X-Git-Url: https://git.sesse.net/?p=cubemap;a=blobdiff_plain;f=server.cpp;h=72664e33f665eda4bd09e49d22789e546b4ee81f;hp=6fa4991b209f389da7f940aa73ff9462f472b8cd;hb=b757a4a2ce9d24835b52a185134835762af2f50c;hpb=0e96bbf9ee0fbebd5fe3fba4d186c0e0d73c9a32

diff --git a/server.cpp b/server.cpp
index 6fa4991..72664e3 100644
--- a/server.cpp
+++ b/server.cpp
@@ -35,6 +35,23 @@ using namespace std;
 
 extern AccessLogThread *access_log;
 
+namespace {
+
+inline bool is_equal(timespec a, timespec b)
+{
+	return a.tv_sec == b.tv_sec &&
+	       a.tv_nsec == b.tv_nsec;
+}
+
+inline bool is_earlier(timespec a, timespec b)
+{
+	if (a.tv_sec != b.tv_sec)
+		return a.tv_sec < b.tv_sec;
+	return a.tv_nsec < b.tv_nsec;
+}
+
+}  // namespace
+
 Server::Server()
 {
 	pthread_mutex_init(&mutex, NULL);
@@ -90,6 +107,7 @@ void Server::do_work()
 	
 		process_queued_data();
 
+		// Process each client where we have socket activity.
 		for (int i = 0; i < nfds; ++i) {
 			Client *client = reinterpret_cast<Client *>(events[i].data.u64);
 
@@ -101,6 +119,8 @@ void Server::do_work()
 			process_client(client);
 		}
 
+		// Process each client where its stream has new data,
+		// even if there was no socket activity.
 		for (size_t i = 0; i < streams.size(); ++i) {	
 			vector<Client *> to_process;
 			swap(streams[i]->to_process, to_process);
@@ -108,6 +128,49 @@ void Server::do_work()
 				process_client(to_process[i]);
 			}
 		}
+
+		// Finally, go through each client to see if it's timed out
+		// in the READING_REQUEST state. (Seemingly there are clients
+		// that can hold sockets up for days at a time without sending
+		// anything at all.)
+		timespec timeout_time;
+		if (clock_gettime(CLOCK_MONOTONIC_COARSE, &timeout_time) == -1) {
+			log_perror("clock_gettime(CLOCK_MONOTONIC_COARSE)");
+			continue;
+		}
+		timeout_time.tv_sec -= REQUEST_READ_TIMEOUT_SEC;
+		while (!clients_ordered_by_connect_time.empty()) {
+			const pair<timespec, int> &connect_time_and_fd = clients_ordered_by_connect_time.front();
+
+			// See if we have reached the end of clients to process.
+			if (is_earlier(timeout_time, connect_time_and_fd.first)) {
+				break;
+			}
+
+			// If this client doesn't exist anymore, just ignore it
+			// (it was deleted earlier).
+			map<int, Client>::iterator client_it = clients.find(connect_time_and_fd.second);
+			if (client_it == clients.end()) {
+				clients_ordered_by_connect_time.pop();
+				continue;
+			}
+			Client *client = &client_it->second;
+			if (!is_equal(client->connect_time, connect_time_and_fd.first)) {
+				// Another client has taken this fd in the meantime.
+				clients_ordered_by_connect_time.pop();
+				continue;
+			}
+
+			if (client->state != Client::READING_REQUEST) {
+				// Only READING_REQUEST can time out.
+				clients_ordered_by_connect_time.pop();
+				continue;
+			}
+
+			// OK, it timed out.
+			close_client(client);
+			clients_ordered_by_connect_time.pop();
+		}
 	}
 }
 
@@ -154,6 +217,17 @@ void Server::add_client(int sock)
 	assert(ret.second == true);  // Should not already exist.
 	Client *client_ptr = &ret.first->second;
 
+	// Connection timestamps must be nondecreasing. I can't find any guarantee
+	// that even the monotonic clock can't go backwards by a small amount
+	// (think switching between CPUs with non-synchronized TSCs), so if
+	// this actually should happen, we hack around it by fudging
+	// connect_time.
+	if (!clients_ordered_by_connect_time.empty() &&
+	    is_earlier(client_ptr->connect_time, clients_ordered_by_connect_time.back().first)) {
+		client_ptr->connect_time = clients_ordered_by_connect_time.back().first;
+	}
+	clients_ordered_by_connect_time.push(make_pair(client_ptr->connect_time, sock));
+
 	// Start listening on data from this socket.
 	epoll_event ev;
 	ev.events = EPOLLIN | EPOLLET | EPOLLRDHUP;
@@ -182,6 +256,11 @@ void Server::add_client_from_serialized(const ClientProto &client)
 	assert(ret.second == true);  // Should not already exist.
 	Client *client_ptr = &ret.first->second;
 
+	// Connection timestamps must be nondecreasing.
+	assert(clients_ordered_by_connect_time.empty() ||
+	       !is_earlier(client_ptr->connect_time, clients_ordered_by_connect_time.back().first));
+	clients_ordered_by_connect_time.push(make_pair(client_ptr->connect_time, client.sock()));
+
 	// Start listening on data from this socket.
 	epoll_event ev;
 	if (client.state() == Client::READING_REQUEST) {
@@ -207,7 +286,7 @@ void Server::add_client_from_serialized(const ClientProto &client)
 	}
 }
 
-int Server::lookup_stream_by_url(const std::string &url) const
+int Server::lookup_stream_by_url(const string &url) const
 {
 	map<string, int>::const_iterator url_it = url_map.find(url);
 	if (url_it == url_map.end()) {
@@ -238,6 +317,13 @@ void Server::set_backlog_size(int stream_index, size_t new_size)
 	assert(stream_index >= 0 && stream_index < ssize_t(streams.size()));
 	streams[stream_index]->set_backlog_size(new_size);
 }
+
+void Server::set_prebuffering_bytes(int stream_index, size_t new_amount)
+{
+	MutexLock lock(&mutex);
+	assert(stream_index >= 0 && stream_index < ssize_t(streams.size()));
+	streams[stream_index]->prebuffering_bytes = new_amount;
+}
 	
 void Server::set_encoding(int stream_index, Stream::Encoding encoding)
 {
@@ -251,6 +337,17 @@ void Server::set_header(int stream_index, const string &http_header, const strin
 	MutexLock lock(&mutex);
 	assert(stream_index >= 0 && stream_index < ssize_t(streams.size()));
 	streams[stream_index]->http_header = http_header;
+
+	if (stream_header != streams[stream_index]->stream_header) {
+		// We cannot start at any of the older starting points anymore,
+		// since they'd get the wrong header for the stream (not to mention
+		// that a changed header probably means the stream restarted,
+		// which means any client starting on the old one would probably
+		// stop playing properly at the change point). Next block
+		// should be a suitable starting point (if not, something is
+		// pretty strange), so it will fill up again soon enough.
+		streams[stream_index]->suitable_starting_points.clear();
+	}
 	streams[stream_index]->stream_header = stream_header;
 }
 	
@@ -372,43 +469,68 @@ sending_header_or_error_again:
 			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.
+		Stream *stream = client->stream;
 		if (client->stream_pos == size_t(-2)) {
-			client->stream_pos = std::min<size_t>(
-			    client->stream->bytes_received - client->stream->backlog_size,
+			// Start sending from the beginning of the backlog.
+			client->stream_pos = min<size_t>(
+			    stream->bytes_received - 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;
+			goto sending_data;
+		} else if (stream->prebuffering_bytes == 0) {
+			// 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.
+			// Note that this is functionally identical to the next if branch,
+			// except that we save a binary search.
+			client->stream_pos = stream->bytes_received;
 			client->state = Client::WAITING_FOR_KEYFRAME;
+		} else {
+			// We're not going to send anything to the client before we have
+			// N bytes. However, this wait might be boring; we can just as well
+			// use it to send older data if we have it. We use lower_bound()
+			// so that we are conservative and never add extra latency over just
+			// waiting (assuming CBR or nearly so); otherwise, we could want e.g.
+			// 100 kB prebuffer but end up sending a 10 MB GOP.
+			deque<size_t>::const_iterator starting_point_it =
+				lower_bound(stream->suitable_starting_points.begin(),
+					    stream->suitable_starting_points.end(),
+					    stream->bytes_received - stream->prebuffering_bytes);
+			if (starting_point_it == stream->suitable_starting_points.end()) {
+				// None found. Just put us at the end, and then wait for the
+				// first keyframe to appear.
+				client->stream_pos = stream->bytes_received;
+				client->state = Client::WAITING_FOR_KEYFRAME;
+			} else {
+				client->stream_pos = *starting_point_it;
+				client->state = Client::PREBUFFERING;
+				goto prebuffering;
+			}
 		}
-		client->stream->put_client_to_sleep(client);
-		return;
+		// Fall through.
 	}
 	case Client::WAITING_FOR_KEYFRAME: {
 		Stream *stream = client->stream;
-		if (ssize_t(client->stream_pos) > stream->last_suitable_starting_point) {
+		if (stream->suitable_starting_points.empty() ||
+		    client->stream_pos > stream->suitable_starting_points.back()) {
 			// 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->stream_pos = stream->suitable_starting_points.back();
 		client->state = Client::PREBUFFERING;
 		// Fall through.
 	}
 	case Client::PREBUFFERING: {
+prebuffering:
 		Stream *stream = client->stream;
 		size_t bytes_to_send = stream->bytes_received - client->stream_pos;
 		assert(bytes_to_send <= stream->backlog_size);
 		if (bytes_to_send < stream->prebuffering_bytes) {
 			// We don't have enough bytes buffered to start this client yet.
+			// This is postcondition #3.
 			stream->put_client_to_sleep(client);
 			return;
 		}
@@ -416,6 +538,7 @@ sending_header_or_error_again:
 		// Fall through.
 	}
 	case Client::SENDING_DATA: {
+sending_data:
 		skip_lost_data(client);
 		Stream *stream = client->stream;
 
@@ -492,6 +615,18 @@ int Server::parse_request(Client *client)
 		return 400;  // Bad request (empty).
 	}
 
+	// Parse the headers, for logging purposes.
+	// TODO: Case-insensitivity.
+	multimap<string, string> headers = extract_headers(lines, client->remote_addr);
+	multimap<string, string>::const_iterator referer_it = headers.find("Referer");
+	if (referer_it != headers.end()) {
+		client->referer = referer_it->second;
+	}
+	multimap<string, string>::const_iterator user_agent_it = headers.find("User-Agent");
+	if (user_agent_it != headers.end()) {
+		client->user_agent = user_agent_it->second;
+	}
+
 	vector<string> request_tokens = split_tokens(lines[0]);
 	if (request_tokens.size() < 2) {
 		return 400;  // Bad request (empty).
@@ -519,6 +654,7 @@ int Server::parse_request(Client *client)
 	}
 
 	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) {