logos-storage/plonky2
1
0
Fork 0
mirror of https://github.com/logos-storage/plonky2.git synced 2026-01-08 00:33:06 +00:00
Code Issues Packages Projects Releases Wiki Activity

Fix path compression

Browse Source
This commit is contained in:
wborgeaud 2021-10-07 22:19:26 +02:00
parent 145ee8cb18
commit 64ad8783eb
1 changed files with 44 additions and 20 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

64
src/hash/path_compression.rs
View File

@ -22,7 +22,9 @@ pub(crate) fn compress_merkle_proofs<F: Field>(
let mut known = vec![false; 2 * num_leaves];
for &i in indices {
// The leaves are known.
known[i + num_leaves] = true;
for j in 0..(height - cap_height) {
known[(i + num_leaves) >> j] = true;
}
}
// For each proof collect all the unknown proof elements.
for (&i, p) in indices.iter().zip(proofs) {
@ -66,31 +68,41 @@ pub(crate) fn decompress_merkle_proofs<F: RichField>(
// Observe the leaves.
seen.insert(i + num_leaves, hash_or_noop(v.to_vec()));
}
// For every index, go up the tree by querying `seen` to get node values, or if they are unknown
// get them from the compressed proof.
for (&i, p) in leaves_indices.iter().zip(compressed_proofs) {
let mut compressed_siblings = p.siblings.into_iter();
let mut decompressed_proof = MerkleProof {
siblings: Vec::new(),
};
let mut index = i + num_leaves;
let mut current_digest = seen[&index];
for _ in 0..height - cap_height {
let mut proofs = compressed_proofs
.iter()
.map(|p| p.siblings.iter())
.collect::<Vec<_>>();
for depth in 0..height - cap_height {
for (&i, p) in leaves_indices.iter().zip(proofs.iter_mut()) {
let index = (i + num_leaves) >> depth;
let sibling_index = index ^ 1;
// Get the value of the sibling node by querying it or getting it from the proof.
// dbg!(i, depth, index, sibling_index);
let h = *seen
.entry(sibling_index)
.or_insert_with(|| compressed_siblings.next().unwrap());
decompressed_proof.siblings.push(h);
// Update the current digest to the value of the parent.
current_digest = if index.is_even() {
.or_insert_with(|| *p.next().unwrap());
seen.insert(sibling_index, h);
let current_digest = seen[&index];
let current_digest = if index.is_even() {
compress(current_digest, h)
} else {
compress(h, current_digest)
};
// Observe the parent.
seen.insert(index >> 1, current_digest);
}
}
// For every index, go up the tree by querying `seen` to get node values, or if they are unknown
// get them from the compressed proof.
for (&i, p) in leaves_indices.iter().zip(compressed_proofs) {
let mut decompressed_proof = MerkleProof {
siblings: Vec::new(),
};
let mut index = i + num_leaves;
for _ in 0..height - cap_height {
let sibling_index = index ^ 1;
// dbg!(index, sibling_index);
let h = seen[&sibling_index];
decompressed_proof.siblings.push(h);
index >>= 1;
seen.insert(index, current_digest);
}
decompressed_proofs.push(decompressed_proof);
@ -111,17 +123,29 @@ mod tests {
#[test]
fn test_path_compression() {
type F = CrandallField;
let h = 10;
let cap_height = 3;
let h = 5;
let cap_height = 0;
let vs = (0..1 << h).map(|_| vec![F::rand()]).collect::<Vec<_>>();
let mt = MerkleTree::new(vs.clone(), cap_height);
let mut rng = thread_rng();
let k = rng.gen_range(1..=1 << h);
let k = 8;
let indices = (0..k).map(|_| rng.gen_range(0..1 << h)).collect::<Vec<_>>();
let indices = [14, 8, 15, 2, 20, 3, 7, 30];
let proofs = indices.iter().map(|&i| mt.prove(i)).collect::<Vec<_>>();
let compressed_proofs = compress_merkle_proofs(cap_height, &indices, &proofs);
// for p in &compressed_proofs {
// dbg!(&p.siblings.len());
// }
// println!(
// "{}",
// compressed_proofs
// .iter()
// .map(|p| p.siblings.len())
// .sum::<usize>()
// );
let decompressed_proofs = decompress_merkle_proofs(
&indices.iter().map(|&i| vs[i].clone()).collect::<Vec<_>>(),
&indices,