Reset database cursor upon re-use

(cherry picked from commit ca5af2d8907c6415c13ea710e76192b75909c7f1)

DatabaseCursor.cpp

@@ -28,6 +28,9 @@
 DatabaseCursor::DatabaseCursor(CQuery *query, int *timeoutms)
 	: query(query), transaction_lock(false), tries(60), timeoutms(timeoutms),
 	lastErr(SQLITE_OK), _has_error(false), is_shutdown(false)
+#ifdef LOG_READ_QUERIES
+	, db(db)
+#endif
 {
 	query->setupStepping(timeoutms, true);
 
@@ -41,6 +44,22 @@ DatabaseCursor::~DatabaseCursor(void)
 	shutdown();
 }
 
+bool DatabaseCursor::reset()
+{
+	tries = 60;
+	lastErr = SQLITE_OK;
+	_has_error = false;
+	is_shutdown = false;
+	transaction_lock = false;
+
+	query->setupStepping(timeoutms, false);
+
+#ifdef LOG_READ_QUERIES
+	active_query = new ScopedAddActiveQuery(query, db, false);
+#endif
+	return true;
+}
+
 bool DatabaseCursor::next(db_single_result &res)
 {
 	res.clear();

DatabaseCursor.h

@@ -15,6 +15,8 @@ public:
 
 	bool next(db_single_result &res);
 
+	bool reset();
+
 	bool has_error();
 
 	virtual void shutdown();
@@ -31,6 +33,7 @@ private:
 
 #ifdef LOG_READ_QUERIES
 	ScopedAddActiveQuery *active_query;
+	CDatabase* db;
 #endif
 };
 

Interface/DatabaseCursor.h

@@ -10,6 +10,8 @@ public:
 
 	virtual bool has_error()=0;
 
+	virtual bool reset() = 0;
+
 	virtual void shutdown() = 0;
 };
 

Query.cpp

@@ -471,6 +471,11 @@ IDatabaseCursor* CQuery::Cursor(int *timeoutms)
 	{
 		cursor=new DatabaseCursor(this, timeoutms);
 	}
+	else
+	{
+		if (!cursor->reset())
+			return nullptr;
+	}
 
 	return cursor;
 }