+ switch (client->state) {
+ case Client::READING_REQUEST: {
+read_request_again:
+ // Try to read more of the request.
+ char buf[1024];
+ int ret;
+ do {
+ ret = read(client->sock, buf, sizeof(buf));
+ } while (ret == -1 && errno == EINTR);
+
+ if (ret == -1 && errno == EAGAIN) {
+ // No more data right now. Nothing to do.
+ // This is postcondition #2.
+ return;
+ }
+ if (ret == -1) {
+ log_perror("read");
+ close_client(client);
+ return;
+ }
+ if (ret == 0) {
+ // OK, the socket is closed.
+ close_client(client);
+ return;
+ }
+
+ RequestParseStatus status = wait_for_double_newline(&client->request, buf, ret);
+
+ switch (status) {
+ case RP_OUT_OF_SPACE:
+ log(WARNING, "[%s] Client sent overlong request!", client->remote_addr.c_str());
+ close_client(client);
+ return;
+ case RP_NOT_FINISHED_YET:
+ // OK, we don't have the entire header yet. Fine; we'll get it later.
+ // See if there's more data for us.
+ goto read_request_again;
+ case RP_EXTRA_DATA:
+ log(WARNING, "[%s] Junk data after request!", client->remote_addr.c_str());
+ close_client(client);
+ return;
+ case RP_FINISHED:
+ break;
+ }
+
+ assert(status == RP_FINISHED);
+
+ int error_code = parse_request(client);
+ if (error_code == 200) {
+ construct_header(client);
+ } else {
+ construct_error(client, error_code);
+ }
+
+ // We've changed states, so fall through.
+ assert(client->state == Client::SENDING_ERROR ||
+ client->state == Client::SENDING_HEADER);
+ }
+ case Client::SENDING_ERROR:
+ case Client::SENDING_HEADER: {
+sending_header_or_error_again:
+ int ret;
+ do {
+ ret = write(client->sock,
+ client->header_or_error.data() + client->header_or_error_bytes_sent,
+ client->header_or_error.size() - client->header_or_error_bytes_sent);
+ } while (ret == -1 && errno == EINTR);
+
+ if (ret == -1 && errno == EAGAIN) {
+ // We're out of socket space, so now we're at the “low edge” of epoll's
+ // edge triggering. epoll will tell us when there is more room, so for now,
+ // just return.
+ // This is postcondition #4.
+ return;
+ }
+
+ if (ret == -1) {
+ // Error! Postcondition #1.
+ log_perror("write");
+ close_client(client);
+ return;
+ }
+
+ client->header_or_error_bytes_sent += ret;
+ assert(client->header_or_error_bytes_sent <= client->header_or_error.size());
+
+ if (client->header_or_error_bytes_sent < client->header_or_error.size()) {
+ // We haven't sent all yet. Fine; go another round.
+ goto sending_header_or_error_again;
+ }
+
+ // We're done sending the header or error! Clear it to release some memory.
+ client->header_or_error.clear();
+
+ if (client->state == Client::SENDING_ERROR) {
+ // We're done sending the error, so now close.
+ // This is postcondition #1.
+ close_client(client);
+ return;
+ }
+
+ // Start sending from the first keyframe we get. In other
+ // words, we won't send any of the backlog, but we'll start
+ // sending immediately as we get the next keyframe block.
+ // This is postcondition #3.
+ if (client->stream_pos == size_t(-2)) {
+ client->stream_pos = std::min<size_t>(
+ client->stream->bytes_received - client->stream->backlog_size,
+ 0);
+ client->state = Client::SENDING_DATA;
+ } else {
+ // client->stream_pos should be -1, but it might not be,
+ // if we have clients from an older version.
+ client->stream_pos = client->stream->bytes_received;
+ client->state = Client::WAITING_FOR_KEYFRAME;
+ }
+ client->stream->put_client_to_sleep(client);
+ return;
+ }
+ case Client::WAITING_FOR_KEYFRAME: {
+ Stream *stream = client->stream;
+ if (ssize_t(client->stream_pos) > stream->last_suitable_starting_point) {
+ // We haven't received a keyframe since this stream started waiting,
+ // so keep on waiting for one.
+ // This is postcondition #3.
+ stream->put_client_to_sleep(client);
+ return;
+ }
+ client->stream_pos = stream->last_suitable_starting_point;
+ client->state = Client::SENDING_DATA;
+ // Fall through.
+ }
+ case Client::SENDING_DATA: {
+ skip_lost_data(client);
+ Stream *stream = client->stream;
+
+sending_data_again:
+ size_t bytes_to_send = stream->bytes_received - client->stream_pos;
+ assert(bytes_to_send <= stream->backlog_size);
+ if (bytes_to_send == 0) {
+ return;
+ }
+
+ // See if we need to split across the circular buffer.
+ bool more_data = false;
+ if ((client->stream_pos % stream->backlog_size) + bytes_to_send > stream->backlog_size) {
+ bytes_to_send = stream->backlog_size - (client->stream_pos % stream->backlog_size);
+ more_data = true;
+ }
+
+ ssize_t ret;
+ do {
+ off_t offset = client->stream_pos % stream->backlog_size;
+ ret = sendfile(client->sock, stream->data_fd, &offset, bytes_to_send);
+ } while (ret == -1 && errno == EINTR);
+
+ if (ret == -1 && errno == EAGAIN) {
+ // We're out of socket space, so return; epoll will wake us up
+ // when there is more room.
+ // This is postcondition #4.
+ return;
+ }
+ if (ret == -1) {
+ // Error, close; postcondition #1.
+ log_perror("sendfile");
+ close_client(client);
+ return;
+ }
+ client->stream_pos += ret;
+ client->bytes_sent += ret;
+
+ if (client->stream_pos == stream->bytes_received) {
+ // We don't have any more data for this client, so put it to sleep.
+ // This is postcondition #3.
+ stream->put_client_to_sleep(client);
+ } else if (more_data && size_t(ret) == bytes_to_send) {
+ goto sending_data_again;
+ }
+ break;
+ }
+ default:
+ assert(false);
+ }
+}
+
+// See if there's some data we've lost. Ideally, we should drop to a block boundary,
+// but resync will be the mux's problem.
+void Server::skip_lost_data(Client *client)
+{
+ Stream *stream = client->stream;
+ if (stream == NULL) {
+ return;
+ }
+ size_t bytes_to_send = stream->bytes_received - client->stream_pos;
+ if (bytes_to_send > stream->backlog_size) {
+ size_t bytes_lost = bytes_to_send - stream->backlog_size;
+ client->stream_pos = stream->bytes_received - stream->backlog_size;
+ client->bytes_lost += bytes_lost;
+ ++client->num_loss_events;
+ }
+}
+
+int Server::parse_request(Client *client)
+{
+ vector<string> lines = split_lines(client->request);
+ if (lines.empty()) {
+ return 400; // Bad request (empty).
+ }
+
+ vector<string> request_tokens = split_tokens(lines[0]);
+ if (request_tokens.size() < 2) {
+ return 400; // Bad request (empty).
+ }
+ if (request_tokens[0] != "GET") {
+ return 400; // Should maybe be 405 instead?
+ }
+
+ string url = request_tokens[1];
+ if (url.find("?backlog") == url.size() - 8) {
+ client->stream_pos = -2;
+ url = url.substr(0, url.size() - 8);
+ } else {
+ client->stream_pos = -1;
+ }
+
+ map<string, int>::const_iterator url_map_it = url_map.find(url);
+ if (url_map_it == url_map.end()) {
+ return 404; // Not found.
+ }
+
+ Stream *stream = streams[url_map_it->second];
+ if (stream->http_header.empty()) {
+ return 503; // Service unavailable.
+ }
+
+ client->url = request_tokens[1];
+ client->stream = stream;
+ if (setsockopt(client->sock, SOL_SOCKET, SO_MAX_PACING_RATE, &client->stream->pacing_rate, sizeof(client->stream->pacing_rate)) == -1) {
+ if (client->stream->pacing_rate != ~0U) {
+ log_perror("setsockopt(SO_MAX_PACING_RATE)");
+ }
+ }
+ client->request.clear();
+
+ return 200; // OK!
+}
+
+void Server::construct_header(Client *client)
+{
+ Stream *stream = client->stream;
+ if (stream->encoding == Stream::STREAM_ENCODING_RAW) {
+ client->header_or_error = stream->http_header +
+ "\r\n" +
+ stream->stream_header;
+ } else if (stream->encoding == Stream::STREAM_ENCODING_METACUBE) {
+ client->header_or_error = stream->http_header +
+ "Content-encoding: metacube\r\n" +
+ "\r\n";
+ if (!stream->stream_header.empty()) {
+ metacube2_block_header hdr;
+ memcpy(hdr.sync, METACUBE2_SYNC, sizeof(hdr.sync));
+ hdr.size = htonl(stream->stream_header.size());
+ hdr.flags = htons(METACUBE_FLAGS_HEADER);
+ hdr.csum = htons(metacube2_compute_crc(&hdr));
+ client->header_or_error.append(
+ string(reinterpret_cast<char *>(&hdr), sizeof(hdr)));
+ }
+ client->header_or_error.append(stream->stream_header);
+ } else {
+ assert(false);
+ }
+
+ // Switch states.
+ client->state = Client::SENDING_HEADER;
+
+ epoll_event ev;
+ ev.events = EPOLLOUT | EPOLLET | EPOLLRDHUP;
+ ev.data.u64 = reinterpret_cast<uint64_t>(client);
+
+ if (epoll_ctl(epoll_fd, EPOLL_CTL_MOD, client->sock, &ev) == -1) {
+ log_perror("epoll_ctl(EPOLL_CTL_MOD)");
+ exit(1);
+ }
+}
+
+void Server::construct_error(Client *client, int error_code)
+{
+ char error[256];
+ snprintf(error, 256, "HTTP/1.0 %d Error\r\nContent-type: text/plain\r\n\r\nSomething went wrong. Sorry.\r\n",
+ error_code);
+ client->header_or_error = error;
+
+ // Switch states.
+ client->state = Client::SENDING_ERROR;
+
+ epoll_event ev;
+ ev.events = EPOLLOUT | EPOLLET | EPOLLRDHUP;
+ ev.data.u64 = reinterpret_cast<uint64_t>(client);
+
+ if (epoll_ctl(epoll_fd, EPOLL_CTL_MOD, client->sock, &ev) == -1) {
+ log_perror("epoll_ctl(EPOLL_CTL_MOD)");
+ exit(1);
+ }
+}
+
+template<class T>
+void delete_from(vector<T> *v, T elem)
+{
+ typename vector<T>::iterator new_end = remove(v->begin(), v->end(), elem);
+ v->erase(new_end, v->end());
+}
+
+void Server::close_client(Client *client)
+{
+ if (epoll_ctl(epoll_fd, EPOLL_CTL_DEL, client->sock, NULL) == -1) {
+ log_perror("epoll_ctl(EPOLL_CTL_DEL)");
+ exit(1);
+ }
+
+ // This client could be sleeping, so we'll need to fix that. (Argh, O(n).)
+ if (client->stream != NULL) {
+ delete_from(&client->stream->sleeping_clients, client);
+ delete_from(&client->stream->to_process, client);
+ }
+
+ // Log to access_log.
+ access_log->write(client->get_stats());
+
+ // Bye-bye!
+ safe_close(client->sock);
+
+ clients.erase(client->sock);
+}
+
+void Server::process_queued_data()
+{
+ {
+ MutexLock lock(&queued_clients_mutex);
+
+ for (size_t i = 0; i < queued_add_clients.size(); ++i) {
+ add_client(queued_add_clients[i]);
+ }
+ queued_add_clients.clear();
+ }
+
+ for (size_t i = 0; i < streams.size(); ++i) {
+ streams[i]->process_queued_data();
+ }