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

// Copyright (C) 2019-2023 Aleo Systems Inc.
// This file is part of the snarkVM library.

// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at:
// http://www.apache.org/licenses/LICENSE-2.0

// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

use super::*;

impl<N: Network> FromBytes for EpochChallenge<N> {
    /// Reads the epoch challenge from a buffer.
    fn read_le<R: Read>(mut reader: R) -> IoResult<Self> {
        // Read the epoch number.
        let epoch_number = FromBytes::read_le(&mut reader)?;
        // Read the epoch block hash.
        let epoch_block_hash = FromBytes::read_le(&mut reader)?;
        // Read the epoch degree.
        let degree = FromBytes::read_le(&mut reader)?;
        // Return the epoch challenge.
        Self::new(epoch_number, epoch_block_hash, degree).map_err(|e| error(e.to_string()))
    }
}

impl<N: Network> ToBytes for EpochChallenge<N> {
    /// Writes the epoch challenge to a buffer.
    fn write_le<W: Write>(&self, mut writer: W) -> IoResult<()> {
        // Write the epoch number.
        self.epoch_number.write_le(&mut writer)?;
        // Write the epoch block hash.
        self.epoch_block_hash.write_le(&mut writer)?;
        // Write the epoch degree.
        self.degree().write_le(&mut writer)
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use console::network::Testnet3;

    use rand::RngCore;

    type CurrentNetwork = Testnet3;

    const ITERATIONS: usize = 100;

    #[test]
    fn test_bytes() {
        let mut rng = TestRng::default();

        for _ in 0..ITERATIONS {
            // Sample a new epoch challenge.
            let degree: u16 = rng.gen(); // Bound the maximal test degree to 2^16.
            let expected = EpochChallenge::<CurrentNetwork>::new(rng.next_u32(), rng.gen(), degree as u32).unwrap();

            // Check the byte representation.
            let expected_bytes = expected.to_bytes_le().unwrap();
            let candidate = EpochChallenge::read_le(&expected_bytes[..]).unwrap();
            assert_eq!(expected.epoch_number(), candidate.epoch_number());
            assert_eq!(expected.epoch_block_hash(), candidate.epoch_block_hash());
            assert_eq!(expected.degree(), candidate.degree());
            assert_eq!(expected, candidate);

            assert!(EpochChallenge::<CurrentNetwork>::read_le(&expected_bytes[1..]).is_err());
        }
    }
}