1  // Copyright (c) 2019-2025 Alpha-Delta Network Inc.
 2  // This file is part of the alphavm 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  
16  use super::*;
17  
18  impl<N: Network> BatchHeader<N> {
19      /// Returns the batch ID.
20      pub fn to_id(&self) -> Result<Field<N>> {
21          Self::compute_batch_id(
22              self.author,
23              self.round,
24              self.timestamp,
25              self.committee_id,
26              &self.transmission_ids,
27              &self.previous_certificate_ids,
28          )
29      }
30  }
31  
32  impl<N: Network> BatchHeader<N> {
33      /// Returns the batch ID.
34      pub fn compute_batch_id(
35          author: Address<N>,
36          round: u64,
37          timestamp: i64,
38          committee_id: Field<N>,
39          transmission_ids: &IndexSet<TransmissionID<N>>,
40          previous_certificate_ids: &IndexSet<Field<N>>,
41      ) -> Result<Field<N>> {
42          let mut preimage = Vec::new();
43          // Insert the author.
44          author.write_le(&mut preimage)?;
45          // Insert the round number.
46          round.write_le(&mut preimage)?;
47          // Insert the timestamp.
48          timestamp.write_le(&mut preimage)?;
49          // Insert the committee ID.
50          committee_id.write_le(&mut preimage)?;
51          // Insert the number of transmissions.
52          u32::try_from(transmission_ids.len())?.write_le(&mut preimage)?;
53          // Insert the transmission IDs.
54          for transmission_id in transmission_ids {
55              transmission_id.write_le(&mut preimage)?;
56          }
57          // Insert the number of previous certificate IDs.
58          u32::try_from(previous_certificate_ids.len())?.write_le(&mut preimage)?;
59          // Insert the previous certificate IDs.
60          for certificate_id in previous_certificate_ids {
61              // Insert the certificate ID.
62              certificate_id.write_le(&mut preimage)?;
63          }
64          // Hash the preimage.
65          N::hash_bhp1024(&preimage.to_bits_le())
66      }
67  }