1use node;
 2use tiny_keccak::Keccak;
 3
 4pub fn hash_vec(b: Vec<u8>) -> [u8; 32] {
 5    let mut sha3 = Keccak::new_keccak256();
 6    sha3.update(&b);
 7    let mut res: [u8; 32] = [0; 32];
 8    sha3.finalize(&mut res);
 9    res
10}
11
12#[allow(dead_code)]
13pub fn get_path(num_levels: u32, hi: [u8;32]) -> Vec<bool> {
14    let mut path = Vec::new();
15    for i in (0..=num_levels as usize-2).rev() {
16        path.push((hi[hi.len()-i/8-1] & (1 << (i%8))) > 0);
17    }
18    path
19}
20
21#[allow(dead_code)]
22pub fn calc_hash_from_leaf_and_level(until_level: u32, path: &[bool], leaf_hash: [u8;32]) -> [u8;32] {
23    let mut node_curr_lvl = leaf_hash;
24    for i in 0..until_level {
25        if path[i as usize] {
26            let node = node::TreeNode {
27                child_l: ::EMPTYNODEVALUE,
28                child_r: node_curr_lvl,
29            };
30            node_curr_lvl = node.ht();
31        } else {
32            let node = node::TreeNode {
33                child_l: node_curr_lvl,
34                child_r: ::EMPTYNODEVALUE,
35            };
36            node_curr_lvl = node.ht();
37        }
38    }
39    node_curr_lvl
40}
41
42pub fn cut_path(path: &[bool], i: usize) -> Vec<bool> {
43    let mut path_res: Vec<bool> = Vec::new();
44    for j in 0..path.len() {
45        if j>=i {
46            path_res.push(path[j]);
47        }
48    }
49    path_res
50}
51
52pub fn compare_paths(a: &[bool], b: &[bool]) -> u32 {
53    for i in (0..a.len()).rev() {
54        if a[i] != b[i] {
55            return i as u32;
56        }
57    }
58    999
59}
60
61pub fn get_empties_between_i_and_pos(i: u32, pos: u32) -> Vec<[u8;32]> {
62    let mut sibl: Vec<[u8;32]> = Vec::new();
63    for _ in (pos..=i).rev() {
64        sibl.push(::EMPTYNODEVALUE);
65    }
66    sibl
67}
68
69#[cfg(test)]
70mod tests {
71    use super::*;
72    use rustc_hex::ToHex;
73
74    #[test]
75    fn test_hash_vec() {
76        let a: Vec<u8> = From::from("test");
77        assert_eq!("74657374", a.to_hex());
78        let h = hash_vec(a);
79        assert_eq!("9c22ff5f21f0b81b113e63f7db6da94fedef11b2119b4088b89664fb9a3cb658", h.to_hex());
80    }
81}