blob: 5abc968bb1db78d047a5caa594ba93dcf9d60bb8 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
|
//! Utility functions that don't fit anywhere else.
pub fn read_be_u64(b: &[u8]) -> u64 {
assert_eq!(b.len(), 8);
((b[0] as u64) << 56) as u64
| ((b[1] as u64) << 48)
| ((b[2] as u64) << 40)
| ((b[3] as u64) << 32)
| ((b[4] as u64) << 24)
| ((b[5] as u64) << 16)
| ((b[6] as u64) << 8)
| ((b[7] as u64) << 0)
}
pub fn write_be_u64(b: &mut [u8], n: u64) {
assert_eq!(b.len(), 8);
b[0] = (n >> 56) as u8;
b[1] = (n >> 48) as u8;
b[2] = (n >> 40) as u8;
b[3] = (n >> 32) as u8;
b[4] = (n >> 24) as u8;
b[5] = (n >> 16) as u8;
b[6] = (n >> 8) as u8;
b[7] = (n >> 0) as u8;
}
#[cfg(test)]
mod test {
use super::*;
quickcheck! {
fn be_u64_roundtrip(n: u64) -> bool {
let mut b = [0; 8];
write_be_u64(&mut b, n);
n == read_be_u64(&b)
}
}
}
|
