boolean lineBuffered = bufsize == 1;
BufferedIOBase buffer;
if (updating) {
buffer = lineBuffered ? new LineBufferedRandom(raw) : new BufferedRandom(raw, bufsize);
} else if (writing || appending) {
buffer = lineBuffered ? new LineBufferedWriter(raw) : new BufferedWriter(raw, bufsize);
} else if (reading) {
// Line buffering is for output only
buffer = new BufferedReader(raw, lineBuffered ? IOBase.DEFAULT_BUFFER_SIZE : bufsize);
} else {
// Should never happen