use super::BranchNodeCompact;
use bytes::Buf;
use reth_codecs::Compact;
#[derive(Debug, Clone, PartialEq, Eq, Default)]
pub struct StoredSubNode {
pub key: Vec<u8>,
pub nibble: Option<u8>,
pub node: Option<BranchNodeCompact>,
}
impl Compact for StoredSubNode {
fn to_compact<B>(&self, buf: &mut B) -> usize
where
B: bytes::BufMut + AsMut<[u8]>,
{
let mut len = 0;
buf.put_u16(self.key.len() as u16);
buf.put_slice(&self.key[..]);
len += 2 + self.key.len();
if let Some(nibble) = self.nibble {
buf.put_u8(1);
buf.put_u8(nibble);
len += 2;
} else {
buf.put_u8(0);
len += 1;
}
if let Some(node) = &self.node {
buf.put_u8(1);
len += 1;
len += node.to_compact(buf);
} else {
len += 1;
buf.put_u8(0);
}
len
}
fn from_compact(mut buf: &[u8], _len: usize) -> (Self, &[u8]) {
let key_len = buf.get_u16() as usize;
let key = Vec::from(&buf[..key_len]);
buf.advance(key_len);
let nibbles_exists = buf.get_u8() != 0;
let nibble = if nibbles_exists { Some(buf.get_u8()) } else { None };
let node_exists = buf.get_u8() != 0;
let node = if node_exists {
let (node, rest) = BranchNodeCompact::from_compact(buf, 0);
buf = rest;
Some(node)
} else {
None
};
(Self { key, nibble, node }, buf)
}
}
#[cfg(test)]
mod tests {
use super::*;
use crate::TrieMask;
use alloy_primitives::B256;
#[test]
fn subnode_roundtrip() {
let subnode = StoredSubNode {
key: vec![],
nibble: None,
node: Some(BranchNodeCompact {
state_mask: TrieMask::new(1),
tree_mask: TrieMask::new(0),
hash_mask: TrieMask::new(1),
hashes: vec![B256::ZERO],
root_hash: None,
}),
};
let mut encoded = vec![];
subnode.to_compact(&mut encoded);
let (decoded, _) = StoredSubNode::from_compact(&encoded[..], 0);
assert_eq!(subnode, decoded);
}
}