How to scan through really huge files on disk?

Question

Considering a really huge file(maybe more than 4GB) on disk,I want to scan through this file and calculate the times of a specific binary pattern occurs.

My thought

Answer 1

Although you can use memory mapping, you don't have to. If you read the file sequentially in small chunks, say 1 MB each, the file will never be present in memory all at once.

If your search code is actually slower than your hard disk, you can still hand chunks off to worker threads if you like.