add round hook

lib/hooks/CMakeLists.txt

@@ -39,6 +39,7 @@ set(HOOK_SRC
     print.cpp
     restart.cpp
     rms.cpp
+    round.cpp
     scale.cpp
     shift_seq.cpp
     shift_ts.cpp

lib/hooks/round.cpp

@@ -0,0 +1,91 @@
+/** Scale hook.
+ *
+ * @author Manuel Pitz <manuel.pitz@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 <cstring>
+
+#include <villas/hook.hpp>
+#include <villas/sample.hpp>
+
+namespace villas {
+namespace node {
+
+class RoundHook : public MultiSignalHook {
+
+protected:
+	unsigned precision;
+
+public:
+	RoundHook(Path *p, Node *n, int fl, int prio, bool en = true) :
+		MultiSignalHook(p, n, fl, prio, en),
+		precision(1)
+	{ }
+
+	virtual void parse(json_t *json)
+	{
+		int ret;
+		json_error_t err;
+
+		assert(state != State::STARTED);
+
+		MultiSignalHook::parse(json);
+
+		ret = json_unpack_ex(json, &err, 0, "{ s?: i}",
+			"precision", &precision
+		);
+		if (ret)
+			throw ConfigError(json, err, "node-config-hook-round");
+
+		state = State::PARSED;
+	}
+
+	virtual Hook::Reason process(struct Sample *smp)
+	{
+		for (auto index : signalIndices) {
+			assert(index < smp->length);
+			assert(state == State::STARTED);
+
+			switch (sample_format(smp, index)) {
+				case SignalType::FLOAT:
+					smp->data[index].f = round(smp->data[index].f * pow(10, precision)) / pow(10, precision);
+					break;
+
+				case SignalType::COMPLEX:
+					smp->data[index].z = std::complex<float>(
+						round(smp->data[index].z.real() * pow(10, precision)) / pow(10, precision),
+						round(smp->data[index].z.imag() * pow(10, precision)) / pow(10, precision)
+					);
+					break;
+				default: { }
+			}
+		}
+
+		return Reason::OK;
+	}
+};
+
+/* Register hook */
+static char n[] = "round";
+static char d[] = "Round signals to a set number of digits";
+static HookPlugin<RoundHook, n, d, (int) Hook::Flags::PATH | (int) Hook::Flags::NODE_READ | (int) Hook::Flags::NODE_WRITE> p;
+
+} /* namespace node */
+} /* namespace villas */