From 6389a5714d46fc7444678e4fc469e8b04d536cf0 Mon Sep 17 00:00:00 2001
From: Relintai <relintai@protonmail.com>
Date: Wed, 6 Jul 2022 10:11:17 +0200
Subject: [PATCH] Added multi threaded and single threaded Database base
 classes.

---
 modules/database/database.cpp                 |  1 +
 modules/database/database_multi_threaded.cpp  | 60 +++++++++++++++++++
 modules/database/database_multi_threaded.h    | 33 ++++++++++
 modules/database/database_single_threaded.cpp | 36 +++++++++++
 modules/database/database_single_threaded.h   | 33 ++++++++++
 5 files changed, 163 insertions(+)
 create mode 100644 modules/database/database_multi_threaded.cpp
 create mode 100644 modules/database/database_multi_threaded.h
 create mode 100644 modules/database/database_single_threaded.cpp
 create mode 100644 modules/database/database_single_threaded.h

diff --git a/modules/database/database.cpp b/modules/database/database.cpp
index 4c86f73ff..4f1833918 100644
--- a/modules/database/database.cpp
+++ b/modules/database/database.cpp
@@ -20,6 +20,7 @@ Ref<DatabaseConnection> Database::_allocate_connection() {
 	//Ref<DatabaseConnection> dbc;
 	//dbc.instance();
 	//dbc->set_owner(this); //if needed
+	//dbc->connect(_connection_string);
 	//return dbc;
 
 	return Ref<DatabaseConnection>();
diff --git a/modules/database/database_multi_threaded.cpp b/modules/database/database_multi_threaded.cpp
new file mode 100644
index 000000000..4b6c93866
--- /dev/null
+++ b/modules/database/database_multi_threaded.cpp
@@ -0,0 +1,60 @@
+#include "database_multi_threaded.h"
+
+#include "database_connection.h"
+#include "query_builder.h"
+#include "query_result.h"
+#include "table_builder.h"
+
+Ref<DatabaseConnection> DatabaseMultiThreaded::get_connection() {
+	_connection_map_lock.read_lock();
+
+	Thread::ID tid = Thread::get_caller_id();
+	Map<Thread::ID, Ref<DatabaseConnection>>::Element *e;
+	e = _connections.find(tid);
+
+	if (!e) {
+		_connection_map_lock.read_unlock();
+
+		_connection_map_lock.write_lock();
+		Ref<DatabaseConnection> dbc = _allocate_connection();
+		_connections.insert(tid, dbc);
+		_connection_map_lock.write_unlock();
+
+		return dbc;
+	}
+
+	Ref<DatabaseConnection> dbc = e->get();
+	_connection_map_lock.read_unlock();
+
+	return dbc;
+}
+
+Ref<DatabaseConnection> DatabaseMultiThreaded::_allocate_connection() {
+	Ref<DatabaseConnection> dbc;
+	dbc.instance();
+	dbc->set_owner(this);
+	dbc->connect(_connection_string);
+	return dbc;
+}
+
+DatabaseMultiThreaded::DatabaseMultiThreaded() {
+}
+
+DatabaseMultiThreaded::~DatabaseMultiThreaded() {
+	_connection_map_lock.write_lock();
+
+	for (Map<Thread::ID, Ref<DatabaseConnection>>::Element *e = _connections.front(); e; e = e->next()) {
+		Ref<DatabaseConnection> dbc = e->get();
+
+		if (dbc.is_valid()) {
+			dbc->set_owner(nullptr);
+		}
+	}
+
+	_connections.clear();
+
+	_connection_map_lock.write_unlock();
+}
+
+void DatabaseMultiThreaded::_bind_methods() {
+}
diff --git a/modules/database/database_multi_threaded.h b/modules/database/database_multi_threaded.h
new file mode 100644
index 000000000..a7f6690bc
--- /dev/null
+++ b/modules/database/database_multi_threaded.h
@@ -0,0 +1,33 @@
+#ifndef DATABASE_MULTI_THREADED_H
+#define DATABASE_MULTI_THREADED_H
+
+#include "core/map.h"
+#include "core/os/rw_lock.h"
+#include "core/os/thread.h"
+
+#include "database.h"
+
+class QueryBuilder;
+class TableBuilder;
+class QueryResult;
+class DatabaseConnection;
+
+class DatabaseMultiThreaded : public Database {
+	GDCLASS(DatabaseMultiThreaded, Database);
+
+public:
+	Ref<DatabaseConnection> get_connection();
+
+	DatabaseMultiThreaded();
+	~DatabaseMultiThreaded();
+
+protected:
+	Ref<DatabaseConnection> _allocate_connection();
+
+	static void _bind_methods();
+
+	RWLock _connection_map_lock;
+	Map<Thread::ID, Ref<DatabaseConnection>> _connections;
+};
+
+#endif
diff --git a/modules/database/database_single_threaded.cpp b/modules/database/database_single_threaded.cpp
new file mode 100644
index 000000000..e6888af4a
--- /dev/null
+++ b/modules/database/database_single_threaded.cpp
@@ -0,0 +1,36 @@
+#include "database_single_threaded.h"
+
+#include "database_connection.h"
+#include "query_builder.h"
+#include "query_result.h"
+#include "table_builder.h"
+
+Ref<DatabaseConnection> DatabaseSingleThreaded::get_connection() {
+	if (!_connection.is_valid()) {
+		_connection = _allocate_connection();
+	}
+
+	return _connection;
+}
+
+Ref<DatabaseConnection> DatabaseSingleThreaded::_allocate_connection() {
+	Ref<DatabaseConnection> dbc;
+	dbc.instance();
+	dbc->set_owner(this);
+	dbc->connect(_connection_string);
+	return dbc;
+}
+
+DatabaseSingleThreaded::DatabaseSingleThreaded() {
+}
+
+DatabaseSingleThreaded::~DatabaseSingleThreaded() {
+	if (_connection.is_valid()) {
+		_connection->set_owner(nullptr);
+	}
+
+	_connection.unref();
+}
+
+void DatabaseSingleThreaded::_bind_methods() {
+}
diff --git a/modules/database/database_single_threaded.h b/modules/database/database_single_threaded.h
new file mode 100644
index 000000000..5eb757f7d
--- /dev/null
+++ b/modules/database/database_single_threaded.h
@@ -0,0 +1,33 @@
+#ifndef DATABASE_SINGLE_THREADED_H
+#define DATABASE_SINGLE_THREADED_H
+
+#include "core/ustring.h"
+
+#include "database.h"
+
+class QueryBuilder;
+class TableBuilder;
+class QueryResult;
+class DatabaseConnection;
+
+class DatabaseSingleThreaded : public Database {
+	GDCLASS(DatabaseSingleThreaded, Database);
+
+public:
+	String get_connection_string();
+	void set_connection_string(const String &val);
+
+	Ref<DatabaseConnection> get_connection();
+
+	DatabaseSingleThreaded();
+	~DatabaseSingleThreaded();
+
+protected:
+	Ref<DatabaseConnection> _allocate_connection();
+
+	static void _bind_methods();
+
+	Ref<DatabaseConnection> _connection;
+};
+
+#endif