mithril_stm/merkle_tree/
leaf.rs

1use crate::error::MerkleTreeError;
2use crate::multi_sig::VerificationKey;
3use crate::stm::{Stake, StmVerificationKey};
4use blake2::Blake2b;
5use digest::consts::U32;
6use serde::{Deserialize, Serialize};
7use std::cmp::Ordering;
8
9/// The values that are committed in the Merkle Tree.
10/// Namely, a verified `VerificationKey` and its corresponding stake.
11#[derive(Debug, Clone, Copy, Default, PartialEq, Eq, Serialize, Deserialize, Hash)]
12pub struct MTLeaf(pub VerificationKey, pub Stake);
13
14impl MTLeaf {
15    pub(crate) fn from_bytes(bytes: &[u8]) -> Result<Self, MerkleTreeError<Blake2b<U32>>> {
16        let pk = StmVerificationKey::from_bytes(bytes)
17            .map_err(|_| MerkleTreeError::SerializationError)?;
18        let mut u64_bytes = [0u8; 8];
19        u64_bytes.copy_from_slice(&bytes[96..]);
20        let stake = Stake::from_be_bytes(u64_bytes);
21        Ok(MTLeaf(pk, stake))
22    }
23    pub(crate) fn to_bytes(self) -> [u8; 104] {
24        let mut result = [0u8; 104];
25        result[..96].copy_from_slice(&self.0.to_bytes());
26        result[96..].copy_from_slice(&self.1.to_be_bytes());
27        result
28    }
29}
30
31impl From<MTLeaf> for (StmVerificationKey, Stake) {
32    fn from(leaf: MTLeaf) -> (StmVerificationKey, Stake) {
33        (leaf.0, leaf.1)
34    }
35}
36
37impl PartialOrd for MTLeaf {
38    /// Ordering of MT Values.
39    ///
40    /// First we order by stake, then by key. By having this ordering,
41    /// we have the players with higher stake close together,
42    /// meaning that the probability of having several signatures in the same side of the tree, is higher.
43    /// This allows us to produce a more efficient batch opening of the merkle tree.
44    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
45        Some(std::cmp::Ord::cmp(self, other))
46    }
47}
48
49impl Ord for MTLeaf {
50    fn cmp(&self, other: &Self) -> Ordering {
51        self.1.cmp(&other.1).then(self.0.cmp(&other.0))
52    }
53}
mithril_stm/merkle_tree/leaf.rs

mithril_stm/merkle_tree/
leaf.rs
