1use node;
 2use tiny_keccak::Keccak;
 3
 4pub fn hash_vec(b: Vec<u8>) -> [u8; 32] {
 5    // let mut sha3 = Keccak::new_sha3_256();
 6    let mut sha3 = Keccak::new_keccak256();
 7    sha3.update(&b);
 8    let mut res: [u8; 32] = [0; 32];
 9    sha3.finalize(&mut res);
10    res
11}
12
13#[allow(dead_code)]
14pub fn get_path(num_levels: u32, hi: [u8;32]) -> Vec<bool> {
15    let mut path = Vec::new();
16    for i in (0..num_levels as usize-1).rev() {
17        path.push((hi[hi.len()-i/8-1] & (1 << (i%8))) > 0);
18    }
19    path
20}
21
22#[allow(dead_code)]
23pub fn calc_hash_from_leaf_and_level(until_level: u32, path: &[bool], leaf_hash: [u8;32]) -> [u8;32] {
24    let mut node_curr_lvl = leaf_hash;
25    for i in 0..until_level {
26        if path[i as usize] {
27            let node = node::TreeNode {
28                child_l: ::EMPTYNODEVALUE,
29                child_r: node_curr_lvl,
30            };
31            node_curr_lvl = node.ht();
32        } else {
33            let node = node::TreeNode {
34                child_l: node_curr_lvl,
35                child_r: ::EMPTYNODEVALUE,
36            };
37            node_curr_lvl = node.ht();
38        }
39    }
40    node_curr_lvl
41}
42
43pub fn cut_path(path: &[bool], i: usize) -> Vec<bool> {
44    let mut path_res: Vec<bool> = Vec::new();
45    for (j, path_elem) in path.iter().enumerate() {
46        if j >= i {
47            path_res.push(*path_elem);
48        }
49    }
50    path_res
51}
52
53pub fn compare_paths(a: &[bool], b: &[bool]) -> u32 {
54    for i in (0..a.len()).rev() {
55        if a[i] != b[i] {
56            return i as u32;
57        }
58    }
59    999
60}
61
62pub fn get_empties_between_i_and_pos(i: u32, pos: u32) -> Vec<[u8;32]> {
63    let mut sibl: Vec<[u8;32]> = Vec::new();
64    for _j in (pos..i).rev() {
65        sibl.push(::EMPTYNODEVALUE);
66    }
67    sibl.to_vec()
68}
69
70#[cfg(test)]
71mod tests {
72    use super::*;
73    use rustc_hex::ToHex;
74
75    #[test]
76    fn test_hash_vec() {
77        let a: Vec<u8> = From::from("test");
78        assert_eq!("74657374", a.to_hex());
79        let h = hash_vec(a);
80        assert_eq!("9c22ff5f21f0b81b113e63f7db6da94fedef11b2119b4088b89664fb9a3cb658", h.to_hex());
81    }
82}