VILLASnode/lib/super_node.cpp

/** The super node object holding the state of the application.
 *
 * @author Steffen Vogel <svogel2@eonerc.rwth-aachen.de>
 * @copyright 2014-2022, Institute for Automation of Complex Power Systems, EONERC
 * @license Apache 2.0
 *********************************************************************************/

#include <algorithm>
#include <cstdlib>
#include <cstring>

#include <villas/super_node.hpp>
#include <villas/node.hpp>
#include <villas/path.hpp>
#include <villas/uuid.hpp>
#include <villas/hook_list.hpp>
#include <villas/node/memory.hpp>
#include <villas/config_helper.hpp>
#include <villas/log.hpp>
#include <villas/timing.hpp>
#include <villas/node/exceptions.hpp>
#include <villas/kernel/rt.hpp>
#include <villas/kernel/if.hpp>

#ifdef WITH_NETEM
  #include <villas/kernel/nl.hpp>
#endif

using namespace villas;
using namespace villas::node;

typedef char uuid_string_t[37];

SuperNode::SuperNode() :
	state(State::INITIALIZED),
	idleStop(-1),
#ifdef WITH_API
	api(this),
#endif
#ifdef WITH_WEB
  #ifdef WITH_API
	web(&api),
  #else
	web(),
  #endif
#endif
	priority(0),
	affinity(0),
	hugepages(DEFAULT_NR_HUGEPAGES),
	statsRate(1.0),
	task(CLOCK_REALTIME),
	started(time_now())
{
	int ret;

	char hname[128];
	ret = gethostname(hname, sizeof(hname));
	if (ret)
		throw SystemError("Failed to determine hostname");

	/* Default UUID is derived from hostname */
	uuid::generateFromString(uuid, hname);

#ifdef WITH_NETEM
	kernel::nl::init(); /* Fill link cache */
#endif /* WITH_NETEM */

	logger = logging.get("super_node");
}

void SuperNode::parse(const std::string &u)
{
	config.root = config.load(u);

	parse(config.root);
}

void SuperNode::parse(json_t *root)
{
	int ret;

	assert(state == State::PARSED ||
	       state == State::INITIALIZED ||
	       state == State::CHECKED);

	const char *uuid_str = nullptr;

	json_t *json_nodes = nullptr;
	json_t *json_paths = nullptr;
	json_t *json_logging = nullptr;
	json_t *json_http = nullptr;

	json_error_t err;

	idleStop = 1;

	ret = json_unpack_ex(root, &err, 0, "{ s?: F, s?: o, s?: o, s?: o, s?: o, s?: i, s?: i, s?: i, s?: b, s?: s }",
		"stats", &statsRate,
		"http", &json_http,
		"logging", &json_logging,
		"nodes", &json_nodes,
		"paths", &json_paths,
		"hugepages", &hugepages,
		"affinity", &affinity,
		"priority", &priority,
		"idle_stop", &idleStop,
		"uuid", &uuid_str
	);
	if (ret)
		throw ConfigError(root, err, "node-config", "Unpacking top-level config failed");

	if (uuid_str) {
		ret = uuid_parse(uuid_str, uuid);
		if (ret)
			throw ConfigError(root, "node-config-uuid", "Failed to parse UUID: {}", uuid_str);
	}

#ifdef WITH_WEB
	if (json_http)
		web.parse(json_http);
#endif /* WITH_WEB */

	if (json_logging)
		logging.parse(json_logging);

	/* Parse nodes */
	if (json_nodes) {
		if (!json_is_object(json_nodes))
			throw ConfigError(json_nodes, "node-config-nodes", "Setting 'nodes' must be a group with node name => group mappings.");

		const char *name;
		json_t *json_node;
		json_object_foreach(json_nodes, name, json_node) {
			const char *type;

			ret = Node::isValidName(name);
			if (!ret)
				throw RuntimeError("Invalid name for node: {}", name);

			ret = json_unpack_ex(json_node, &err, 0, "{ s: s }", "type", &type);
			if (ret)
				throw ConfigError(root, err, "node-config-node-type", "Failed to parse type of node '{}'", name);

			json_object_set_new(json_node, "name", json_string(name));

			auto *n = NodeFactory::make(type);
			if (!n)
				throw MemoryAllocationError();

			ret = n->parse(json_node, uuid);
			if (ret) {
				auto config_id = fmt::format("node-config-node-{}", type);

				throw ConfigError(json_node, config_id, "Failed to parse configuration of node '{}'", name);
			}

			json_object_del(json_node, "name");

			nodes.push_back(n);
		}
	}

	/* Parse paths */
	if (json_paths) {
		if (!json_is_array(json_paths))
			logger->warn("Setting 'paths' must be a list of objects");

		size_t i;
		json_t *json_path;
		json_array_foreach(json_paths, i, json_path) {
parse:			auto *p = new Path();
			if (!p)
				throw MemoryAllocationError();

			p->parse(json_path, nodes, uuid);

			paths.push_back(p);

			if (p->isReversed()) {
				/* Only simple paths can be reversed */
				ret = p->isSimple();
				if (!ret)
					throw RuntimeError("Complex paths can not be reversed!");

				/* Parse a second time with in/out reversed */
				json_path = json_copy(json_path);

				json_t *json_in = json_object_get(json_path, "in");
				json_t *json_out = json_object_get(json_path, "out");

				if (json_equal(json_in, json_out))
					throw RuntimeError("Can not reverse path with identical in/out nodes!");

				json_object_set(json_path, "reverse", json_false());
				json_object_set(json_path, "in", json_out);
				json_object_set(json_path, "out", json_in);

				goto parse;
			}
		}
	}

	state = State::PARSED;
}

void SuperNode::check()
{
	int ret;

	assert(state == State::INITIALIZED ||
	       state == State::PARSED ||
	       state == State::CHECKED);

	for (auto *n : nodes) {
		ret = n->check();
		if (ret)
			throw RuntimeError("Invalid configuration for node {}", *n);
	}

	for (auto *p : paths)
		p->check();

	state = State::CHECKED;
}

void SuperNode::prepareNodeTypes()
{
	int ret;

	for (auto *n : nodes) {
		auto *nf = n->getFactory();

		if (nf->getState() == State::STARTED)
			continue;

		ret = nf->start(this);
		if (ret)
			throw RuntimeError("Failed to start node-type: {}", *n->getFactory());
	}
}

void SuperNode::startInterfaces()
{
#ifdef WITH_NETEM
	int ret;

	for (auto *i : interfaces) {
		ret = i->start();
		if (ret)
			throw RuntimeError("Failed to start network interface: {}", i->getName());
	}
#endif /* WITH_NETEM */
}

void SuperNode::startNodes()
{
	int ret;

	for (auto *n : nodes) {
		if (!n->isEnabled())
			continue;

		ret = n->start();
		if (ret)
			throw RuntimeError("Failed to start node: {}", *n);
	}
}

void SuperNode::startPaths()
{
	for (auto *p : paths) {
		if (p->isEnabled())
			p->start();
	}
}

void SuperNode::prepareNodes()
{
	int ret;

	for (auto *n : nodes) {
		if (!n->isEnabled())
			continue;

		ret = n->prepare();
		if (ret)
			throw RuntimeError("Failed to prepare node: {}", *n);
	}
}

void SuperNode::preparePaths()
{
	for (auto *p : paths) {
		if (p->isEnabled())
			p->prepare(nodes);
	}
}

void SuperNode::prepare()
{
	int ret;

	assert(state == State::CHECKED);

	ret = memory::init(hugepages);
	if (ret)
		throw RuntimeError("Failed to initialize memory system");

	kernel::rt::init(priority, affinity);

	prepareNodeTypes();
	prepareNodes();
	preparePaths();

	for (auto *n : nodes) {
		if (n->sources.size() == 0 &&
		    n->destinations.size() == 0) {
			logger->info("Node {} is not used by any path. Disabling...", *n);
			n->setEnabled(false);
		}
	}

	state = State::PREPARED;
}

void SuperNode::start()
{
	assert(state == State::PREPARED);

#ifdef WITH_API
	api.start();
#endif

#ifdef WITH_WEB
	web.start();
#endif

	startInterfaces();
	startNodes();
	startPaths();

	if (statsRate > 0) // A rate <0 will disable the periodic stats
		task.setRate(statsRate);

	Stats::printHeader(Stats::Format::HUMAN);

	state = State::STARTED;
}

void SuperNode::stopPaths()
{
	for (auto *p : paths) {
		if (p->getState() == State::STARTED ||
		    p->getState() == State::PAUSED)
			p->stop();
	}
}

void SuperNode::stopNodes()
{
	int ret;

	for (auto *n : nodes) {
		if (n->getState() == State::STARTED ||
		    n->getState() == State::PAUSED ||
		    n->getState() == State::STOPPING) {
			ret = n->stop();
			if (ret)
				throw RuntimeError("Failed to stop node: {}", *n);
		}
	}
}

void SuperNode::stopNodeTypes()
{
	int ret;

	for (auto *n : nodes) {
		auto *nf = n->getFactory();

		if (nf->getState() != State::STARTED)
			continue;

		ret = nf->stop();
		if (ret)
			throw RuntimeError("Failed to stop node-type: {}", *n->getFactory());
	}
}

void SuperNode::stopInterfaces()
{
#ifdef WITH_NETEM
	int ret;

	for (auto *i : interfaces) {
		ret = i->stop();
		if (ret)
			throw RuntimeError("Failed to stop interface: {}", i->getName());
	}
#endif /* WITH_NETEM */
}

void SuperNode::stop()
{
	stopNodes();
	stopPaths();
	stopNodeTypes();
	stopInterfaces();

#ifdef WITH_API
	api.stop();
#endif

#ifdef WITH_WEB
	web.stop();
#endif

	state = State::STOPPED;
}

void SuperNode::run()
{
	int ret;

	while (state == State::STARTED) {
		task.wait();

		ret = periodic();
		if (ret)
			state = State::STOPPING;
	}
}

SuperNode::~SuperNode()
{
	assert(state == State::INITIALIZED ||
	       state == State::PARSED ||
	       state == State::CHECKED ||
	       state == State::STOPPED ||
	       state == State::PREPARED);

	for (auto *p : paths)
		delete p;

	for (auto *n : nodes)
		delete n;
}

int SuperNode::periodic()
{
	int started = 0;

	for (auto *p : paths) {
		if (p->getState() == State::STARTED) {
			started++;

#ifdef WITH_HOOKS
			p->hooks.periodic();
#endif /* WITH_HOOKS */
		}
	}

	for (auto *n : nodes) {
		if (n->getState() == State::STARTED) {
#ifdef WITH_HOOKS
			n->in.hooks.periodic();
			n->out.hooks.periodic();
#endif /* WITH_HOOKS */
		}
	}

	if (idleStop > 0 && state == State::STARTED && started == 0) {
		logger->info("No more active paths. Stopping super-node");

		return -1;
	}

	return 0;
}

#ifdef WITH_GRAPHVIZ
static
void set_attr(void *ptr, const std::string &key, const std::string &value, bool html = false) {
	Agraph_t *g = agraphof(ptr);

	char *d = (char *) "";
	char *k = (char *) key.c_str();
	char *v = (char *) value.c_str();
	char *vd = html ? agstrdup_html(g, v) : agstrdup(g, v);

	agsafeset(ptr, k, vd, d);
}

graph_t * SuperNode::getGraph()
{
	Agraph_t *g;
	Agnode_t *m;

	g = agopen((char *) "g", Agdirected, 0);

	std::map<Node *, Agnode_t *> nodeMap;

	uuid_string_t uuid_str;

	for (auto *n : nodes) {
		nodeMap[n] = agnode(g, (char *) n->getNameShort().c_str(), 1);

		uuid_unparse(n->getUuid(), uuid_str);

		set_attr(nodeMap[n], "shape", "ellipse");
		set_attr(nodeMap[n], "tooltip", fmt::format("type={}, uuid={}", *n->getFactory(), uuid_str));
		// set_attr(nodeMap[n], "fixedsize", "true");
		// set_attr(nodeMap[n], "width", "0.15");
		// set_attr(nodeMap[n], "height", "0.15");
	}

	unsigned i = 0;
	for (auto *p : paths) {
		auto name = fmt::format("path_{}", i++);

		m = agnode(g, (char *) name.c_str(), 1);

		uuid_unparse(p->uuid, uuid_str);

		set_attr(m, "shape", "box");
		set_attr(m, "tooltip", fmt::format("uuid={}", uuid_str));

		for (auto ps : p->sources)
			agedge(g, nodeMap[ps->getNode()], m, nullptr, 1);

		for (auto pd : p->destinations)
			agedge(g, m, nodeMap[pd->getNode()], nullptr, 1);
	}

	return g;

}
#endif /* WITH_GRAPHVIZ */