oasis_contract_sdk_types/
token.rs

1//! Token types.
2use std::{convert::TryFrom, fmt};
3
4/// Name/type of the token.
5#[derive(Clone, Debug, Default, PartialEq, Eq, PartialOrd, Ord, cbor::Encode)]
6#[cbor(transparent)]
7pub struct Denomination(Vec<u8>);
8
9impl Denomination {
10    /// Maximum length of a denomination.
11    pub const MAX_LENGTH: usize = 32;
12    /// Denomination in native token.
13    pub const NATIVE: Denomination = Denomination(Vec::new());
14
15    /// Whether the denomination represents the native token.
16    pub fn is_native(&self) -> bool {
17        self.0.is_empty()
18    }
19
20    /// Raw representation of a denomination.
21    pub fn into_vec(self) -> Vec<u8> {
22        self.0
23    }
24}
25
26impl AsRef<[u8]> for Denomination {
27    fn as_ref(&self) -> &[u8] {
28        &self.0
29    }
30}
31
32impl fmt::Display for Denomination {
33    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
34        if self.is_native() {
35            write!(f, "<native>")?;
36        } else {
37            write!(f, "{}", String::from_utf8_lossy(&self.0))?;
38        }
39        Ok(())
40    }
41}
42
43impl std::str::FromStr for Denomination {
44    type Err = Error;
45
46    fn from_str(v: &str) -> Result<Self, Self::Err> {
47        Self::try_from(v.as_bytes())
48    }
49}
50
51impl TryFrom<&[u8]> for Denomination {
52    type Error = Error;
53
54    fn try_from(bytes: &[u8]) -> Result<Self, Self::Error> {
55        if bytes.len() > Self::MAX_LENGTH {
56            return Err(Error::NameTooLong {
57                length: bytes.len(),
58            });
59        }
60        Ok(Self(bytes.to_vec()))
61    }
62}
63
64impl cbor::Decode for Denomination {
65    fn try_default() -> Result<Self, cbor::DecodeError> {
66        Ok(Default::default())
67    }
68
69    fn try_from_cbor_value(value: cbor::Value) -> Result<Self, cbor::DecodeError> {
70        match value {
71            cbor::Value::ByteString(data) => {
72                Self::try_from(data.as_ref()).map_err(|_| cbor::DecodeError::UnexpectedType)
73            }
74            _ => Err(cbor::DecodeError::UnexpectedType),
75        }
76    }
77}
78
79#[cfg(feature = "oasis-runtime-sdk")]
80impl From<oasis_runtime_sdk::types::token::Denomination> for Denomination {
81    fn from(d: oasis_runtime_sdk::types::token::Denomination) -> Self {
82        Self(d.into_vec())
83    }
84}
85
86#[cfg(feature = "oasis-runtime-sdk")]
87impl From<Denomination> for oasis_runtime_sdk::types::token::Denomination {
88    fn from(d: Denomination) -> Self {
89        oasis_runtime_sdk::types::token::Denomination::try_from(d.0.as_ref()).unwrap()
90    }
91}
92
93#[derive(Debug, thiserror::Error)]
94pub enum Error {
95    #[error(
96        "denomination name too long. received length {length} exceeded maximum of {}",
97        Denomination::MAX_LENGTH
98    )]
99    NameTooLong { length: usize },
100}
101
102/// Token amount of given denomination in base units.
103#[derive(Clone, Debug, Default, PartialEq, Eq, PartialOrd, Ord, cbor::Encode, cbor::Decode)]
104pub struct BaseUnits(pub u128, pub Denomination);
105
106impl BaseUnits {
107    /// Creates a new token amount of the given denomination.
108    pub fn new(amount: u128, denomination: Denomination) -> Self {
109        BaseUnits(amount, denomination)
110    }
111
112    /// Token amount in base units.
113    pub fn amount(&self) -> u128 {
114        self.0
115    }
116
117    /// Denomination of the token amount.
118    pub fn denomination(&self) -> &Denomination {
119        &self.1
120    }
121}
122
123impl fmt::Display for BaseUnits {
124    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
125        write!(f, "{} {}", self.0, self.1)?;
126        Ok(())
127    }
128}
129
130#[cfg(feature = "oasis-runtime-sdk")]
131impl From<oasis_runtime_sdk::types::token::BaseUnits> for BaseUnits {
132    fn from(a: oasis_runtime_sdk::types::token::BaseUnits) -> Self {
133        Self(a.0, a.1.into())
134    }
135}
136
137#[cfg(feature = "oasis-runtime-sdk")]
138impl From<&oasis_runtime_sdk::types::token::BaseUnits> for BaseUnits {
139    fn from(a: &oasis_runtime_sdk::types::token::BaseUnits) -> Self {
140        Self(a.0, a.1.clone().into())
141    }
142}
143
144#[cfg(test)]
145mod test {
146    use super::*;
147
148    #[test]
149    fn test_basic() {
150        let cases = vec![
151            // Native denomination.
152            (0, Denomination::NATIVE, "824040"),
153            (1, Denomination::NATIVE, "82410140"),
154            (1000, Denomination::NATIVE, "824203e840"),
155            // Custom denomination.
156            (0, "test".parse().unwrap(), "82404474657374"),
157            (1, "test".parse().unwrap(), "8241014474657374"),
158            (1000, "test".parse().unwrap(), "824203e84474657374"),
159        ];
160
161        for tc in cases {
162            let token = BaseUnits::new(tc.0, tc.1);
163            let enc = cbor::to_vec(token.clone());
164            assert_eq!(hex::encode(&enc), tc.2, "serialization should match");
165
166            let dec: BaseUnits = cbor::from_slice(&enc).expect("deserialization should succeed");
167            assert_eq!(dec, token, "serialization should round-trip");
168        }
169    }
170
171    #[test]
172    fn test_decoding_denomination() {
173        macro_rules! assert_rountrip_ok {
174            ($bytes:expr) => {
175                let enc = cbor::to_vec($bytes.to_vec());
176                let dec: Denomination = cbor::from_slice(&enc).unwrap();
177                assert_eq!(dec, Denomination::try_from($bytes).unwrap());
178                assert_eq!(dec.0, $bytes);
179            };
180        }
181
182        let bytes_fixture = vec![42u8; Denomination::MAX_LENGTH + 1];
183
184        assert_rountrip_ok!(&bytes_fixture[0..0]);
185        assert_rountrip_ok!(&bytes_fixture[0..1]);
186        assert_rountrip_ok!(&bytes_fixture[0..Denomination::MAX_LENGTH]);
187
188        // Too long denomination:
189        let dec_result: Result<Denomination, _> = cbor::from_slice(&cbor::to_vec(bytes_fixture));
190        assert!(dec_result.is_err());
191    }
192}
oasis_contract_sdk_types/token.rs

oasis_contract_sdk_types/
token.rs
