WIP db facade

10 files changed, 160 insertions, 2 deletions

diff --git a/.gitignore b/.gitignore
index 27d5402..180afb8 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,6 +1,7 @@
 build
 doxygen
 .cache
+*.db
 
 CMakeLists.txt.user
 CMakeCache.txt
@@ -14,3 +15,4 @@ compile_commands.json
 CTestTestfile.cmake
 _deps
 CMakeUserPresets.json
+
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index b60a0cd..de9e990 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -11,6 +11,7 @@ find_package(SDL2 REQUIRED)
 find_package(SDL2_image REQUIRED)
 find_package(SoLoud REQUIRED)
 find_package(GTest REQUIRED)
+find_library(BERKELEY_DB db)
 
 add_library(crepe SHARED)
 add_executable(test_main EXCLUDE_FROM_ALL)
@@ -23,6 +24,7 @@ target_link_libraries(crepe
 	PRIVATE soloud
 	PUBLIC SDL2
 	PUBLIC SDL2_image
+	PUBLIC ${BERKELEY_DB}
 )
 
 add_subdirectory(crepe)
diff --git a/src/crepe/CMakeLists.txt b/src/crepe/CMakeLists.txt
index 97f987a..750a47d 100644
--- a/src/crepe/CMakeLists.txt
+++ b/src/crepe/CMakeLists.txt
@@ -12,8 +12,8 @@ target_sources(crepe PUBLIC
 	CollisionSystem.cpp
 	Collider.cpp
 	SDLContext.cpp
-
 	RenderSystem.cpp
+	DB.cpp
 )
 
 target_sources(crepe PUBLIC FILE_SET HEADERS FILES
@@ -33,6 +33,7 @@ target_sources(crepe PUBLIC FILE_SET HEADERS FILES
 	RenderSystem.h
 	ValueBroker.h
 	ValueBroker.hpp
+	DB.h
 )
 
 add_subdirectory(api)
diff --git a/src/crepe/DB.cpp b/src/crepe/DB.cpp
new file mode 100644
index 0000000..b8448a7
--- /dev/null
+++ b/src/crepe/DB.cpp
@@ -0,0 +1,67 @@
+#include <cstring>
+
+#include "util/log.h"
+
+#include "DB.h"
+
+using namespace std;
+using namespace crepe;
+
+DB::DB(const char * path) {
+	dbg_trace();
+	int ret;
+
+	// init database struct
+	libdb::DB * db;
+	if ((ret = libdb::db_create(&db, NULL, 0)) != 0)
+		throw nullptr; // TODO: exception
+	this->db = { db, [] (libdb::DB * db) { db->close(db, 0); } };
+
+	// load or create database file
+	if ((ret = this->db->open(this->db.get(), NULL, path, NULL, libdb::DB_BTREE, DB_CREATE, 0)) != 0) {
+		throw nullptr;
+	}
+
+	// create cursor
+	libdb::DBC * cursor;
+	if ((ret = this->db->cursor(this->db.get(), NULL, &cursor, 0)) != 0) {
+		throw nullptr;
+	}
+	this->cursor = { cursor, [] (libdb::DBC * cursor) { cursor->close(cursor); } };
+}
+
+
+libdb::DBT DB::to_thing(const string & thing) {
+	libdb::DBT thang;
+	memset(&thang, 0, sizeof(libdb::DBT));
+	thang.data = (void *) thing.data();
+	thang.size = thing.size();
+	return thang;
+}
+
+string DB::get(const string & key) {
+	libdb::DBT db_key = this->to_thing(key);
+	libdb::DBT db_val;
+	memset(&db_val, 0, sizeof(libdb::DBT));
+
+	// int ret = this->cursor->get(this->cursor.get(), NULL, &db_key, &db_val);
+	return "";
+}
+
+void DB::set(const string & key, const string & value) {
+	libdb::DBT db_key = this->to_thing(key);
+	libdb::DBT db_val = this->to_thing(value);
+	int ret = this->db->put(this->db.get(), NULL, &db_key, &db_val, 0);
+	// TODO: check flags
+	// TODO: check ret
+}
+
+bool DB::has(const std::string & key) {
+	try {
+		this->get(key);
+	} catch (...) {
+		return false;
+	}
+	return true;
+}
+
diff --git a/src/crepe/DB.h b/src/crepe/DB.h
new file mode 100644
index 0000000..010ef42
--- /dev/null
+++ b/src/crepe/DB.h
@@ -0,0 +1,34 @@
+#pragma once
+
+#include <string>
+#include <functional>
+#include <memory>
+
+namespace libdb {
+extern "C" {
+#include <db.h>
+}
+}
+
+namespace crepe {
+
+class DB {
+public:
+	DB(const char * path);
+	virtual ~DB() = default;
+
+public:
+	std::string get(const std::string & key);
+	void set(const std::string & key, const std::string & value);
+	bool has(const std::string & key);
+
+private:
+	std::unique_ptr<libdb::DB, std::function<void(libdb::DB *)>> db;
+	std::unique_ptr<libdb::DBC, std::function<void(libdb::DBC *)>> cursor;
+
+private:
+	libdb::DBT to_thing(const std::string & thing);
+};
+
+}
+
diff --git a/src/crepe/api/SaveManager.cpp b/src/crepe/api/SaveManager.cpp
index a05e2c7..83ff0fa 100644
--- a/src/crepe/api/SaveManager.cpp
+++ b/src/crepe/api/SaveManager.cpp
@@ -1,8 +1,19 @@
+#include "../DB.h"
+#include "util/log.h"
+
 #include "SaveManager.h"
 
+using namespace std;
+using namespace crepe;
 using namespace crepe::api;
 
+SaveManager::SaveManager() {
+	dbg_trace();
+	this->db = make_unique<DB>("./save.crepe.db");
+}
+
 SaveManager & SaveManager::get_instance() {
+	dbg_trace();
 	static SaveManager instance;
 	return instance;
 }
diff --git a/src/crepe/api/SaveManager.h b/src/crepe/api/SaveManager.h
index 78cd4ba..110735d 100644
--- a/src/crepe/api/SaveManager.h
+++ b/src/crepe/api/SaveManager.h
@@ -1,7 +1,13 @@
 #pragma once
 
+#include <memory>
+
 #include "../ValueBroker.h"
 
+namespace crepe {
+class DB;
+}
+
 namespace crepe::api {
 
 class SaveManager {
@@ -22,7 +28,7 @@ public:
 	bool has(const char * key);
 
 private:
-	SaveManager() = default;
+	SaveManager();
 	virtual ~SaveManager() = default;
 
 public:
@@ -32,6 +38,9 @@ public:
 	SaveManager(SaveManager &&) = delete;
 	SaveManager & operator = (const SaveManager &) = delete;
 	SaveManager & operator = (SaveManager &&) = delete;
+
+private:
+	std::unique_ptr<DB> db = nullptr;
 };
 
 }
diff --git a/src/example/CMakeLists.txt b/src/example/CMakeLists.txt
index 8158d60..9698c41 100644
--- a/src/example/CMakeLists.txt
+++ b/src/example/CMakeLists.txt
@@ -26,4 +26,5 @@ add_example(particle)
 add_example(physics)
 add_example(savemgr)
 add_example(proxy)
+add_example(db)
 
diff --git a/src/example/db.cpp b/src/example/db.cpp
new file mode 100644
index 0000000..b1ab196
--- /dev/null
+++ b/src/example/db.cpp
@@ -0,0 +1,30 @@
+#include <crepe/DB.h>
+#include <crepe/api/Config.h>
+#include <crepe/util/log.h>
+
+using namespace crepe;
+using namespace std;
+
+// run before main
+static auto _ = [] () {
+	auto & cfg = api::Config::get_instance();
+	cfg.log.level = util::LogLevel::TRACE;
+	return 0;
+}();
+
+int main() {
+	dbg_trace();
+
+	DB db("file.db");
+
+	const char * test_key = "test-key";
+	string test_data = "Hello world!";
+
+	dbg_logf("DB has key = %d", db.has(test_key));
+
+	db.set(test_key, test_data);
+
+	dbg_logf("key = \"%s\"", db.get(test_key).c_str());
+
+	return 0;
+}
diff --git a/src/example/savemgr.cpp b/src/example/savemgr.cpp
index 5c034c4..2c03e3a 100644
--- a/src/example/savemgr.cpp
+++ b/src/example/savemgr.cpp
@@ -14,6 +14,7 @@ using namespace crepe::util;
 
 int main() {
 	const char * key = "mygame.test";
+
 	SaveManager & mgr = SaveManager::get_instance();
 
 	ValueBroker<unsigned int> & prop = mgr.get<unsigned int>(key, 0);