lighthouse/ssz/src/impls.rs
2018-09-11 12:25:49 +02:00

84 lines
2.1 KiB
Rust

/*
* Implementations for various types
*/
use super::{
DecodeError,
Decodable,
Encodable,
SszStream
};
use super::bytes::{ BytesMut, BufMut };
use super::ethereum_types::{ H256, U256 };
macro_rules! impl_decodable_for_uint {
($type: ident, $bit_size: expr) => {
impl Decodable for $type {
fn ssz_decode(bytes: &[u8])
-> Result<Self, DecodeError>
{
assert!(0 < $bit_size &&
$bit_size <= 64 &&
$bit_size % 8 == 0);
let bytes_required = $bit_size / 8;
if bytes_required <= bytes.len() {
let mut result = 0;
for i in 0..bytes.len() {
let offset = (bytes.len() - i - 1) * 8;
result = (bytes[i] << offset) | result;
};
Ok(result.into())
} else {
Err(DecodeError::TooLong)
}
}
}
}
}
impl_decodable_for_uint!(u64, 64 / 8);
impl_decodable_for_uint!(u16, 16 / 8);
impl Encodable for u8 {
fn ssz_append(&self, s: &mut SszStream) {
s.extend_buffer(&mut vec![*self]);
}
}
impl Encodable for u16 {
fn ssz_append(&self, s: &mut SszStream) {
let mut buf = BytesMut::with_capacity(16/8);
buf.put_u16_be(*self);
s.extend_buffer(&buf.to_vec());
}
}
impl Encodable for u32 {
fn ssz_append(&self, s: &mut SszStream) {
let mut buf = BytesMut::with_capacity(32/8);
buf.put_u32_be(*self);
s.extend_buffer(&buf.to_vec());
}
}
impl Encodable for u64 {
fn ssz_append(&self, s: &mut SszStream) {
let mut buf = BytesMut::with_capacity(64/8);
buf.put_u64_be(*self);
s.extend_buffer(&buf.to_vec());
}
}
impl Encodable for H256 {
fn ssz_append(&self, s: &mut SszStream) {
s.extend_buffer(&self.to_vec());
}
}
impl Encodable for U256 {
fn ssz_append(&self, s: &mut SszStream) {
let mut a = [0; 32];
self.to_big_endian(&mut a);
s.append_encoded_array(&mut a);
}
}