First server executable

helpers.cpp

@@ -0,0 +1,101 @@
+#include "helpers.h"
+
+#include <fstream>
+
+using nlohmann::json;
+
+using std::endl;
+using std::ifstream;
+using std::istream;
+using std::ostream;
+using std::string;
+
+bool read_config_json(json& cfg, const string& filename, ostream* log)
+{
+	ifstream cfg_file(filename);
+
+	if (!cfg_file.is_open())
+	{
+		if (nullptr != log)
+		{
+			*log << "Could not open config file" << endl;
+		}
+		return false;
+	}
+
+	return read_config_json(cfg, cfg_file, log);
+}
+
+bool read_config_json(json& cfg, istream& in, ostream* log)
+{
+	// Parse with comments
+	try
+	{
+		cfg = json::parse(in, nullptr, true, true);
+	}
+	catch (const std::exception &e)
+	{
+		if (nullptr != log)
+		{
+			*log << e.what() << endl;
+		}
+		return false;
+	}
+
+	return true;
+}
+
+bool json_extract(const json& j, const string& key, string& out)
+{
+	bool result = false;
+
+	if (j.contains(key) && j[key].is_string())
+	{
+		out = j[key];
+		result = true;
+	}
+
+	return result;
+}
+
+bool json_extract(const json& j, const string& key, int& out)
+{
+	bool result = false;
+
+	if (j.contains(key) && j[key].is_number_integer())
+	{
+		out = j[key];
+		result = true;
+	}
+
+	return result;
+}
+
+bool json_extract(const json& j, const string& key, bool& out)
+{
+	bool result = false;
+
+	if (j.contains(key) && j[key].is_boolean())
+	{
+		out = j[key];
+		result = true;
+	}
+
+	return result;
+}
+
+bool json_extract(const json& j, const string& key, uint16_t& out)
+{
+	bool result = false;
+
+	if (j.contains(key) && j[key].is_number_integer())
+	{
+		if ((j[key] >= 0) && (j[key] <= UINT16_MAX))
+		{
+			out = j[key];
+			result = true;
+		}
+	}
+
+	return result;
+}