307 lines
7.7 KiB
Rust
307 lines
7.7 KiB
Rust
//! Generetes trie root.
|
|
//!
|
|
//! This module should be used to generate trie root hash.
|
|
|
|
use std::collections::BTreeMap;
|
|
use std::cmp;
|
|
use hash::*;
|
|
use sha3::*;
|
|
use rlp;
|
|
use rlp::{RlpStream, Stream};
|
|
use vector::SharedPrefix;
|
|
|
|
/// Generates a trie root hash for a vector of values
|
|
///
|
|
/// ```rust
|
|
/// extern crate ethcore_util as util;
|
|
/// use std::str::FromStr;
|
|
/// use util::triehash::*;
|
|
/// use util::hash::*;
|
|
///
|
|
/// fn main() {
|
|
/// let v = vec![From::from("doe"), From::from("reindeer")];
|
|
/// let root = "e766d5d51b89dc39d981b41bda63248d7abce4f0225eefd023792a540bcffee3";
|
|
/// assert_eq!(ordered_trie_root(v), H256::from_str(root).unwrap());
|
|
/// }
|
|
/// ```
|
|
pub fn ordered_trie_root(input: Vec<Vec<u8>>) -> H256 {
|
|
let gen_input = input
|
|
// first put elements into btree to sort them by nibbles
|
|
// optimize it later
|
|
.into_iter()
|
|
.fold(BTreeMap::new(), | mut acc, vec | {
|
|
let len = acc.len();
|
|
acc.insert(rlp::encode(&len), vec);
|
|
acc
|
|
})
|
|
// then move them to a vector
|
|
.into_iter()
|
|
.map(|(k, v)| (as_nibbles(&k), v) )
|
|
.collect();
|
|
|
|
gen_trie_root(gen_input)
|
|
}
|
|
|
|
/// Generates a trie root hash for a vector of key-values
|
|
///
|
|
/// ```rust
|
|
/// extern crate ethcore_util as util;
|
|
/// use std::str::FromStr;
|
|
/// use util::triehash::*;
|
|
/// use util::hash::*;
|
|
///
|
|
/// fn main() {
|
|
/// let v = vec![
|
|
/// (From::from("doe"), From::from("reindeer")),
|
|
/// (From::from("dog"), From::from("puppy")),
|
|
/// (From::from("dogglesworth"), From::from("cat")),
|
|
/// ];
|
|
///
|
|
/// let root = "8aad789dff2f538bca5d8ea56e8abe10f4c7ba3a5dea95fea4cd6e7c3a1168d3";
|
|
/// assert_eq!(trie_root(v), H256::from_str(root).unwrap());
|
|
/// }
|
|
/// ```
|
|
pub fn trie_root(input: Vec<(Vec<u8>, Vec<u8>)>) -> H256 {
|
|
let gen_input = input
|
|
// first put elements into btree to sort them and to remove duplicates
|
|
.into_iter()
|
|
.fold(BTreeMap::new(), | mut acc, (k, v) | {
|
|
acc.insert(k, v);
|
|
acc
|
|
})
|
|
// then move them to a vector
|
|
.into_iter()
|
|
.map(|(k, v)| (as_nibbles(&k), v) )
|
|
.collect();
|
|
|
|
gen_trie_root(gen_input)
|
|
}
|
|
|
|
fn gen_trie_root(input: Vec<(Vec<u8>, Vec<u8>)>) -> H256 {
|
|
let mut stream = RlpStream::new();
|
|
hash256rlp(&input, 0, &mut stream);
|
|
stream.out().sha3()
|
|
}
|
|
|
|
/// Hex-prefix Notation. First nibble has flags: oddness = 2^0 & termination = 2^1.
|
|
///
|
|
/// The "termination marker" and "leaf-node" specifier are completely equivalent.
|
|
///
|
|
/// Input values are in range `[0, 0xf]`.
|
|
///
|
|
/// ```markdown
|
|
/// [0,0,1,2,3,4,5] 0x10012345 // 7 > 4
|
|
/// [0,1,2,3,4,5] 0x00012345 // 6 > 4
|
|
/// [1,2,3,4,5] 0x112345 // 5 > 3
|
|
/// [0,0,1,2,3,4] 0x00001234 // 6 > 3
|
|
/// [0,1,2,3,4] 0x101234 // 5 > 3
|
|
/// [1,2,3,4] 0x001234 // 4 > 3
|
|
/// [0,0,1,2,3,4,5,T] 0x30012345 // 7 > 4
|
|
/// [0,0,1,2,3,4,T] 0x20001234 // 6 > 4
|
|
/// [0,1,2,3,4,5,T] 0x20012345 // 6 > 4
|
|
/// [1,2,3,4,5,T] 0x312345 // 5 > 3
|
|
/// [1,2,3,4,T] 0x201234 // 4 > 3
|
|
/// ```
|
|
fn hex_prefix_encode(nibbles: &[u8], leaf: bool) -> Vec<u8> {
|
|
let inlen = nibbles.len();
|
|
let oddness_factor = inlen % 2;
|
|
// next even number divided by two
|
|
let reslen = (inlen + 2) >> 1;
|
|
let mut res = vec![];
|
|
res.reserve(reslen);
|
|
|
|
let first_byte = {
|
|
let mut bits = ((inlen as u8 & 1) + (2 * leaf as u8)) << 4;
|
|
if oddness_factor == 1 {
|
|
bits += nibbles[0];
|
|
}
|
|
bits
|
|
};
|
|
|
|
res.push(first_byte);
|
|
|
|
let mut offset = oddness_factor;
|
|
while offset < inlen {
|
|
let byte = (nibbles[offset] << 4) + nibbles[offset + 1];
|
|
res.push(byte);
|
|
offset += 2;
|
|
}
|
|
|
|
res
|
|
}
|
|
|
|
/// Converts slice of bytes to nibbles.
|
|
fn as_nibbles(bytes: &[u8]) -> Vec<u8> {
|
|
let mut res = vec![];
|
|
res.reserve(bytes.len() * 2);
|
|
for i in 0..bytes.len() {
|
|
res.push(bytes[i] >> 4);
|
|
res.push((bytes[i] << 4) >> 4);
|
|
}
|
|
res
|
|
}
|
|
|
|
fn hash256rlp(input: &[(Vec<u8>, Vec<u8>)], pre_len: usize, stream: &mut RlpStream) {
|
|
let inlen = input.len();
|
|
|
|
// in case of empty slice, just append empty data
|
|
if inlen == 0 {
|
|
stream.append_empty_data();
|
|
return;
|
|
}
|
|
|
|
// take slices
|
|
let key: &Vec<u8> = &input[0].0;
|
|
let value: &[u8] = &input[0].1;
|
|
|
|
// if the slice contains just one item, append the suffix of the key
|
|
// and then append value
|
|
if inlen == 1 {
|
|
stream.append_list(2);
|
|
stream.append(&hex_prefix_encode(&key[pre_len..], true));
|
|
stream.append(&value);
|
|
return;
|
|
}
|
|
|
|
// get length of the longest shared prefix in slice keys
|
|
let shared_prefix = input.iter()
|
|
// skip first element
|
|
.skip(1)
|
|
// get minimum number of shared nibbles between first and each successive
|
|
.fold(key.len(), | acc, &(ref k, _) | {
|
|
cmp::min(key.shared_prefix_len(&k), acc)
|
|
});
|
|
|
|
// if shared prefix is higher than current prefix append its
|
|
// new part of the key to the stream
|
|
// then recursively append suffixes of all items who had this key
|
|
if shared_prefix > pre_len {
|
|
stream.append_list(2);
|
|
stream.append(&hex_prefix_encode(&key[pre_len..shared_prefix], false));
|
|
hash256aux(input, shared_prefix, stream);
|
|
return;
|
|
}
|
|
|
|
// an item for every possible nibble/suffix
|
|
// + 1 for data
|
|
stream.append_list(17);
|
|
|
|
// if first key len is equal to prefix_len, move to next element
|
|
let mut begin = match pre_len == key.len() {
|
|
true => 1,
|
|
false => 0
|
|
};
|
|
|
|
// iterate over all possible nibbles
|
|
for i in 0..16 {
|
|
// cout how many successive elements have same next nibble
|
|
let len = match begin < input.len() {
|
|
true => input[begin..].iter()
|
|
.take_while(| pair | pair.0[pre_len] == i )
|
|
.count(),
|
|
false => 0
|
|
};
|
|
|
|
// if at least 1 successive element has the same nibble
|
|
// append their suffixes
|
|
match len {
|
|
0 => { stream.append_empty_data(); },
|
|
_ => hash256aux(&input[begin..(begin + len)], pre_len + 1, stream)
|
|
}
|
|
begin += len;
|
|
}
|
|
|
|
// if fist key len is equal prefix, append it's value
|
|
match pre_len == key.len() {
|
|
true => { stream.append(&value); },
|
|
false => { stream.append_empty_data(); }
|
|
};
|
|
}
|
|
|
|
fn hash256aux(input: &[(Vec<u8>, Vec<u8>)], pre_len: usize, stream: &mut RlpStream) {
|
|
let mut s = RlpStream::new();
|
|
hash256rlp(input, pre_len, &mut s);
|
|
let out = s.out();
|
|
match out.len() {
|
|
0...31 => stream.append_raw(&out, 1),
|
|
_ => stream.append(&out.sha3())
|
|
};
|
|
}
|
|
|
|
|
|
#[test]
|
|
fn test_nibbles() {
|
|
let v = vec![0x31, 0x23, 0x45];
|
|
let e = vec![3, 1, 2, 3, 4, 5];
|
|
assert_eq!(as_nibbles(&v), e);
|
|
|
|
// A => 65 => 0x41 => [4, 1]
|
|
let v: Vec<u8> = From::from("A");
|
|
let e = vec![4, 1];
|
|
assert_eq!(as_nibbles(&v), e);
|
|
}
|
|
|
|
#[test]
|
|
fn test_hex_prefix_encode() {
|
|
let v = vec![0, 0, 1, 2, 3, 4, 5];
|
|
let e = vec![0x10, 0x01, 0x23, 0x45];
|
|
let h = hex_prefix_encode(&v, false);
|
|
assert_eq!(h, e);
|
|
|
|
let v = vec![0, 1, 2, 3, 4, 5];
|
|
let e = vec![0x00, 0x01, 0x23, 0x45];
|
|
let h = hex_prefix_encode(&v, false);
|
|
assert_eq!(h, e);
|
|
|
|
let v = vec![0, 1, 2, 3, 4, 5];
|
|
let e = vec![0x20, 0x01, 0x23, 0x45];
|
|
let h = hex_prefix_encode(&v, true);
|
|
assert_eq!(h, e);
|
|
|
|
let v = vec![1, 2, 3, 4, 5];
|
|
let e = vec![0x31, 0x23, 0x45];
|
|
let h = hex_prefix_encode(&v, true);
|
|
assert_eq!(h, e);
|
|
|
|
let v = vec![1, 2, 3, 4];
|
|
let e = vec![0x00, 0x12, 0x34];
|
|
let h = hex_prefix_encode(&v, false);
|
|
assert_eq!(h, e);
|
|
|
|
let v = vec![4, 1];
|
|
let e = vec![0x20, 0x41];
|
|
let h = hex_prefix_encode(&v, true);
|
|
assert_eq!(h, e);
|
|
}
|
|
|
|
#[cfg(test)]
|
|
mod tests {
|
|
extern crate json_tests;
|
|
use self::json_tests::*;
|
|
use hash::*;
|
|
use triehash::*;
|
|
|
|
#[test]
|
|
fn test_triehash_out_of_order() {
|
|
assert!(trie_root(vec![
|
|
(vec![0x01u8, 0x23], vec![0x01u8, 0x23]),
|
|
(vec![0x81u8, 0x23], vec![0x81u8, 0x23]),
|
|
(vec![0xf1u8, 0x23], vec![0xf1u8, 0x23]),
|
|
]) ==
|
|
trie_root(vec![
|
|
(vec![0x01u8, 0x23], vec![0x01u8, 0x23]),
|
|
(vec![0xf1u8, 0x23], vec![0xf1u8, 0x23]),
|
|
(vec![0x81u8, 0x23], vec![0x81u8, 0x23]),
|
|
]));
|
|
}
|
|
|
|
#[test]
|
|
fn test_triehash_json() {
|
|
execute_tests_from_directory::<trie::TriehashTest, _>("json-tests/json/trie/*.json", &mut | file, input, output | {
|
|
println!("file: {}, output: {:?}", file, output);
|
|
assert_eq!(trie_root(input), H256::from_slice(&output));
|
|
});
|
|
}
|
|
}
|
|
|