Reuse reset MySQL connections per worker

src/lib/mysql-connector.cpp

@@ -8,7 +8,7 @@
 // actual close at request end, including exception/fatal recovery paths.
 static void mysql_register_request_connection(MySQL* db)
 {
-	if(!context || !db)
+	if(!context || !db || db->worker_persistent)
 		return;
 	auto& connections = context->resources.mysql_connections;
 	if(std::find(connections.begin(), connections.end(), (void*)db) == connections.end())
@@ -57,6 +57,21 @@ bool MySQL::connect(String host, String username, String password)
 	return(true);
 }
 
+bool MySQL::reset_connection()
+{
+	if(!connection || mysql_reset_connection((MYSQL*)connection) != 0)
+		return(false);
+	_preload_next_error_code = 0;
+	affected_rows = 0;
+	field_count = 0;
+	row_count = 0;
+	insert_id = 0;
+	statement_info = "reset";
+	field_info.clear();
+	request_leases = 0;
+	return(true);
+}
+
 String MySQL::escape(String raw, char quote_char)
 {
 	return(mysql_escape(raw, quote_char));

src/lib/mysql-connector.h

@@ -22,6 +22,7 @@ struct MySQL {
 	String statement_info = ""; //
 	bool request_cleanup_delete = false;
 	bool request_pooled = false;
+	bool worker_persistent = false;
 	u32 request_leases = 0;
 	String request_host;
 	String request_username;
@@ -30,6 +31,7 @@ struct MySQL {
 	std::vector<MySQLFieldInfo> field_info;
 
 	bool connect(String host = "localhost", String username = "root", String password = "");
+	bool reset_connection();
 	void disconnect();
 	String error();
 	String escape(String raw, char quote_char = '\'');