Merge branch 'master' into decoupling

1 files changed, 114 insertions, 0 deletions

diff --git a/src/crepe/manager/SaveManager.h b/src/crepe/manager/SaveManager.h
new file mode 100644
index 0000000..3d8c852
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+++ b/src/crepe/manager/SaveManager.h
@@ -0,0 +1,114 @@
+#pragma once
+
+#include <memory>
+
+#include "../ValueBroker.h"
+
+namespace crepe {
+
+class DB;
+
+/**
+ * \brief Save data manager
+ *
+ * This class provides access to a simple key-value store that stores
+ * - integers (8-64 bit, signed or unsigned)
+ * - real numbers (float or double)
+ * - string (std::string)
+ *
+ * The underlying database is a key-value store.
+ */
+class SaveManager {
+public:
+	/**
+	 * \brief Get a read/write reference to a value and initialize it if it does not yet exist
+	 *
+	 * \param key  The value key
+	 * \param default_value  Value to initialize \c key with if it does not already exist in the
+	 * database
+	 *
+	 * \return Read/write reference to the value
+	 */
+	template <typename T>
+	ValueBroker<T> get(const std::string & key, const T & default_value);
+
+	/**
+	 * \brief Get a read/write reference to a value
+	 *
+	 * \param key  The value key
+	 *
+	 * \return Read/write reference to the value
+	 *
+	 * \note Attempting to read this value before it is initialized (i.e. set) will result in an
+	 * exception
+	 */
+	template <typename T>
+	ValueBroker<T> get(const std::string & key);
+
+	/**
+	 * \brief Set a value directly
+	 *
+	 * \param key  The value key
+	 * \param value  The value to store
+	 */
+	template <typename T>
+	void set(const std::string & key, const T & value);
+
+	/**
+	 * \brief Check if the save file has a value for this \c key
+	 *
+	 * \param key  The value key
+	 *
+	 * \returns True if the key exists, or false if it does not
+	 */
+	bool has(const std::string & key);
+
+private:
+	SaveManager();
+	virtual ~SaveManager() = default;
+
+private:
+	/**
+	 * \brief Serialize an arbitrary value to STL string
+	 *
+	 * \tparam T  Type of arbitrary value
+	 *
+	 * \returns String representation of value
+	 */
+	template <typename T>
+	std::string serialize(const T &) const noexcept;
+
+	/**
+	 * \brief Deserialize an STL string back to type \c T
+	 *
+	 * \tparam T  Type of value
+	 * \param value  Serialized value
+	 *
+	 * \returns Deserialized value
+	 */
+	template <typename T>
+	T deserialize(const std::string & value) const noexcept;
+
+public:
+	// singleton
+	static SaveManager & get_instance();
+	SaveManager(const SaveManager &) = delete;
+	SaveManager(SaveManager &&) = delete;
+	SaveManager & operator=(const SaveManager &) = delete;
+	SaveManager & operator=(SaveManager &&) = delete;
+
+private:
+	/**
+	 * \brief Create an instance of DB and return its reference
+	 *
+	 * \returns DB instance
+	 *
+	 * This function exists because DB is a facade class, which can't directly be used in the API
+	 * without workarounds
+	 *
+	 * TODO: better solution
+	 */
+	static DB & get_db();
+};
+
+} // namespace crepe