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
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102

use std::mem;
use std::str::FromStr;
use {
    crate::{
        sanitize::Sanitize,
    },
    serde_derive::{Serialize,Deserialize},
    borsh::{
        BorshDeserialize, BorshSerialize,
    },
    borsh_derive::BorshSchema,
    std::{
        fmt,
    },
    thiserror::Error,
};

/// Size of a hash in bytes.
pub const HASH_BYTES: usize = 32;
/// Maximum string length of a base58 encoded hash.
const MAX_BASE58_LEN: usize = 44;

/// A hash; the 32-byte output of a hashing algorithm.
#[derive(
    Serialize,
    Deserialize,
    BorshSerialize,
    BorshDeserialize,
    BorshSchema,
    Clone,
    Copy,
    Default,
    Eq,
    PartialEq,
    Ord,
    PartialOrd,
    Hash,
)]
#[repr(transparent)]
pub struct Hash(pub(crate) [u8; HASH_BYTES]);

impl Hash {
    pub fn new(hash_slice: &[u8]) -> Self {
        Hash(<[u8; HASH_BYTES]>::try_from(hash_slice).unwrap())
    }

    pub fn to_bytes(self) -> [u8; HASH_BYTES] {
        self.0
    }
}

impl Sanitize for Hash {}

impl From<[u8; HASH_BYTES]> for Hash {
    fn from(from: [u8; 32]) -> Self {
        Self(from)
    }
}

impl AsRef<[u8]> for Hash {
    fn as_ref(&self) -> &[u8] {
        &self.0[..]
    }
}

impl fmt::Debug for Hash {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        write!(f, "{}", bs58::encode(self.0).into_string())
    }
}

impl fmt::Display for Hash {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        write!(f, "{}", bs58::encode(self.0).into_string())
    }
}

#[derive(Debug, Clone, PartialEq, Eq, Error)]
pub enum ParseHashError {
    #[error("string decoded to wrong size for hash")]
    WrongSize,
    #[error("failed to decoded string to hash")]
    Invalid,
}

impl FromStr for Hash {
    type Err = ParseHashError;

    fn from_str(s: &str) -> Result<Self, Self::Err> {
        if s.len() > MAX_BASE58_LEN {
            return Err(ParseHashError::WrongSize);
        }
        let bytes = bs58::decode(s)
            .into_vec()
            .map_err(|_| ParseHashError::Invalid)?;
        if bytes.len() != mem::size_of::<Hash>() {
            Err(ParseHashError::WrongSize)
        } else {
            Ok(Hash::new(&bytes))
        }
    }
}