snops-common 0.1.0

Common types and utilities for snops
Documentation 
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
39
40
41
42
43
44
45
46
47
48
49

use std::{fmt::Debug, io::Read, path::PathBuf};

use sha2::{Digest, Sha256};

/// A wrapper struct that has an "opaque" `Debug` implementation for types
/// that do not implement `Debug`.
pub struct OpaqueDebug<T>(pub T);

impl<T: Default> Default for OpaqueDebug<T> {
    fn default() -> Self {
        Self(T::default())
    }
}

impl<T> Debug for OpaqueDebug<T> {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        f.write_str("(...)")
    }
}

impl<T> std::ops::Deref for OpaqueDebug<T> {
    type Target = T;

    fn deref(&self) -> &Self::Target {
        &self.0
    }
}

impl<T> std::ops::DerefMut for OpaqueDebug<T> {
    fn deref_mut(&mut self) -> &mut Self::Target {
        &mut self.0
    }
}

/// Calculate the SHA-256 hash of a file.
pub fn sha256_file(path: &PathBuf) -> Result<String, std::io::Error> {
    let mut digest = Sha256::new();
    let mut file = std::fs::File::open(path)?;
    let mut buffer = [0; 1024];
    loop {
        let n = file.read(&mut buffer)?;
        if n == 0 {
            break;
        }
        digest.update(&buffer[..n]);
    }

    Ok(format!("{:x}", digest.finalize()))
}