Question

I would like to know the difference in terms of performance between these two blocks that try to send a big file over a TCP socket.
I couldn’t find much resources explaining their efficiency.

A-

byte[] buffer = new byte[1024];
int number;

while ((number = fileInputStream.read(buffer)) != -1) {
socketOutputStream.write(buffer, 0, number);
}

B-

byte mybytearray = new byte[filesize];
os.write(mybytearray);

Which one is better in terms of transfer delay?

Also What is the difference if i set the size to 1024 or 65536? How would that affect the performance.

Answer 1

The latency until the last byte of the file arrives is basically identical. However the first one is preferable, although with a much larger buffer, for the following reasons:

1. The data starts arriving sooner.
2. There is no assumption that the file size fits into an int.
3. There is no assumption that the entire file fits into memory, so
4. It scales to very large files without code changes.