+ Stream *stream = find_stream(stream_id);
+ size_t pos = stream->data_size % BACKLOG_SIZE;
+ stream->data_size += bytes;
+
+ if (pos + bytes > BACKLOG_SIZE) {
+ size_t to_copy = BACKLOG_SIZE - pos;
+ memcpy(stream->data + pos, data, to_copy);
+ data += to_copy;
+ bytes -= to_copy;
+ pos = 0;
+ }
+
+ memcpy(stream->data + pos, data, bytes);
+ stream->wake_up_all_clients();
+}
+
+// See the .h file for postconditions after this function.
+void Server::process_client(Client *client)
+{
+ 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) {
+ 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:
+ fprintf(stderr, "WARNING: fd %d sent overlong request!\n", client->sock);
+ 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:
+ fprintf(stderr, "WARNING: fd %d had junk data after request!\n", client->sock);
+ 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.
+ 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 end. In other words, we won't send any of the backlog,
+ // but we'll start sending immediately as we get data.
+ // This is postcondition #3.
+ client->state = Client::SENDING_DATA;
+ client->bytes_sent = client->stream->data_size;
+ client->stream->put_client_to_sleep(client);
+ return;
+ }
+ case Client::SENDING_DATA: {
+ // 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.
+ Stream *stream = client->stream;
+ size_t bytes_to_send = stream->data_size - client->bytes_sent;
+ if (bytes_to_send == 0) {
+ return;
+ }
+ if (bytes_to_send > BACKLOG_SIZE) {
+ fprintf(stderr, "WARNING: fd %d lost %lld bytes, maybe too slow connection\n",
+ client->sock,
+ (long long int)(bytes_to_send - BACKLOG_SIZE));
+ client->bytes_sent = stream->data_size - BACKLOG_SIZE;
+ bytes_to_send = BACKLOG_SIZE;
+ }
+
+ // See if we need to split across the circular buffer.
+ ssize_t ret;
+ if ((client->bytes_sent % BACKLOG_SIZE) + bytes_to_send > BACKLOG_SIZE) {
+ size_t bytes_first_part = BACKLOG_SIZE - (client->bytes_sent % BACKLOG_SIZE);
+
+ iovec iov[2];
+ iov[0].iov_base = const_cast<char *>(stream->data + (client->bytes_sent % BACKLOG_SIZE));
+ iov[0].iov_len = bytes_first_part;
+
+ iov[1].iov_base = const_cast<char *>(stream->data);
+ iov[1].iov_len = bytes_to_send - bytes_first_part;
+
+ do {
+ ret = writev(client->sock, iov, 2);
+ } while (ret == -1 && errno == EINTR);
+ } else {
+ do {
+ ret = write(client->sock,
+ stream->data + (client->bytes_sent % BACKLOG_SIZE),
+ 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.
+ perror("write/writev");
+ close_client(client);
+ return;
+ }
+ client->bytes_sent += ret;
+
+ if (client->bytes_sent == stream->data_size) {
+ // 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 {
+ // XXX: Do we need to go another round here to explicitly
+ // get the EAGAIN?
+ }
+ break;
+ }
+ default:
+ assert(false);
+ }
+}
+
+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?
+ }
+ if (streams.count(request_tokens[1]) == 0) {
+ return 404; // Not found.
+ }
+
+ client->stream_id = request_tokens[1];
+ client->stream = find_stream(client->stream_id);
+ if (client->stream->mark_pool != NULL) {
+ client->fwmark = client->stream->mark_pool->get_mark();
+ } else {
+ client->fwmark = 0; // No mark.
+ }
+ if (setsockopt(client->sock, SOL_SOCKET, SO_MARK, &client->fwmark, sizeof(client->fwmark)) == -1) {
+ if (client->fwmark != 0) {
+ perror("setsockopt(SO_MARK)");
+ }
+ }
+ client->request.clear();
+
+ return 200; // OK!
+}
+
+void Server::construct_header(Client *client)
+{
+ client->header_or_error = find_stream(client->stream_id)->header;
+
+ // Switch states.
+ client->state = Client::SENDING_HEADER;
+
+ epoll_event ev;
+ ev.events = EPOLLOUT | EPOLLET | EPOLLRDHUP;
+ ev.data.u64 = 0; // Keep Valgrind happy.
+ ev.data.fd = client->sock;
+
+ if (epoll_ctl(epoll_fd, EPOLL_CTL_MOD, client->sock, &ev) == -1) {
+ 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 = 0; // Keep Valgrind happy.
+ ev.data.fd = client->sock;
+
+ if (epoll_ctl(epoll_fd, EPOLL_CTL_MOD, client->sock, &ev) == -1) {
+ 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) {
+ 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);
+ if (client->stream->mark_pool != NULL) {
+ int fwmark = client->fwmark;
+ client->stream->mark_pool->release_mark(fwmark);
+ }
+ }
+
+ // Bye-bye!
+ int ret;
+ do {
+ ret = close(client->sock);
+ } while (ret == -1 && errno == EINTR);
+
+ if (ret == -1) {
+ perror("close");
+ }
+
+ clients.erase(client->sock);
+}
+
+Stream *Server::find_stream(const string &stream_id)
+{
+ map<string, Stream *>::iterator it = streams.find(stream_id);
+ assert(it != streams.end());
+ return it->second;
+}
+
+void Server::process_queued_data()
+{
+ MutexLock lock(&queued_data_mutex);
+
+ for (size_t i = 0; i < queued_add_clients.size(); ++i) {
+ add_client(queued_add_clients[i]);
+ }
+ queued_add_clients.clear();
+
+ for (map<string, string>::iterator queued_it = queued_data.begin();
+ queued_it != queued_data.end();
+ ++queued_it) {
+ add_data(queued_it->first, queued_it->second.data(), queued_it->second.size());
+ }
+ queued_data.clear();