 assert(stream_index >= 0 && stream_index < ssize_t(streams.size()));
239 streams[stream_index]->set_backlog_size(new_size);
242 void Server::set_encoding(int stream_index, Stream::Encoding encoding)
244 MutexLock lock(&mutex);
245 assert(stream_index >= 0 && stream_index < ssize_t(streams.size()));
246 streams[stream_index]->encoding = encoding;
249 void Server::set_header(int stream_index, const string &http_header, const string &stream_header)
251 MutexLock lock(&mutex);
252 assert(stream_index >= 0 && stream_index < ssize_t(streams.size()));
253 streams[stream_index]->http_header = http_header;
254 streams[stream_index]->stream_header = stream_header;
257 void Server::set_pacing_rate(int stream_index, uint32_t pacing_rate)
259 MutexLock lock(&mutex);
260 assert(clients.empty());
261 assert(stream_index >= 0 && stream_index < ssize_t(streams.size()));
262 streams[stream_index]->pacing_rate = pacing_rate;
265 void Server::add_data_deferred(int stream_index, const char *data, size_t bytes, StreamStartSuitability suitable_for_stream_start)
267 assert(stream_index >= 0 && stream_index < ssize_t(streams.size()));
268 streams[stream_index]->add_data_deferred(data, bytes, suitable_for_stream_start);
271 // See the .h file for postconditions after this function.
272 void Server::process_client(Client *client)
274 switch (client->state) {
275 case Client::READING_REQUEST: {
277 // Try to read more of the request.
281 ret = read(client->sock, buf, sizeof(buf));
282 } while (ret == -1 && errno == EINTR);
284 if (ret == -1 && errno == EAGAIN) {
285 // No more data right now. Nothing to do.
286 // This is postcondition #2.
291 close_client(client);
295 // OK, the socket is closed.
296 close_client(client);
300 RequestParseStatus status = wait_for_double_newline(&client->request, buf, ret);
303 case RP_OUT_OF_SPACE:
304 log(WARNING, "[%s] Client sent overlong request!", client->remote_addr.c_str());
305 close_client(client);
307 case RP_NOT_FINISHED_YET:
308 // OK, we don't have the entire header yet. Fine; we'll get it later.
309 // See if there's more data for us.
310 goto read_request_again;
312 log(WARNING, "[%s] Junk data after request!", client->remote_addr.c_str());
313 close_client(client);
319 assert(status == RP_FINISHED);
321 int error_code = parse_request(client);
322 if (error_code == 200) {
323 construct_header(client);
325 construct_error(client, error_code);
328 // We've changed states, so fall through.
329 assert(client->state == Client::SENDING_ERROR ||
330 client->state == Client::SENDING_HEADER);
332 case Client::SENDING_ERROR:
333 case Client::SENDING_HEADER: {
334 sending_header_or_error_again:
337 ret = write(client->sock,
338 client->header_or_error.data() + client->header_or_error_bytes_sent,
339 client->header_or_error.size() - client->header_or_error_bytes_sent);
340 } while (ret == -1 && errno == EINTR);
342 if (ret == -1 && errno == EAGAIN) {
343 // We're out of socket space, so now we're at the “low edge” of epoll's
344 // edge triggering. epoll will tell us when there is more room, so for now,
346 // This is postcondition #4.
351 // Error! Postcondition #1.
353 close_client(client);
357 client->header_or_error_bytes_sent += ret;
358 assert(client->header_or_error_bytes_sent <= client->header_or_error.size());
360 if (client->header_or_error_bytes_sent < client->header_or_error.size()) {
361 // We haven't sent all yet. Fine; go another round.
362 goto sending_header_or_error_again;
365 // We're done sending the header or error! Clear it to release some memory.
366 client->header_or_error.clear();
368 if (client->state == Client::SENDING_ERROR) {
369 // We're done sending the error, so now close.
370 // This is postcondition #1.
371 close_client(client);
375 // Start sending from the first keyframe we get. In other
376 // words, we won't send any of the backlog, but we'll start
377 // sending immediately as we get the next keyframe block.
378 // This is postcondition #3.
379 if (client->stream_pos == size_t(-2)) {
380 client->stream_pos = std::min<size_t>(
381 client->stream->bytes_received - client->stream->backlog_size,
383 client->state = Client::SENDING_DATA;
385 // client->stream_pos should be -1, but it might not be,
386 // if we have clients from an older version.
387 client->stream_pos = client->stream->bytes_received;
388 client->state = Client::WAITING_FOR_KEYFRAME;
390 client->stream->put_client_to_sleep(client);
393 case Client::WAITING_FOR_KEYFRAME: {
394 Stream *stream = client->stream;
395 if (ssize_t(client->stream_pos) > stream->last_suitable_starting_point) {
396 // We haven't received a keyframe since this stream started waiting,
397 // so keep on waiting for one.
398 // This is postcondition #3.
399 stream->put_client_to_sleep(client);
402 client->stream_pos = stream->last_suitable_starting_point;
403 client->state = Client::PREBUFFERING;
406 case Client::PREBUFFERING: {
407 Stream *stream = client->stream;
408 size_t bytes_to_send = stream->bytes_received - client->stream_pos;
409 assert(bytes_to_send <= stream->backlog_size);
410 if (bytes_to_send < stream->prebuffering_bytes) {
411 // We don't have enough bytes buffered to start this client yet.
412 stream->put_client_to_sleep(client);
415 client->state = Client::SENDING_DATA;
418 case Client::SENDING_DATA: {
419 skip_lost_data(client);
420 Stream *stream = client->stream;
423 size_t bytes_to_send = stream->bytes_received - client->stream_pos;
424 assert(bytes_to_send <= stream->backlog_size);
425 if (bytes_to_send == 0) {
429 // See if we need to split across the circular buffer.
430 bool more_data = false;
431 if ((client->stream_pos % stream->backlog_size) + bytes_to_send > stream->backlog_size) {
432 bytes_to_send = stream->backlog_size - (client->stream_pos % stream->backlog_size);
438 off_t offset = client->stream_pos % stream->backlog_size;
439 ret = sendfile(client->sock, stream->data_fd, &offset, bytes_to_send);
440 } while (ret == -1 && errno == EINTR);
442 if (ret == -1 && errno == EAGAIN) {
443 // We're out of socket space, so return; epoll will wake us up
444 // when there is more room.
445 // This is postcondition #4.
449 // Error, close; postcondition #1.
450 log_perror("sendfile");
451 close_client(client);
454 client->stream_pos += ret;
455 client->bytes_sent += ret;
457 if (client->stream_pos == stream->bytes_received) {
458 // We don't have any more data for this client, so put it to sleep.
459 // This is postcondition #3.
460 stream->put_client_to_sleep(client);
461 } else if (more_data && size_t(ret) == bytes_to_send) {
462 goto sending_data_again;
471 // See if there's some data we've lost. Ideally, we should drop to a block boundary,
472 // but resync will be the mux's problem.
473 void Server::skip_lost_data(Client *client)
475 Stream *stream = client->stream;
476 if (stream == NULL) {
479 size_t bytes_to_send = stream->bytes_received - client->stream_pos;
480 if (bytes_to_send > stream->backlog_size) {
481 size_t bytes_lost = bytes_to_send - stream->backlog_size;
482 client->stream_pos = stream->bytes_received - stream->backlog_size;
483 client->bytes_lost += bytes_lost;
484 ++client->num_loss_events;
488 int Server::parse_request(Client *client)
490 vector<string> lines = split_lines(client->request);
492 return 400; // Bad request (empty).
495 vector<string> request_tokens = split_tokens(lines[0]);
496 if (request_tokens.size() < 2) {
497 return 400; // Bad request (empty).
499 if (request_tokens[0] != "GET") {
500 return 400; // Should maybe be 405 instead?
503 string url = request_tokens[1];
504 if (url.find("?backlog") == url.size() - 8) {
505 client->stream_pos = -2;
506 url = url.substr(0, url.size() - 8);
508 client->stream_pos = -1;
511 map<string, int>::const_iterator url_map_it = url_map.find(url);
512 if (url_map_it == url_map.end()) {
513 return 404; // Not found.
516 Stream *stream = streams[url_map_it->second];
517 if (stream->http_header.empty()) {
518 return 503; // Service unavailable.
521 client->url = request_tokens[1];
522 client->stream = stream;
523 if (setsockopt(client->sock, SOL_SOCKET, SO_MAX_PACING_RATE, &client->stream->pacing_rate, sizeof(client->stream->pacing_rate)) == -1) {
524 if (client->stream->pacing_rate != ~0U) {
525 log_perror("setsockopt(SO_MAX_PACING_RATE)");
528 client->request.clear();
533 void Server::construct_header(Client *client)
535 Stream *stream = client->stream;
536 if (stream->encoding == Stream::STREAM_ENCODING_RAW) {
537 client->header_or_error = stream->http_header +
539 stream->stream_header;
540 } else if (stream->encoding == Stream::STREAM_ENCODING_METACUBE) {
541 client->header_or_error = stream->http_header +
542 "Content-encoding: metacube\r\n" +
544 if (!stream->stream_header.empty()) {
545 metacube2_block_header hdr;
546 memcpy(hdr.sync, METACUBE2_SYNC, sizeof(hdr.sync));
547 hdr.size = htonl(stream->stream_header.size());
548 hdr.flags = htons(METACUBE_FLAGS_HEADER);
549 hdr.csum = htons(metacube2_compute_crc(&hdr));
550 client->header_or_error.append(
551 string(reinterpret_cast<char *>(&hdr), sizeof(hdr)));
553 client->header_or_error.append(stream->stream_header);
559 client->state = Client::SENDING_HEADER;
562 ev.events = EPOLLOUT | EPOLLET | EPOLLRDHUP;
563 ev.data.u64 = reinterpret_cast<uint64_t>(client);
565 if (epoll_ctl(epoll_fd, EPOLL_CTL_MOD, client->sock, &ev) == -1) {
566 log_perror("epoll_ctl(EPOLL_CTL_MOD)");
571 void Server::construct_error(Client *client, int error_code)
574 snprintf(error, 256, "HTTP/1.0 %d Error\r\nContent-type: text/plain\r\n\r\nSomething went wrong. Sorry.\r\n",
576 client->header_or_error = error;
579 client->state = Client::SENDING_ERROR;
582 ev.events = EPOLLOUT | EPOLLET | EPOLLRDHUP;
583 ev.data.u64 = reinterpret_cast<uint64_t>(client);
585 if (epoll_ctl(epoll_fd, EPOLL_CTL_MOD, client->sock, &ev) == -1) {
586 log_perror("epoll_ctl(EPOLL_CTL_MOD)");
592 void delete_from(vector<T> *v, T elem)
594 typename vector<T>::iterator new_end = remove(v->begin(), v->end(), elem);
595 v->erase(new_end, v->end());
598 void Server::close_client(Client *client)
600 if (epoll_ctl(epoll_fd, EPOLL_CTL_DEL, client->sock, NULL) == -1) {
601 log_perror("epoll_ctl(EPOLL_CTL_DEL)");
605 // This client could be sleeping, so we'll need to fix that. (Argh, O(n).)
606 if (client->stream != NULL) {
607 delete_from(&client->stream->sleeping_clients, client);
608 delete_from(&client->stream->to_process, client);
611 // Log to access_log.
612 access_log->write(client->get_stats());
615 safe_close(client->sock);
617 clients.erase(client->sock);
620 void Server::process_queued_data()
623 MutexLock lock(&queued_clients_mutex);
625 for (size_t i = 0; i < queued_add_clients.size(); ++i) {
626 add_client(queued_add_clients[i]);
628 queued_add_clients.clear();
631 for (size_t i = 0; i < streams.size(); ++i) {
632 streams[i]->process_queued_data();