// open a write ahead log file w, err := Open("testlog") // write some records pos, err = w.Write("first record") pos, err = w.Write("second record") pos, err = w.Write("third record") // read all records from head r, err = w.NewReader(0) for { pos, data, err = r.Next() if pos == -1{ break } } // truncate the log from position before 100 err = w.TruncateBefore(100) // truncate the log from position after 200 err = w.TruncateAfter(200) // backup name, err = w.Backup() // recover the write ahead log from the backup file err = w.RecoverFromBackup(name) // close the log w.Close()