start porting frame streams

src/frame_streams/stream_manager.cpp

@@ -0,0 +1,139 @@
+#include "./stream_manager.hpp"
+
+StreamManager::Connection::Connection(
+	ObjectHandle src_,
+	ObjectHandle sink_,
+	std::unique_ptr<Data>&& data_,
+	std::function<void(Connection&)>&& pump_fn_,
+	std::function<void(Connection&)>&& unsubscribe_fn_,
+	bool on_main_thread_
+) :
+	src(src_),
+	sink(sink_),
+	data(std::move(data_)),
+	pump_fn(std::move(pump_fn_)),
+	unsubscribe_fn(std::move(unsubscribe_fn_)),
+	on_main_thread(on_main_thread_)
+{
+	if (!on_main_thread) {
+		// start thread
+		pump_thread = std::thread([this](void) {
+			while (!stop) {
+				pump_fn(*this);
+				std::this_thread::sleep_for(std::chrono::milliseconds(5));
+			}
+			finished = true;
+		});
+	}
+}
+
+StreamManager::StreamManager(ObjectStore2& os) : _os(os) {}
+
+StreamManager::~StreamManager(void) {
+	// stop all connetions
+	for (const auto& con : _connections) {
+		con->stop = true;
+		if (!con->on_main_thread) {
+			con->pump_thread.join(); // we skip the finished check and wait
+		}
+		con->unsubscribe_fn(*con);
+	}
+}
+
+bool StreamManager::connect(Object src, Object sink, bool threaded) {
+	auto h_src = _os.objectHandle(src);
+	auto h_sink = _os.objectHandle(sink);
+	if (!static_cast<bool>(h_src) || !static_cast<bool>(h_sink)) {
+		// an object does not exist
+		return false;
+	}
+
+	// get src and sink comps
+	if (!h_src.all_of<Components::StreamSource>()) {
+		// src not stream source
+		return false;
+	}
+
+	if (!h_sink.all_of<Components::StreamSink>()) {
+		// sink not stream sink
+		return false;
+	}
+
+	const auto& ssrc = h_src.get<Components::StreamSource>();
+	const auto& ssink = h_sink.get<Components::StreamSink>();
+
+	// compare type
+	if (ssrc.frame_type_name != ssink.frame_type_name) {
+		return false;
+	}
+
+	// always fail in debug mode
+	assert(static_cast<bool>(ssrc.connect_fn));
+	if (!static_cast<bool>(ssrc.connect_fn)) {
+		return false;
+	}
+
+	// use connect fn from src
+	return ssrc.connect_fn(*this, src, sink, threaded);
+}
+
+bool StreamManager::disconnect(Object src, Object sink) {
+	auto res = std::find_if(
+		_connections.cbegin(), _connections.cend(),
+		[&](const auto& a) { return a->src == src && a->sink == sink; }
+	);
+	if (res == _connections.cend()) {
+		// not found
+		return false;
+	}
+
+	// do disconnect
+	(*res)->stop = true;
+
+	return true;
+}
+
+bool StreamManager::disconnectAll(Object o) {
+	bool succ {false};
+	for (const auto& con : _connections) {
+		if (con->src == o || con->sink == o) {
+			con->stop = true;
+			succ = true;
+		}
+	}
+
+	return succ;
+}
+
+// do we need the time delta?
+float StreamManager::tick(float) {
+	// pump all mainthread connections
+	for (auto it = _connections.begin(); it != _connections.end();) {
+		auto& con = **it;
+
+		if (!static_cast<bool>(con.src) || !static_cast<bool>(con.sink)) {
+			// either side disappeard without disconnectAll
+			// TODO: warn/error log
+			con.stop = true;
+		}
+
+		if (con.on_main_thread) {
+			con.pump_fn(con);
+		}
+
+		if (con.stop && (con.finished || con.on_main_thread)) {
+			if (!con.on_main_thread) {
+				assert(con.pump_thread.joinable());
+				con.pump_thread.join();
+			}
+			con.unsubscribe_fn(con);
+			it = _connections.erase(it);
+		} else {
+			it++;
+		}
+	}
+
+	// return min over intervals instead
+	return 2.f; // TODO: 2sec makes mainthread connections unusable
+}
+