Method rollback

tx.go:323–343

rollback needs to reload the free pages from disk in case some system error happens like fsync error.

()

// rollback needs to reload the free pages from disk in case some system error happens like fsync error.
func (tx *Tx) rollback() {
	if tx.db == nil {
		return
	}
	if tx.writable {
		tx.db.freelist.Rollback(tx.meta.Txid())
		// When mmap fails, the `data`, `dataref` and `datasz` may be reset to
		// zero values, and there is no way to reload free page IDs in this case.
		if tx.db.data != nil {
			if !tx.db.hasSyncedFreelist() {
				// Reconstruct free page list by scanning the DB to get the whole free page list.
				// Note: scanning the whole db is heavy if your db size is large in NoSyncFreeList mode.
				tx.db.freelist.NoSyncReload(tx.db.freepages())
			} else {
				// Read free page list from freelist page.
				tx.db.freelist.Reload(tx.db.page(tx.db.meta().Freelist()))
			}
		}
	}
	tx.close()
}

func (tx *Tx) close() {
	if tx.db == nil {