From 17de42a947872aebd6cbaa6aa472aa04f32d0e24 Mon Sep 17 00:00:00 2001
From: Zwelf <zwelf@strct.cc>
Date: Sun, 12 Jul 2020 12:21:41 +0200
Subject: [PATCH] Implement locking in SQLite

---
 src/engine/server/databases/sqlite.cpp | 10 ++++++++++
 src/engine/server/databases/sqlite.h   |  1 +
 2 files changed, 11 insertions(+)

diff --git a/src/engine/server/databases/sqlite.cpp b/src/engine/server/databases/sqlite.cpp
index f3cd29d4d..c15227980 100644
--- a/src/engine/server/databases/sqlite.cpp
+++ b/src/engine/server/databases/sqlite.cpp
@@ -11,6 +11,7 @@ CSqliteConnection::CSqliteConnection(const char *pFilename, bool Setup) :
 	m_pDb(nullptr),
 	m_pStmt(nullptr),
 	m_Done(true),
+	m_Locked(false),
 	m_InUse(false)
 {
 	str_copy(m_aFilename, pFilename, sizeof(m_aFilename));
@@ -67,6 +68,7 @@ IDbConnection::Status CSqliteConnection::Connect()
 			return Status::ERROR;
 		m_Setup = false;
 	}
+	m_Locked = false;
 	return Status::SUCCESS;
 }
 
@@ -80,10 +82,18 @@ void CSqliteConnection::Disconnect()
 
 void CSqliteConnection::Lock(const char *pTable)
 {
+	// locks the whole database read/write
+	Execute("BEGIN EXCLUSIVE TRANSACTION;");
+	m_Locked = true;
 }
 
 void CSqliteConnection::Unlock()
 {
+	if(m_Locked)
+	{
+		Execute("COMMIT TRANSACTION;");
+		m_Locked = false;
+	}
 }
 
 void CSqliteConnection::PrepareStatement(const char *pStmt)
diff --git a/src/engine/server/databases/sqlite.h b/src/engine/server/databases/sqlite.h
index 8e45c0ded..f68c05185 100644
--- a/src/engine/server/databases/sqlite.h
+++ b/src/engine/server/databases/sqlite.h
@@ -45,6 +45,7 @@ private:
 	sqlite3 *m_pDb;
 	sqlite3_stmt *m_pStmt;
 	bool m_Done; // no more rows available for Step
+	bool m_Locked;
 	// returns true, if the query succeded
 	bool Execute(const char *pQuery);