Streaming hash

[Axenow]

Hi.
I try to calculate the hash of a file and it always different if I change the size of chunks.
What do I do wrong?

    {
        let mut count: usize = 0;
        let mut hasher = xxh3::Hash128::with_seed(0);

        let mut f = File::open("Cargo.lock").expect("no file found");

        let mut buffer = vec![0; 256];
        while let Ok(n) = f.read(&mut buffer[..]) {
            hasher.write(&buffer);
            count += n;
            if n != 256 {
                break;
            }
        }

        println!("256: {:x}, {}", hasher.finish_ext(), count);
    }
    {
        let mut count: usize = 0;
        let mut hasher = xxh3::Hash128::with_seed(0);

        let mut f = File::open("Cargo.lock").expect("no file found");

        let mut buffer = vec![0; 240];
        while let Ok(n) = f.read(&mut buffer[..]) {
            hasher.write(&buffer);
            count += n;
            if n != 240 {
                break;
            }
        }

        println!("240: {:x}, {}", hasher.finish_ext(), count);
    }
    {
        let mut count: usize = 0;
        let mut hasher = xxh3::Hash128::with_seed(0);

        let mut f = File::open("Cargo.lock").expect("no file found");

        let mut buffer = vec![0; 200];
        while let Ok(n) = f.read(&mut buffer[..]) {
            hasher.write(&buffer);
            count += n;
            if n != 200 {
                break;
            }
        }

        println!("200: {:x}, {}", hasher.finish_ext(), count);
    }
    {
        let mut f = File::open("Cargo.lock").expect("no file found");
        let metadata = fs::metadata("Cargo.lock").expect("Unable to read metadata");

        let mut hasher = xxh3::Hash128::with_seed(0);
        let mut buffer = vec![0; metadata.len() as usize];
        f.read(&mut buffer[..]).expect("Can't read file");
        hasher.write(&buffer);

        println!("full: {:x}, {}", hasher.finish_ext(), buffer.len());
        // println!("{} == {}", count, metadata.len());
    }

The result is

256: 1ee448053144f22d2cbdbe45196fa5c6, 2824
240: 6ac3bc90beb022a8831158d0eb34a124, 2824
200: d700e496e7318a85318e88499afc3053, 2824
full: 7d86bdc8cdbe9934871303e33b3c2aeb, 2824

[Axenow]

Please, close the issue.
I'm a bit new in Rust and made the mistake in the code.
Sorry.