Add configurable PRAGMA synchronous =

minetest.conf.example

@@ -279,6 +279,8 @@
 #max_objects_per_block = 49
 # Interval of saving important changes in the world
 #server_map_save_interval = 5.3
+# http://www.sqlite.org/pragma.html#pragma_synchronous only numeric values: 0 1 2
+#sqlite_synchronous = 2
 # To reduce lag, block transfers are slowed down when a player is building something.
 # This determines how long they are slowed down after placing or removing a node.
 #full_block_send_enable_min_time_from_building = 2.0

src/database-sqlite3.cpp

@@ -109,6 +109,15 @@ void Database_SQLite3::verifyDatabase() {
 		if(needs_create)
 			createDatabase();
 
+		std::string querystr = std::string("PRAGMA synchronous = ")
+				 + itos(g_settings->getU16("sqlite_synchronous"));
+		d = sqlite3_exec(m_database, querystr.c_str(), NULL, NULL, NULL);
+		if(d != SQLITE_OK) {
+			infostream<<"WARNING: Database pragma set failed: "
+					<<sqlite3_errmsg(m_database)<<std::endl;
+			throw FileNotGoodException("Cannot set pragma");
+		}
+
 		d = sqlite3_prepare(m_database, "SELECT `data` FROM `blocks` WHERE `pos`=? LIMIT 1", -1, &m_database_read, NULL);
 		if(d != SQLITE_OK) {
 			infostream<<"WARNING: SQLite3 database read statment failed to prepare: "<<sqlite3_errmsg(m_database)<<std::endl;

src/defaultsettings.cpp

@@ -191,6 +191,7 @@ void set_default_settings(Settings *settings)
 	settings->setDefault("server_unload_unused_data_timeout", "29");
 	settings->setDefault("max_objects_per_block", "49");
 	settings->setDefault("server_map_save_interval", "5.3");
+	settings->setDefault("sqlite_synchronous", "2");
 	settings->setDefault("full_block_send_enable_min_time_from_building", "2.0");
 	settings->setDefault("dedicated_server_step", "0.1");
 	settings->setDefault("ignore_world_load_errors", "false");