api: implement first version of universal data-exchange API

include/villas/api.hpp

@@ -109,7 +109,7 @@ protected:
 	void worker();
 
 public:
-	/** Initalize the API.
+	/** Initialize the API.
 	 *
 	 * Save references to list of paths / nodes for command execution.
 	 */

include/villas/api/requests/universal.hpp

@@ -0,0 +1,49 @@
+/** Universal Data-exchange API request.
+ *
+ * @file
+ * @author Steffen Vogel <svogel2@eonerc.rwth-aachen.de>
+ * @copyright 2014-2022, Institute for Automation of Complex Power Systems, EONERC
+ * @license GNU General Public License (version 3)
+ *
+ * VILLASnode
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *********************************************************************************/
+
+#include <villas/nodes/api.hpp>
+#include <villas/api/requests/node.hpp>
+
+namespace villas {
+namespace node {
+
+/* Forward declarations */
+class Node;
+
+namespace api {
+
+class UniversalRequest : public NodeRequest {
+
+protected:
+	APINode *api_node;
+
+public:
+	using NodeRequest::NodeRequest;
+
+	virtual void
+	prepare();
+};
+
+} /* namespace api */
+} /* namespace node */
+} /* namespace villas */

include/villas/nodes/api.hpp

@@ -0,0 +1,62 @@
+/** Node type: Universal Data-exchange API
+ *
+ * @file
+ * @author Steffen Vogel <svogel2@eonerc.rwth-aachen.de>
+ * @copyright 2014-2022, Institute for Automation of Complex Power Systems, EONERC
+ * @license GNU General Public License (version 3)
+ *
+ * VILLASnode
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *********************************************************************************/
+
+#pragma once
+
+#include <villas/node.hpp>
+#include <pthread.h>
+
+namespace villas {
+namespace node {
+
+/* Forward declarations */
+struct Sample;
+
+class APINode : public Node {
+
+public:
+	APINode(const std::string &name = "");
+
+	struct Direction {
+		Sample *sample;
+		pthread_cond_t cv;
+		pthread_mutex_t mutex;
+	};
+
+	// Accessed by api::universal::SignalRequest
+	Direction read, write;
+
+	virtual
+	int prepare();
+
+protected:
+
+	virtual
+	int _read(struct Sample *smps[], unsigned cnt);
+
+	virtual
+	int _write(struct Sample *smps[], unsigned cnt);
+};
+
+} /* namespace node */
+} /* namespace villas */

include/villas/path.hpp

@@ -129,13 +129,13 @@ public:
 
 		os << CLR_MAG("=>");
 
-		if (p.destinations.size() > 1)
+		if (p.destinations.size() != 1)
 			os << " [";
 
 		for (auto pd : p.destinations)
 			os << " " << pd->getNode()->getNameShort();
 
-		if (p.destinations.size() > 1)
+		if (p.destinations.size() != 1)
 			os << " ]";
 
 		return os;

lib/api/CMakeLists.txt

@@ -28,6 +28,7 @@ set(API_SRC
 
     requests/node.cpp
     requests/path.cpp
+    requests/universal.cpp
 
     requests/status.cpp
     requests/capabiltities.cpp
@@ -43,6 +44,11 @@ set(API_SRC
     requests/paths.cpp
     requests/path_info.cpp
     requests/path_action.cpp
+
+    requests/universal/config.cpp
+    requests/universal/info.cpp
+    requests/universal/signal.cpp
+    requests/universal/signals.cpp
 )
 
 if(WITH_GRAPHVIZ)

lib/api/requests/universal.cpp

@@ -0,0 +1,36 @@
+/** Universal Data-exchange API request
+ *
+ * @file
+ * @author Steffen Vogel <svogel2@eonerc.rwth-aachen.de>
+ * @copyright 2014-2022, Institute for Automation of Complex Power Systems, EONERC
+ * @license GNU General Public License (version 3)
+ *
+ * VILLASnode
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *********************************************************************************/
+
+#include <villas/api/requests/universal.hpp>
+
+using namespace villas::node;
+using namespace villas::node::api;
+
+void UniversalRequest::prepare()
+{
+	NodeRequest::prepare();
+
+	api_node = dynamic_cast<APINode*>(node);
+	if (!api_node)
+		throw BadRequest("Node {} is not an univeral API node!", node->getNameShort());
+}

lib/api/requests/universal/config.cpp

@@ -0,0 +1,57 @@
+/** The Universal Data-exchange API.
+ *
+ * @author Steffen Vogel <svogel2@eonerc.rwth-aachen.de>
+ * @copyright 2014-2022, Institute for Automation of Complex Power Systems, EONERC
+ * @license GNU General Public License (version 3)
+ *
+ * VILLASnode
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *********************************************************************************/
+
+#include <villas/api/requests/universal.hpp>
+#include <villas/api/response.hpp>
+#include <villas/node.hpp>
+
+namespace villas {
+namespace node {
+namespace api {
+namespace universal {
+
+class ConfigRequest : public UniversalRequest {
+public:
+	using UniversalRequest::UniversalRequest;
+
+	virtual Response * execute()
+	{
+		if (method != Session::Method::GET)
+			throw InvalidMethod(this);
+
+		if (body != nullptr)
+			throw BadRequest("This endpoint does not accept any body data");
+
+		return new JsonResponse(session, HTTP_STATUS_OK, node->getConfig());
+	}
+};
+
+/* Register API requests */
+static char n[] = "universal/config";
+static char r[] = "/universal/(" RE_NODE_NAME ")/config";
+static char d[] = "get configuration of universal data-exchange API";
+static RequestPlugin<ConfigRequest, n, r, d> p;
+
+} /* namespace universal */
+} /* namespace api */
+} /* namespace node */
+} /* namespace villas */

lib/api/requests/universal/info.cpp

@@ -0,0 +1,74 @@
+/** The Universal Data-exchange API.
+ *
+ * @author Steffen Vogel <svogel2@eonerc.rwth-aachen.de>
+ * @copyright 2014-2022, Institute for Automation of Complex Power Systems, EONERC
+ * @license GNU General Public License (version 3)
+ *
+ * VILLASnode
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *********************************************************************************/
+
+#include <uuid.h>
+
+#include <villas/api/requests/universal.hpp>
+#include <villas/api/response.hpp>
+#include <villas/node.hpp>
+
+namespace villas {
+namespace node {
+namespace api {
+namespace universal {
+
+class InfoRequest : public UniversalRequest {
+public:
+	using UniversalRequest::UniversalRequest;
+
+	virtual Response * execute()
+	{
+		if (method != Session::Method::GET)
+			throw InvalidMethod(this);
+
+		if (body != nullptr)
+			throw BadRequest("This endpoint does not accept any body data");
+
+		auto uid = node->getUuid();
+
+		char uid_str[UUID_STR_LEN];
+		uuid_unparse(uid, uid_str);
+
+		auto *info = json_pack("{ s: s, s: s, s: { s: s, s: s, s: s } }",
+			"id", node->getNameShort().c_str(),
+			"uuid", uid_str,
+
+			"transport",
+				"type", "villas",
+				"version", PROJECT_VERSION,
+				"build", PROJECT_BUILD_ID
+		);
+
+		return new JsonResponse(session, HTTP_STATUS_OK, info);
+	}
+};
+
+/* Register API requests */
+static char n[] = "universal/info";
+static char r[] = "/universal/(" RE_NODE_NAME ")/info";
+static char d[] = "get infos of universal data-exchange API";
+static RequestPlugin<InfoRequest, n, r, d> p;
+
+} /* namespace universal */
+} /* namespace api */
+} /* namespace node */
+} /* namespace villas */

lib/api/requests/universal/signal.cpp

@@ -0,0 +1,139 @@
+/** The Universal Data-exchange API.
+ *
+ * @author Steffen Vogel <svogel2@eonerc.rwth-aachen.de>
+ * @copyright 2014-2022, Institute for Automation of Complex Power Systems, EONERC
+ * @license GNU General Public License (version 3)
+ *
+ * VILLASnode
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *********************************************************************************/
+
+#include <villas/api/requests/universal.hpp>
+#include <villas/api/response.hpp>
+#include <villas/timing.hpp>
+
+namespace villas {
+namespace node {
+namespace api {
+namespace universal {
+
+class SignalRequest : public UniversalRequest {
+public:
+	using UniversalRequest::UniversalRequest;
+
+	Response * executeGet(const std::string &signalName)
+	{
+		if (body != nullptr)
+			throw BadRequest("This endpoint does not accept any body data");
+
+		pthread_mutex_lock(&api_node->write.mutex);
+
+		auto *smp = api_node->write.sample;
+		if (!smp) {
+			pthread_mutex_unlock(&api_node->write.mutex);
+			throw Error(HTTP_STATUS_NOT_FOUND, "No data available");
+		}
+
+		auto idx = smp->signals->getIndexByName(signalName);
+		if (idx < 0) {
+			pthread_mutex_unlock(&api_node->write.mutex);
+			throw Error(HTTP_STATUS_NOT_FOUND, "Unknown signal id: {}", signalName);
+		}
+
+		auto sig = smp->signals->getByIndex(idx);
+		auto *json_signal = json_pack("{ s: f, s: o }",
+			"timestamp", time_to_double(&smp->ts.origin),
+			"value", smp->data[idx].toJson(sig->type)
+		);
+
+		if (smp->length <= (unsigned) idx)
+			smp->length = idx + 1;
+
+		smp->flags |= (int) SampleFlags::HAS_TS_ORIGIN | (int) SampleFlags::HAS_DATA;
+
+		pthread_mutex_unlock(&api_node->write.mutex);
+
+		logger->info("resp: {}", (void *) json_signal);
+
+		return new JsonResponse(session, HTTP_STATUS_OK, json_signal);
+	}
+
+	Response * executePut(const std::string &signalName)
+	{
+		int ret;
+
+		pthread_mutex_lock(&api_node->read.mutex);
+
+		auto *smp = api_node->read.sample;
+		if (!smp) {
+			pthread_mutex_unlock(&api_node->read.mutex);
+			throw Error(HTTP_STATUS_INTERNAL_SERVER_ERROR, "Not initialized yet");
+		}
+
+		auto idx = smp->signals->getIndexByName(signalName);
+		if (idx < 0) {
+			pthread_mutex_unlock(&api_node->read.mutex);
+			throw BadRequest("Unknown signal id: {}", signalName);
+		}
+
+		auto sig = smp->signals->getByIndex(idx);
+
+		double timestamp = 0;
+		double value = 0;
+
+		json_error_t err;
+		ret = json_unpack_ex(body, &err, 0, "{ s: f, s: f }",
+			"timestamp", &timestamp,
+			"value", &value
+		);
+		if (ret) {
+			pthread_mutex_unlock(&api_node->read.mutex);
+			throw BadRequest("Malformed body: {}", err.text);
+		}
+
+		smp->ts.origin = time_from_double(timestamp);
+		smp->data[idx].f = value;
+
+		pthread_cond_signal(&api_node->read.cv);
+		pthread_mutex_unlock(&api_node->read.mutex);
+
+		return new JsonResponse(session, HTTP_STATUS_OK, json_object());
+	}
+
+	virtual Response * execute()
+	{
+		auto const &signalName = matches[2];
+
+		switch (method) {
+		case Session::Method::GET:
+			return executeGet(signalName);
+		case Session::Method::PUT:
+			return executePut(signalName);
+		default:
+			throw InvalidMethod(this);
+		}
+	}
+};
+
+/* Register API requests */
+static char n[] = "universal/signal";
+static char r[] = "/universal/(" RE_NODE_NAME ")/signal/([a-z0-9_-]+)/state";
+static char d[] = "get or set signal of universal data-exchange API";
+static RequestPlugin<SignalRequest, n, r, d> p;
+
+} /* namespace universal */
+} /* namespace api */
+} /* namespace node */
+} /* namespace villas */

lib/api/requests/universal/signals.cpp

@@ -0,0 +1,81 @@
+/** The Universal Data-exchange API.
+ *
+ * @author Steffen Vogel <svogel2@eonerc.rwth-aachen.de>
+ * @copyright 2014-2022, Institute for Automation of Complex Power Systems, EONERC
+ * @license GNU General Public License (version 3)
+ *
+ * VILLASnode
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *********************************************************************************/
+
+#include <villas/api/requests/universal.hpp>
+#include <villas/api/response.hpp>
+
+namespace villas {
+namespace node {
+namespace api {
+namespace universal {
+
+class SignalsRequest : public UniversalRequest {
+public:
+	using UniversalRequest::UniversalRequest;
+
+	virtual Response * execute()
+	{
+		if (method != Session::Method::GET)
+			throw InvalidMethod(this);
+
+		if (body != nullptr)
+			throw BadRequest("This endpoint does not accept any body data");
+
+		auto *json_sigs = json_array();
+		for (auto const &sig : *node->getOutputSignals()) {
+			auto *json_sig = json_pack("{ s: s, s: s, s: b, s: b, s: o }",
+				"id", fmt::format("out/{}", sig->name).c_str(),
+				"source", node->getNameShort().c_str(),
+				"readable", true,
+				"writable", false,
+				"value", json_null()
+			);
+
+			json_array_append(json_sigs, json_sig);
+		}
+
+		for (auto const &sig : *node->getInputSignals()) {
+			auto *json_sig = json_pack("{ s: s, s: s, s: b, s: b, s: o }",
+				"id", fmt::format("in/{}", sig->name).c_str(),
+				"source", node->getNameShort().c_str(),
+				"readable", false,
+				"writable", true,
+				"value", json_null()
+			);
+
+			json_array_append(json_sigs, json_sig);
+		}
+
+		return new JsonResponse(session, HTTP_STATUS_OK, json_sigs);
+	}
+};
+
+/* Register API requests */
+static char n[] = "universal/signals";
+static char r[] = "/universal/(" RE_NODE_NAME ")/signals";
+static char d[] = "get signals of universal data-exchange API node";
+static RequestPlugin<SignalsRequest, n, r, d> p;
+
+} /* namespace universal */
+} /* namespace api */
+} /* namespace node */
+} /* namespace villas */

lib/nodes/CMakeLists.txt

@@ -24,6 +24,10 @@ set(NODE_SRC
     loopback_internal.cpp
 )
 
+if(WITH_WEB)
+    list(APPEND NODE_SRC api.cpp)
+endif()
+
 # Enable Golang support
 if(WITH_NODE_GO)
     list(APPEND NODE_SRC go.cpp)

lib/nodes/api.cpp

@@ -0,0 +1,93 @@
+/** Node type: Universal Data-exchange API
+ *
+ * @author Steffen Vogel <svogel2@eonerc.rwth-aachen.de>
+ * @copyright 2014-2022, Institute for Automation of Complex Power Systems, EONERC
+ * @license GNU General Public License (version 3)
+ *
+ * VILLASnode
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *********************************************************************************/
+
+#include <vector>
+#include <villas/exceptions.hpp>
+#include <villas/nodes/api.hpp>
+
+using namespace villas;
+using namespace villas::node;
+
+APINode::APINode(const std::string &name) :
+	Node(name)
+{
+	int ret;
+	auto dirs = std::vector{&read, &write};
+
+	for (auto dir : dirs) {
+		ret = pthread_mutex_init(&dir->mutex, nullptr);
+		if (ret)
+			throw RuntimeError("failed to initialize mutex");
+
+		ret = pthread_cond_init(&dir->cv, nullptr);
+		if (ret)
+			throw RuntimeError("failed to initialize mutex");
+	}
+}
+
+int APINode::prepare()
+{
+	auto signals_in = getInputSignals(false);
+
+	read.sample = sample_alloc_mem(signals_in->size());
+	if (!read.sample)
+		throw MemoryAllocationError();
+
+	write.sample = sample_alloc_mem(64);
+	if (!write.sample)
+		throw MemoryAllocationError();
+
+	unsigned j = 0;
+	for (auto sig : *signals_in)
+		read.sample->data[j++] = sig->init;
+
+	read.sample->length = j;
+	read.sample->signals = signals_in;
+
+	return Node::prepare();
+}
+
+int APINode::_read(struct Sample *smps[], unsigned cnt)
+{
+	assert(cnt == 1);
+
+	pthread_cond_wait(&read.cv, &read.mutex);
+
+	sample_copy(smps[0], read.sample);
+
+	return 1;
+}
+
+int APINode::_write(struct Sample *smps[], unsigned cnt)
+{
+	assert(cnt == 1);
+
+	sample_copy(write.sample, smps[0]);
+
+	pthread_cond_signal(&write.cv);
+
+	return 1;
+}
+
+static char n[] = "api";
+static char d[] = "A node providing a HTTP REST interface";
+static NodePlugin<APINode, n , d, (int) NodeFactory::Flags::SUPPORTS_READ | (int) NodeFactory::Flags::SUPPORTS_WRITE, 1> p;