use std::{mem, str};
use std::iter::{once, empty};
use byteorder::{ByteOrder, BigEndian};
use traits::{Encodable, Decodable};
use stream::RlpStream;
use {Rlp, DecoderError};
pub fn decode_usize(bytes: &[u8]) -> Result<usize, DecoderError> {
match bytes.len() {
l if l <= mem::size_of::<usize>() => {
if bytes[0] == 0 {
return Err(DecoderError::RlpInvalidIndirection);
}
let mut res = 0usize;
for i in 0..l {
let shift = (l - 1 - i) * 8;
res = res + ((bytes[i] as usize) << shift);
}
Ok(res)
}
_ => Err(DecoderError::RlpIsTooBig),
}
}
impl Encodable for bool {
fn rlp_append(&self, s: &mut RlpStream) {
s.encoder().encode_iter(once(if *self { 1u8 } else { 0 }));
}
}
impl Decodable for bool {
fn decode(rlp: &Rlp) -> Result<Self, DecoderError> {
rlp.decoder().decode_value(|bytes| {
match bytes.len() {
0 => Ok(false),
1 => Ok(bytes[0] != 0),
_ => Err(DecoderError::RlpIsTooBig),
}
})
}
}
impl<'a> Encodable for &'a [u8] {
fn rlp_append(&self, s: &mut RlpStream) {
s.encoder().encode_value(self);
}
}
impl Encodable for Vec<u8> {
fn rlp_append(&self, s: &mut RlpStream) {
s.encoder().encode_value(self);
}
}
impl Decodable for Vec<u8> {
fn decode(rlp: &Rlp) -> Result<Self, DecoderError> {
rlp.decoder().decode_value(|bytes| {
Ok(bytes.to_vec())
})
}
}
impl<T> Encodable for Option<T> where T: Encodable {
fn rlp_append(&self, s: &mut RlpStream) {
match *self {
None => {
s.begin_list(0);
},
Some(ref value) => {
s.begin_list(1);
s.append(value);
}
}
}
}
impl<T> Decodable for Option<T> where T: Decodable {
fn decode(rlp: &Rlp) -> Result<Self, DecoderError> {
let items = rlp.item_count()?;
match items {
1 => rlp.val_at(0).map(Some),
0 => Ok(None),
_ => Err(DecoderError::RlpIncorrectListLen),
}
}
}
impl Encodable for u8 {
fn rlp_append(&self, s: &mut RlpStream) {
if *self != 0 {
s.encoder().encode_iter(once(*self));
} else {
s.encoder().encode_iter(empty());
}
}
}
impl Decodable for u8 {
fn decode(rlp: &Rlp) -> Result<Self, DecoderError> {
rlp.decoder().decode_value(|bytes| {
match bytes.len() {
1 if bytes[0] != 0 => Ok(bytes[0]),
0 => Ok(0),
1 => Err(DecoderError::RlpInvalidIndirection),
_ => Err(DecoderError::RlpIsTooBig),
}
})
}
}
macro_rules! impl_encodable_for_u {
($name: ident, $func: ident, $size: expr) => {
impl Encodable for $name {
fn rlp_append(&self, s: &mut RlpStream) {
let leading_empty_bytes = self.leading_zeros() as usize / 8;
let mut buffer = [0u8; $size];
BigEndian::$func(&mut buffer, *self);
s.encoder().encode_value(&buffer[leading_empty_bytes..]);
}
}
}
}
macro_rules! impl_decodable_for_u {
($name: ident) => {
impl Decodable for $name {
fn decode(rlp: &Rlp) -> Result<Self, DecoderError> {
rlp.decoder().decode_value(|bytes| {
match bytes.len() {
0 | 1 => u8::decode(rlp).map(|v| v as $name),
l if l <= mem::size_of::<$name>() => {
if bytes[0] == 0 {
return Err(DecoderError::RlpInvalidIndirection);
}
let mut res = 0 as $name;
for i in 0..l {
let shift = (l - 1 - i) * 8;
res = res + ((bytes[i] as $name) << shift);
}
Ok(res)
}
_ => Err(DecoderError::RlpIsTooBig),
}
})
}
}
}
}
impl_encodable_for_u!(u16, write_u16, 2);
impl_encodable_for_u!(u32, write_u32, 4);
impl_encodable_for_u!(u64, write_u64, 8);
impl_decodable_for_u!(u16);
impl_decodable_for_u!(u32);
impl_decodable_for_u!(u64);
impl Encodable for usize {
fn rlp_append(&self, s: &mut RlpStream) {
(*self as u64).rlp_append(s);
}
}
impl Decodable for usize {
fn decode(rlp: &Rlp) -> Result<Self, DecoderError> {
u64::decode(rlp).map(|value| value as usize)
}
}
#[cfg(feature = "ethereum")]
mod ethereum_traits {
use super::*;
use std::cmp;
use ethereum_types::{U128, U256, H64, H128, H160, H256, H512, H520, Bloom};
macro_rules! impl_encodable_for_hash {
($name: ident) => {
impl Encodable for $name {
fn rlp_append(&self, s: &mut RlpStream) {
s.encoder().encode_value(self);
}
}
}
}
macro_rules! impl_decodable_for_hash {
($name: ident, $size: expr) => {
impl Decodable for $name {
fn decode(rlp: &Rlp) -> Result<Self, DecoderError> {
rlp.decoder().decode_value(|bytes| match bytes.len().cmp(&$size) {
cmp::Ordering::Less => Err(DecoderError::RlpIsTooShort),
cmp::Ordering::Greater => Err(DecoderError::RlpIsTooBig),
cmp::Ordering::Equal => {
let mut t = [0u8; $size];
t.copy_from_slice(bytes);
Ok($name(t))
}
})
}
}
}
}
macro_rules! impl_encodable_for_uint {
($name: ident, $size: expr) => {
impl Encodable for $name {
fn rlp_append(&self, s: &mut RlpStream) {
let leading_empty_bytes = $size - (self.bits() + 7) / 8;
let mut buffer = [0u8; $size];
self.to_big_endian(&mut buffer);
s.encoder().encode_value(&buffer[leading_empty_bytes..]);
}
}
}
}
macro_rules! impl_decodable_for_uint {
($name: ident, $size: expr) => {
impl Decodable for $name {
fn decode(rlp: &Rlp) -> Result<Self, DecoderError> {
rlp.decoder().decode_value(|bytes| {
if !bytes.is_empty() && bytes[0] == 0 {
Err(DecoderError::RlpInvalidIndirection)
} else if bytes.len() <= $size {
Ok($name::from(bytes))
} else {
Err(DecoderError::RlpIsTooBig)
}
})
}
}
}
}
impl_encodable_for_hash!(H64);
impl_encodable_for_hash!(H128);
impl_encodable_for_hash!(H160);
impl_encodable_for_hash!(H256);
impl_encodable_for_hash!(H512);
impl_encodable_for_hash!(H520);
impl_encodable_for_hash!(Bloom);
impl_decodable_for_hash!(H64, 8);
impl_decodable_for_hash!(H128, 16);
impl_decodable_for_hash!(H160, 20);
impl_decodable_for_hash!(H256, 32);
impl_decodable_for_hash!(H512, 64);
impl_decodable_for_hash!(H520, 65);
impl_decodable_for_hash!(Bloom, 256);
impl_encodable_for_uint!(U256, 32);
impl_encodable_for_uint!(U128, 16);
impl_decodable_for_uint!(U256, 32);
impl_decodable_for_uint!(U128, 16);
}
impl<'a> Encodable for &'a str {
fn rlp_append(&self, s: &mut RlpStream) {
s.encoder().encode_value(self.as_bytes());
}
}
impl Encodable for String {
fn rlp_append(&self, s: &mut RlpStream) {
s.encoder().encode_value(self.as_bytes());
}
}
impl Decodable for String {
fn decode(rlp: &Rlp) -> Result<Self, DecoderError> {
rlp.decoder().decode_value(|bytes| {
match str::from_utf8(bytes) {
Ok(s) => Ok(s.to_owned()),
Err(_err) => Err(DecoderError::RlpExpectedToBeData),
}
})
}
}