Improved config loading to read default options from one file and overrides from another and merge differences properly

include/Core/ConfigFile.h

@@ -2,6 +2,7 @@
 #define ConfigFile_h__
 
 #include <string>
+#include <boost/filesystem.hpp>
 #include <boost/property_tree/ptree.hpp>
 #include <boost/property_tree/ini_parser.hpp>
 
@@ -26,20 +27,23 @@ public:
 	void SaveToDisk();
 
 private:
-	std::string m_Path;
-	boost::property_tree::ptree m_Ptree;
+	boost::filesystem::path m_Path;
+	boost::property_tree::ptree m_PTreeDefaults;
+	boost::property_tree::ptree m_PTreeOverrides;
+	boost::property_tree::ptree m_PTreeMerged;
 };
 
 template <typename T>
 T ConfigFile::GetValue(std::string key, T defaultValue)
 {
-	return m_Ptree.get<T>(key, defaultValue);
+	return m_PTreeMerged.get<T>(key, defaultValue);
 }
 
 template <typename T>
 void ConfigFile::SetValue(std::string key, T value)
 {
-	m_Ptree.put<T>(key, value);
+	m_PTreeOverrides.put<T>(key, value);
+	m_PTreeMerged.put<T>(key, value);
 }
 
 };

src/game/Core/ConfigFile.cpp

@@ -4,14 +4,36 @@
 dd::ConfigFile::ConfigFile(std::string path)
 {
 	m_Path = path;
+
+	boost::filesystem::path defaultFile;
+	defaultFile = m_Path.parent_path() / ("Default" + m_Path.filename().string());
+
+	// Read defaults
+	if (boost::filesystem::exists(defaultFile)) {
 		try {
-		boost::property_tree::ini_parser::read_ini(path, m_Ptree);
+			boost::property_tree::ini_parser::read_ini(defaultFile.string(), m_PTreeDefaults);
 		} catch (boost::property_tree::ptree_error& e) {
-		LOG_ERROR("Failed to load %s", path.c_str());
+			LOG_ERROR("Failed to parse \"%s\":\n%s", defaultFile.string().c_str(), e.what());
 		}
-}
+	} else {
+		LOG_ERROR("Failed to find \"%s\"! Relying on hardcoded default values!", defaultFile.string().c_str());
+	}
+
+	m_PTreeMerged = m_PTreeDefaults;
+
+	// Read overrides
+	if (boost::filesystem::exists(m_Path)) {
+		try {
+			boost::property_tree::ini_parser::read_ini(m_Path.string(), m_PTreeOverrides);
+			for (auto& node : m_PTreeOverrides) {
+				m_PTreeMerged.put_child(node.first, node.second);
+			}
+		} catch (boost::property_tree::ptree_error& e) {
+			LOG_ERROR("Failed to parse \"%s\":\n%s", m_Path.filename().string().c_str(), e.what());
+		}
+	}}
 
 void dd::ConfigFile::SaveToDisk()
 {
-	boost::property_tree::ini_parser::write_ini(m_Path, m_Ptree);
+	boost::property_tree::ini_parser::write_ini(m_Path.string(), m_PTreeOverrides);
 }