snarkvm_console_program/data/identifier/
bytes.rs

1// Copyright 2024 Aleo Network Foundation
2// This file is part of the snarkVM library.
3
4// Licensed under the Apache License, Version 2.0 (the "License");
5// you may not use this file except in compliance with the License.
6// You may obtain a copy of the License at:
7
8// http://www.apache.org/licenses/LICENSE-2.0
9
10// Unless required by applicable law or agreed to in writing, software
11// distributed under the License is distributed on an "AS IS" BASIS,
12// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13// See the License for the specific language governing permissions and
14// limitations under the License.
15
16use super::*;
17
18impl<N: Network> FromBytes for Identifier<N> {
19    /// Reads in an identifier from a buffer.
20    fn read_le<R: Read>(mut reader: R) -> IoResult<Self> {
21        // Read the number of bytes.
22        let size = u8::read_le(&mut reader)?;
23
24        // Read the identifier bytes.
25        let mut buffer = vec![0u8; size as usize];
26        reader.read_exact(&mut buffer)?;
27
28        // from_str the identifier.
29        // Note: `Self::from_str` ensures that the identifier string is not empty.
30        Self::from_str(&String::from_utf8(buffer).map_err(|e| error(format!("Failed to decode identifier: {e}")))?)
31            .map_err(|e| error(format!("{e}")))
32    }
33}
34
35impl<N: Network> ToBytes for Identifier<N> {
36    /// Writes an identifier to a buffer.
37    fn write_le<W: Write>(&self, mut writer: W) -> IoResult<()> {
38        // Convert the identifier to a string.
39        let string = self.to_string();
40        if string.len() != self.1 as usize {
41            return Err(error("Identifier length does not match expected size"));
42        }
43
44        // Ensure identifier fits within the data capacity of the base field.
45        let max_bytes = Field::<N>::size_in_data_bits() / 8; // Note: This intentionally rounds down.
46        if string.len() > max_bytes {
47            return Err(error(format!("Identifier is too large. Identifiers must be <= {max_bytes} bytes long")));
48        }
49
50        // Write the identifier to a buffer.
51        u8::try_from(string.len()).or_halt_with::<N>("Invalid identifier length").write_le(&mut writer)?;
52        string.as_bytes().write_le(&mut writer)
53    }
54}
55
56#[cfg(test)]
57mod tests {
58    use super::*;
59    use crate::data::identifier::tests::sample_identifier;
60    use snarkvm_console_network::MainnetV0;
61
62    type CurrentNetwork = MainnetV0;
63
64    const ITERATIONS: u64 = 1000;
65
66    #[test]
67    fn test_bytes() -> Result<()> {
68        let mut rng = TestRng::default();
69
70        for _ in 0..ITERATIONS {
71            // Sample a random fixed-length alphanumeric identifier, that always starts with an alphabetic character.
72            let expected = sample_identifier::<CurrentNetwork>(&mut rng)?;
73
74            // Check the byte representation.
75            let expected_bytes = expected.to_bytes_le()?;
76            assert_eq!(expected, Identifier::read_le(&expected_bytes[..])?);
77        }
78        Ok(())
79    }
80
81    #[test]
82    fn test_zero_identifier_fails() {
83        assert!(Identifier::<CurrentNetwork>::read_le(&[0u8; 1][..]).is_err())
84    }
85}
snarkvm_console_program/data/identifier/bytes.rs

snarkvm_console_program/data/identifier/
bytes.rs
