What is the most efficient way to read a large file in chunks without loading the entire file in memory at once?

Question

What is the most efficient general purpose way of reading \"large\" files (which may be text or binary), without going into unsafe territory? I was surprised ho

Answer 1

I don't think you can write code more efficient than that. fill_buf on a BufReader over a File is basically just a straight call to read(2).

That said, BufReader isn't really a useful abstraction when you use it like that; it would probably be less awkward to just call file.read(&mut buf) directly.