1 files changed, 75 insertions, 0 deletions
diff --git a/src/crepe/facade/DB.h b/src/crepe/facade/DB.h
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+++ b/src/crepe/facade/DB.h
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+#pragma once
+
+#include <string>
+#include <functional>
+#include <memory>
+
+namespace libdb {
+extern "C" {
+#include <db.h>
+}
+}
+
+namespace crepe {
+
+/**
+ * \brief Berkeley DB facade
+ *
+ * Berkeley DB is a simple key-value database that stores arbitrary data as
+ * both key and value. This facade uses STL strings as keys/values.
+ */
+class DB {
+public:
+	/**
+	 * \param path  The path of the database (created if nonexistant)
+	 */
+	DB(const std::string & path);
+	virtual ~DB() = default;
+
+public:
+	/**
+	 * \brief Get a value from the database, or throw an exception
+	 *
+	 * \param key  The value key
+	 *
+	 * \return The value
+	 *
+	 * \throws Exception if value is not found in DB or other error occurs
+	 */
+	std::string get(const std::string & key);
+	/**
+	 * \brief Set (create or overwrite) a value in the database
+	 *
+	 * \param key  The value key
+	 * \param value  The value to store
+	 *
+	 * \throws Exception if an error occurs
+	 */
+	void set(const std::string & key, const std::string & value);
+	/**
+	 * \brief Check if a key exists in the database
+	 *
+	 * \param key  The value key
+	 *
+	 * \returns True if the key exists, or false if it does not
+	 */
+	bool has(const std::string & key) noexcept;
+
+private:
+	//! RAII wrapper around \c DB struct
+	std::unique_ptr<libdb::DB, std::function<void(libdb::DB *)>> db;
+	//! RAII wrapper around \c DBC struct
+	std::unique_ptr<libdb::DBC, std::function<void(libdb::DBC *)>> cursor;
+
+private:
+	/**
+	 * \brief Convert an STL string to DBT (data base thang)
+	 *
+	 * \param thing  Input data
+	 * \return \c DBT with the same data as input \c thing
+	 */
+	libdb::DBT to_thing(const std::string & thing) const noexcept;
+};
+
+}
+