bytehash 0.3.0

Trait abstracting over hash-functions, allowing digests to be viewed as byte slices.
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
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72

#![deny(missing_docs)]
//! Trait abstracting over hash-functions, allowing digests to be viewed as
//! byte slices.
extern crate blake2_rfc;
extern crate byteorder;

use std::hash::{Hash, Hasher};

mod blake2b;
mod hashwrap;

pub use blake2b::Blake2b;
pub use hashwrap::Wrapped;

/// The main trait
pub trait ByteHash: 'static + Sized + Clone + Default {
    /// The type that is used for the final hash value
    type Digest: AsRef<[u8]>
        + AsMut<[u8]>
        + Copy
        + Clone
        + Eq
        + Hash
        + Default
        + Send;

    /// The state for computing hashes
    type State: State<Self::Digest> + Hasher;

    /// Construct a new hash-state
    fn state() -> Self::State;

    /// Return the hash of a type
    fn hash<T: Hash + ?Sized>(t: &T) -> Self::Digest {
        let mut state = Self::state();
        t.hash(&mut state);
        state.fin()
    }
}

/// A hash state being computed
pub trait State<D> {
    /// Consumes the state returning a hash
    fn fin(self) -> D;
}

#[cfg(test)]
mod tests {
    use super::*;
    use hashwrap::Wrapped;
    use std::collections::hash_map::DefaultHasher;

    #[test]
    fn default() {
        let mut state = Wrapped::<DefaultHasher>::state();
        state.write(b"hello world");
        state.fin();
    }

    #[test]
    fn blake2b() {
        let mut state = Blake2b::state();
        state.write(b"hello world");
        state.fin();
    }

    #[test]
    fn oneshot_hash() {
        let _hash_a = Blake2b::hash(&42u64);
        let _hash_b = Blake2b::hash("hello");
    }
}