Implement ssz length decoding
This commit is contained in:
parent
0566d18153
commit
fe95a0cce2
@ -22,6 +22,11 @@ pub struct SszStream {
|
||||
buffer: Vec<u8>
|
||||
}
|
||||
|
||||
#[derive(Debug)]
|
||||
pub enum DecodeError {
|
||||
TooShort,
|
||||
}
|
||||
|
||||
impl SszStream {
|
||||
/// Create a new, empty steam for writing ssz values.
|
||||
pub fn new() -> Self {
|
||||
@ -79,6 +84,20 @@ fn encode_length(len: usize, length_bytes: usize) -> Vec<u8> {
|
||||
header
|
||||
}
|
||||
|
||||
fn decode_length(bytes: &Vec<u8>, length_bytes: usize)
|
||||
-> Result<usize, DecodeError>
|
||||
{
|
||||
if bytes.len() < length_bytes {
|
||||
return Err(DecodeError::TooShort);
|
||||
};
|
||||
let mut len: usize = 0;
|
||||
for i in 0..length_bytes {
|
||||
let offset = (length_bytes - i - 1) * 8;
|
||||
len = ((bytes[i] as usize) << offset) | len;
|
||||
};
|
||||
Ok(len)
|
||||
}
|
||||
|
||||
|
||||
#[cfg(test)]
|
||||
mod tests {
|
||||
@ -121,6 +140,45 @@ mod tests {
|
||||
encode_length(4294967296, 4); // 2^(4*8)
|
||||
}
|
||||
|
||||
#[test]
|
||||
fn test_decode_length() {
|
||||
let decoded = decode_length(
|
||||
&vec![0, 0, 0, 1],
|
||||
LENGTH_BYTES);
|
||||
assert_eq!(decoded.unwrap(), 1);
|
||||
|
||||
let decoded = decode_length(
|
||||
&vec![0, 0, 1, 0],
|
||||
LENGTH_BYTES);
|
||||
assert_eq!(decoded.unwrap(), 256);
|
||||
}
|
||||
|
||||
#[test]
|
||||
fn test_encode_decode_length() {
|
||||
let params: Vec<usize> = vec![
|
||||
0,
|
||||
1,
|
||||
2,
|
||||
3,
|
||||
7,
|
||||
8,
|
||||
16,
|
||||
2^8,
|
||||
2^8 + 1,
|
||||
2^16,
|
||||
2^16 + 1,
|
||||
2^24,
|
||||
2^24 + 1,
|
||||
2^32,
|
||||
];
|
||||
for i in params {
|
||||
let decoded = decode_length(
|
||||
&encode_length(i, LENGTH_BYTES),
|
||||
LENGTH_BYTES).unwrap();
|
||||
assert_eq!(i, decoded);
|
||||
}
|
||||
}
|
||||
|
||||
#[test]
|
||||
fn test_serialization() {
|
||||
pub struct TestStruct {
|
||||
|
Loading…
Reference in New Issue
Block a user