snarkvm_ledger_block/ratifications/
merkle.rs

1// Copyright (c) 2019-2025 Provable Inc.
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> Ratifications<N> {
19    /// Returns the ratifications root, by computing the root for a Merkle tree of the ratification IDs.
20    pub fn to_ratifications_root(&self) -> Result<Field<N>> {
21        Ok(*self.to_tree()?.root())
22    }
23
24    /// Returns the Merkle path for the ratifications leaf.
25    pub fn to_path(&self, ratification_id: N::RatificationID) -> Result<RatificationsPath<N>> {
26        match self.ratifications.get_index_of(&ratification_id) {
27            Some(ratification_index) => self.to_tree()?.prove(ratification_index, &ratification_id.to_bits_le()),
28            None => bail!("The ratification '{ratification_id}' is not in the block ratifications"),
29        }
30    }
31
32    /// The Merkle tree of ratification IDs for the block.
33    pub fn to_tree(&self) -> Result<RatificationsTree<N>> {
34        Self::ratifications_tree(self.ratifications.keys())
35    }
36
37    /// Returns the Merkle tree for the given ratifications.
38    fn ratifications_tree<'a>(
39        ratifications: impl ExactSizeIterator<Item = &'a N::RatificationID>,
40    ) -> Result<RatificationsTree<N>> {
41        // Ensure the number of ratifications is within the allowed range.
42        ensure!(
43            ratifications.len() <= Self::MAX_RATIFICATIONS,
44            "Block cannot exceed {} ratifications, found {}",
45            Self::MAX_RATIFICATIONS,
46            ratifications.len()
47        );
48        // Prepare the leaves.
49        let leaves = ratifications.map(|id| id.to_bits_le());
50        // Compute the ratifications tree.
51        N::merkle_tree_bhp::<RATIFICATIONS_DEPTH>(&leaves.collect::<Vec<_>>())
52    }
53}
54
55#[cfg(test)]
56mod tests {
57    use super::*;
58    use console::network::MainnetV0;
59
60    type CurrentNetwork = MainnetV0;
61
62    #[test]
63    fn test_ratifications_depth() {
64        // Ensure the log2 relationship between depth and the maximum number of ratifications.
65        assert_eq!(2usize.pow(RATIFICATIONS_DEPTH as u32), Ratifications::<CurrentNetwork>::MAX_RATIFICATIONS);
66    }
67}