[SATELLITE LINKS] PR 1: CSV Parsing module in utils

quisp/utils/OrbitalDataParser.cc

@@ -0,0 +1,59 @@
+/*
+ * OrbitalDataParser.cc
+ *
+ *  Created on: Nov 28, 2023
+ *      Author: paolo
+ *  Quick parser for CSVs, written for csv-based Free-space channels.
+ */
+
+#include "OrbitalDataParser.h"
+
+OrbitalDataParser::OrbitalDataParser(const string filename) {
+  file.open(filename);
+  if (!file.is_open()) throw cRuntimeError("Couldn't find CSV file!");
+  string line;
+  double key = 0;
+  double val = 0;
+  char sep;  // throwaway
+  while (file >> line) {
+    std::istringstream ss(line);
+    ss >> key >> sep >> val;
+    property.insert(std::pair<double, double>(key, val));
+  }
+  return;
+}
+
+double OrbitalDataParser::getPropertyAtTime(const double time) {
+  if (time < getLowestDatapoint()) return getLowestDatavalue();
+  if (time > getHighestDatapoint()) return getHighestDatavalue();
+
+  // These two first lines are there just to provide mathematically sound results.
+  // They should never be used in actual simulation, as they are NOT in any way
+  // guaranteed to be accurate.
+
+  if (time != last_polled_time) {
+    last_polled_time = time;
+    auto u_b = property.upper_bound(time);
+    if (u_b == property.end()) {
+      last_polled_value = (--u_b)->second;
+    } else if (u_b == property.begin()) {
+      last_polled_value = u_b->second;
+    } else {
+      auto l_b = u_b;
+      --l_b;
+      const double delta = (time - l_b->first) / (u_b->first - l_b->first);
+      last_polled_value = delta * u_b->second + (1 - delta) * l_b->second;
+    }
+  }
+  return last_polled_value;
+}
+
+double OrbitalDataParser::getLowestDatapoint() { return property.begin()->first; }
+
+double OrbitalDataParser::getHighestDatapoint() { return property.rbegin()->first; }
+
+double OrbitalDataParser::getLowestDatavalue() { return property.begin()->second; }
+
+double OrbitalDataParser::getHighestDatavalue() { return property.rbegin()->second; }
+
+OrbitalDataParser::~OrbitalDataParser() {}

quisp/utils/OrbitalDataParser.h

@@ -0,0 +1,35 @@
+/*
+ * OrbitalDataParser.h
+ *
+ *  Created on: Nov 28, 2023
+ *      Author: paolo
+ */
+
+#pragma once
+
+#include <omnetpp.h>
+#include <fstream>
+#include <map>
+
+using namespace omnetpp;
+using std::string;
+
+class OrbitalDataParser {
+ public:
+  OrbitalDataParser();
+  OrbitalDataParser(const string filename);
+  virtual ~OrbitalDataParser();
+  double getPropertyAtTime(const double time);
+  double getLowestDatapoint();
+  double getHighestDatapoint();
+  double getLowestDatavalue();
+  double getHighestDatavalue();
+  char* getName;
+
+ private:
+  std::ifstream file;
+  char* name;
+  double last_polled_time = -1;
+  double last_polled_value = -1;
+  std::map<double, double> property;
+};

quisp/utils/OrbitalDataParser_test.cc

@@ -0,0 +1,56 @@
+#include <gtest/gtest.h>
+
+#include <test_utils/TestUtils.h>
+
+#include <fstream>
+
+#include "OrbitalDataParser.h"
+
+#include <cstdio>
+
+using namespace quisp_test;
+using namespace quisp_test::utils;
+using namespace quisp::messages;
+using namespace quisp::modules::SharedResource;
+
+namespace {
+
+class OrbitalDataParserTest : public ::testing::Test {
+ protected:
+  void SetUp() {
+    csv_to_generate.open("channels/test_csv.csv");
+    csv_to_generate << "200,100000\n";
+    csv_to_generate << "300,300000\n";
+    csv_to_generate << "400,200000\n";
+    csv_to_generate.close();
+    csv_parser = new OrbitalDataParser("channels/test_csv.csv");
+  }
+  void TearDown() { std::remove("channels/test_csv.csv"); }
+
+  OrbitalDataParser* csv_parser;
+  std::ofstream csv_to_generate;
+};
+
+TEST_F(OrbitalDataParserTest, lowerBound) {
+  ASSERT_DOUBLE_EQ(csv_parser->getLowestDatapoint(), 200);
+  ASSERT_DOUBLE_EQ(csv_parser->getLowestDatavalue(), 100000);
+}
+
+TEST_F(OrbitalDataParserTest, upperBound) {
+  ASSERT_DOUBLE_EQ(csv_parser->getHighestDatapoint(), 400);
+  ASSERT_DOUBLE_EQ(csv_parser->getHighestDatavalue(), 200000);
+}
+
+TEST_F(OrbitalDataParserTest, lowerThanLB) { ASSERT_DOUBLE_EQ(csv_parser->getPropertyAtTime(100), 100000); }
+
+TEST_F(OrbitalDataParserTest, higherThanUB) { ASSERT_DOUBLE_EQ(csv_parser->getPropertyAtTime(500), 200000); }
+
+TEST_F(OrbitalDataParserTest, normalOperation) {
+  ASSERT_DOUBLE_EQ(csv_parser->getPropertyAtTime(250), 200000);
+  ASSERT_DOUBLE_EQ(csv_parser->getPropertyAtTime(300), 300000);
+  ASSERT_DOUBLE_EQ(csv_parser->getPropertyAtTime(350), 250000);
+  ASSERT_DOUBLE_EQ(csv_parser->getPropertyAtTime(234.5), 169000);
+  ASSERT_DOUBLE_EQ(csv_parser->getPropertyAtTime(287.4), 274800);
+}
+
+}  // namespace