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use super::constants;
use super::node;
use tiny_keccak::Keccak;
pub fn hash_vec(b: Vec<u8>) -> [u8; 32] {
let mut sha3 = Keccak::new_keccak256();
sha3.update(&b);
let mut res: [u8; 32] = [0; 32];
sha3.finalize(&mut res);
res
}
pub fn get_path(num_levels: u32, hi: [u8; 32]) -> Vec<bool> {
let mut path = Vec::new();
for i in (0..=num_levels as usize - 2).rev() {
path.push((hi[hi.len() - i / 8 - 1] & (1 << (i % 8))) > 0);
}
path
}
pub fn calc_hash_from_leaf_and_level(
until_level: u32,
path: &[bool],
leaf_hash: [u8; 32],
) -> [u8; 32] {
let mut node_curr_lvl = leaf_hash;
for i in 0..until_level {
if path[i as usize] {
let node = node::TreeNode {
child_l: constants::EMPTYNODEVALUE,
child_r: node_curr_lvl,
};
node_curr_lvl = node.ht();
} else {
let node = node::TreeNode {
child_l: node_curr_lvl,
child_r: constants::EMPTYNODEVALUE,
};
node_curr_lvl = node.ht();
}
}
node_curr_lvl
}
pub fn cut_path(path: &[bool], i: usize) -> Vec<bool> {
let mut path_res: Vec<bool> = Vec::new();
for j in 0..path.len() {
if j >= i {
path_res.push(path[j]);
}
}
path_res
}
pub fn compare_paths(a: &[bool], b: &[bool]) -> i32 {
for i in (0..a.len()).rev() {
if a[i] != b[i] {
return i as i32;
}
}
-1
}
pub fn get_empties_between_i_and_pos(i: u32, pos: u32) -> Vec<[u8; 32]> {
let mut sibl: Vec<[u8; 32]> = Vec::new();
for _ in (pos..=i).rev() {
sibl.push(constants::EMPTYNODEVALUE);
}
sibl
}
#[cfg(test)]
mod tests {
use super::*;
use rustc_hex::ToHex;
#[test]
fn test_hash_vec() {
let a: Vec<u8> = From::from("test");
assert_eq!("74657374", a.to_hex());
let h = hash_vec(a);
assert_eq!(
"9c22ff5f21f0b81b113e63f7db6da94fedef11b2119b4088b89664fb9a3cb658",
h.to_hex()
);
}
}
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