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triehash clenaup in progress

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debris 2015-11-30 01:19:04 +01:00
parent f02bd0cd17
commit 710d3594a8
1 changed files with 59 additions and 47 deletions
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106
src/triehash.rs
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@ -139,7 +139,7 @@ impl NibblePair {
}
}
fn shared_nibble_prefix_len(vec: &[NibblePair]) -> usize {
fn nibble_shared_prefix_len(vec: &[NibblePair]) -> usize {
if vec.len() == 0 {
return 0;
}
@ -185,54 +185,66 @@ pub fn hash256(vec: &[NibblePair]) -> H256 {
}
fn hash256rlp(vec: &[NibblePair], pre_len: usize, stream: &mut RlpStream) {
match vec.len() {
0 => {
stream.append(&"");
},
1 => {
stream.append_list(2);
stream.append(&hex_prefix_encode(&vec[0].nibble[pre_len..], true));
stream.append(&vec[0].data);
},
_ => {
let shared_prefix = shared_nibble_prefix_len(vec);
let vlen = vec.len();
match shared_prefix > pre_len {
true => {
stream.append_list(2);
stream.append(&hex_prefix_encode(&vec[0].nibble[pre_len..shared_prefix], false));
hash256aux(vec, shared_prefix, stream);
},
false => {
stream.append_list(17);
// in case of empty slice, just append null
if vlen == 0 {
stream.append(&"");
return;
}
// if first nibble len is equal to pre_len
// move forward
let mut begin = match pre_len == vec[0].nibble.len() {
true => 1,
false => 0
};
// if the slice contains just one item, append the suffix of the key
// and then append value
if vlen == 1 {
stream.append_list(2);
stream.append(&hex_prefix_encode(&vec[0].nibble[pre_len..], true));
stream.append(&vec[0].data);
return;
}
for i in 0..16 {
// cout how many successive elements have same next nibble
let len = vec[begin..].iter()
.map(| pair | pair.nibble[pre_len] )
.take_while(|&q| q == i).count();
match len {
0 => { stream.append(&""); },
_ => hash256aux(&vec[begin..(begin + len)], pre_len + 1, stream)
}
begin += len;
}
// get length of the longest shared prefix in slice keys
let shared_prefix = nibble_shared_prefix_len(vec);
match pre_len == vec[0].nibble.len() {
true => { stream.append(&vec[0].data); } ,
false => { stream.append(&""); }
};
}
}
// 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(&vec[0].nibble[pre_len..shared_prefix], false));
hash256aux(vec, 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 == vec[0].nibble.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 = vec[begin..].iter()
.map(| pair | pair.nibble[pre_len] )
.take_while(|&q| q == i).count();
// if at least 1 successive element has the same nibble
// append their suffixes
match len {
0 => { stream.append(&""); },
_ => hash256aux(&vec[begin..(begin + len)], pre_len + 1, stream)
}
begin += len;
}
// if fist key len is equal prefix, append it's value
match pre_len == vec[0].nibble.len() {
true => { stream.append(&vec[0].data); },
false => { stream.append(&""); }
};
}
@ -249,7 +261,7 @@ fn hash256aux(vec: &[NibblePair], pre_len: usize, stream: &mut RlpStream) {
#[test]
fn test_shared_nibble_len() {
let len = shared_nibble_prefix_len(&vec![
let len = nibble_shared_prefix_len(&vec![
NibblePair::new(vec![0, 1, 2, 3, 4, 5, 6], vec![]),
NibblePair::new(vec![0, 1, 2, 3, 4, 5, 6], vec![]),
]);
@ -259,7 +271,7 @@ fn test_shared_nibble_len() {
#[test]
fn test_shared_nibble_len2() {
let len = shared_nibble_prefix_len(&vec![
let len = nibble_shared_prefix_len(&vec![
NibblePair::new(vec![0, 1, 2, 3, 4, 5, 6], vec![]),
NibblePair::new(vec![0, 1, 2, 3, 4, 5, 6], vec![]),
NibblePair::new(vec![4, 1, 2, 3, 4, 5, 6], vec![])
@ -270,7 +282,7 @@ fn test_shared_nibble_len2() {
#[test]
fn test_shared_nibble_len3() {
let len = shared_nibble_prefix_len(&vec![
let len = nibble_shared_prefix_len(&vec![
NibblePair::new(vec![0, 1, 2, 3, 4, 5, 6], vec![]),
NibblePair::new(vec![0, 1, 2, 3, 4, 5, 6], vec![]),
NibblePair::new(vec![0, 1, 2, 4, 4, 5, 6], vec![])