From c0049fc7b6fdcf7bed3e2e95b99f429b841f8ce5 Mon Sep 17 00:00:00 2001
From: Albert S <mail@quitesimple.org>
Date: Sat, 29 Jul 2023 10:00:22 +0200
Subject: [PATCH] sqlite: Use per-thread connections

---
 database/database.h           |  2 +-
 database/sessiondaosqlite.cpp |  2 +-
 database/sqlite.cpp           | 53 ++++++++++++++++++++++-------------
 database/sqlite.h             |  8 ++++--
 database/sqlitedao.h          | 10 +++----
 5 files changed, 45 insertions(+), 30 deletions(-)

diff --git a/database/database.h b/database/database.h
index 3e7ee5e..380ba17 100644
--- a/database/database.h
+++ b/database/database.h
@@ -13,7 +13,7 @@
 #include "permissionsdao.h"
 class Database
 {
-  private:
+  protected:
 	std::string connnectionstring;
 
   public:
diff --git a/database/sessiondaosqlite.cpp b/database/sessiondaosqlite.cpp
index fde0e65..b7f5bfc 100755
--- a/database/sessiondaosqlite.cpp
+++ b/database/sessiondaosqlite.cpp
@@ -54,7 +54,7 @@ void SessionDaoSqlite::fillSession(int userid, Session &sess)
 {
 	if(userid > -1)
 	{
-		UserDaoSqlite userDao{this->db};
+		UserDaoSqlite userDao{*this->db};
 		auto u = userDao.find(userid);
 		if(u)
 		{
diff --git a/database/sqlite.cpp b/database/sqlite.cpp
index 1b01321..cabcd08 100644
--- a/database/sqlite.cpp
+++ b/database/sqlite.cpp
@@ -18,23 +18,43 @@ LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 SOFTWARE.
 */
+#include <atomic>
 #include "sqlite.h"
-#include "../logger.h"
 #include "pagedaosqlite.h"
 #include "revisiondaosqlite.h"
 #include "sessiondaosqlite.h"
+#include "sqlite_modern_cpp.h"
 #include "userdaosqlite.h"
 #include "categorydaosqlite.h"
-#include "exceptions.h"
 #include "permissionsdaosqlite.h"
 
+thread_local sqlite::database *Sqlite::db = nullptr;
+
+std::atomic<int> instances = 0;
 Sqlite::Sqlite(std::string path) : Database(path)
 {
-	this->db = std::make_shared<sqlite::database>(path);
-
-	*db << "PRAGMA journal_mode=WAL;";
+	instances++;
+	if(instances.load() > 1)
+	{
+		std::cerr << "temporal (yeah, right) HACK... only one instance allowed" << std::endl;
+		abort();
+	}
 }
 
+std::mutex dbmutex;
+sqlite::database &Sqlite::database() const
+{
+	if(Sqlite::db == nullptr)
+	{
+		sqlite::sqlite_config config;
+		config.flags = config.flags | sqlite::OpenFlags::FULLMUTEX;
+		std::lock_guard<std::mutex> dbguard(dbmutex);
+		Sqlite::db = new sqlite::database(this->connnectionstring, config);
+		*Sqlite::db << "PRAGMA journal_mode=WAL;";
+		*Sqlite::db << "PRAGMA busy_timeout=10000;";
+	}
+	return *Sqlite::db;
+}
 std::unique_ptr<RevisionDao> Sqlite::createRevisionDao() const
 {
 	return create<RevisionDaoSqlite>();
@@ -67,27 +87,20 @@ std::unique_ptr<PermissionsDao> Sqlite::createPermissionsDao() const
 
 void Sqlite::beginTransaction()
 {
-	if(!inTransaction)
-	{
-		*db << "begin;";
-		inTransaction = true;
-	}
+	*db << "begin;";
 }
 
 void Sqlite::rollbackTransaction()
 {
-	if(inTransaction)
-	{
-		*db << "rollback;";
-		inTransaction = false;
-	}
+	*db << "rollback;";
 }
 
 void Sqlite::commitTransaction()
 {
-	if(inTransaction)
-	{
-		*db << "commit;";
-		inTransaction = false;
-	}
+	*db << "commit;";
+}
+
+Sqlite::~Sqlite()
+{
+	delete this->db;
 }
diff --git a/database/sqlite.h b/database/sqlite.h
index 6411daf..dda7fae 100644
--- a/database/sqlite.h
+++ b/database/sqlite.h
@@ -8,14 +8,15 @@
 class Sqlite : public Database
 {
   private:
-	bool inTransaction = false;
-	std::shared_ptr<sqlite::database> db;
+	static thread_local sqlite::database *db;
 
 	template <class T> std::unique_ptr<T> create() const
 	{
-		return std::make_unique<T>(db);
+		return std::make_unique<T>(database());
 	}
 
+	sqlite::database &database() const;
+
   public:
 	Sqlite(std::string path);
 	std::unique_ptr<PageDao> createPageDao() const;
@@ -27,6 +28,7 @@ class Sqlite : public Database
 	void beginTransaction();
 	void commitTransaction();
 	void rollbackTransaction();
+	virtual ~Sqlite();
 };
 
 #endif // SQLITE_H
diff --git a/database/sqlitedao.h b/database/sqlitedao.h
index 535e2f0..347ce93 100644
--- a/database/sqlitedao.h
+++ b/database/sqlitedao.h
@@ -12,20 +12,20 @@
 class SqliteDao
 {
   protected:
-	std::shared_ptr<sqlite::database> db;
+	sqlite::database *db = nullptr;
 
   public:
 	SqliteDao()
 	{
 	}
 
-	SqliteDao(std::shared_ptr<sqlite::database> db)
+	SqliteDao(sqlite::database &db)
 	{
-		this->db = db;
+		this->db = &db;
 	}
-	void setDb(std::shared_ptr<sqlite::database> db)
+	void setDb(sqlite::database &db)
 	{
-		this->db = db;
+		this->db = &db;
 	}
 
 	inline void throwFrom(const sqlite::sqlite_exception &e) const