openethereum/src/rlp.rs
2015-12-01 03:35:55 +01:00

1490 lines
37 KiB
Rust

//! Rlp serialization module
//!
//! Allows encoding, decoding, and view onto rlp-slice
//!
//!# What should you use when?
//!
//!### Use `encode` function when:
//! * You want to encode something inline.
//! * You do not work on big set of data.
//! * You want to encode whole data structure at once.
//!
//!### Use `decode` function when:
//! * You want to decode something inline.
//! * You do not work on big set of data.
//! * You want to decode whole rlp at once.
//!
//!### Use `RlpStream` when:
//! * You want to encode something in portions.
//! * You encode a big set of data.
//!
//!### Use `Rlp` when:
//! * You are working on trusted data (not corrupted).
//! * You want to get view onto rlp-slice.
//! * You don't want to decode whole rlp at once.
//!
//!### Use `UntrustedRlp` when:
//! * You are working on untrusted data (~corrupted).
//! * You need to handle data corruption errors.
//! * You are working on input data.
//! * You want to get view onto rlp-slice.
//! * You don't want to decode whole rlp at once.
use std::fmt;
use std::cell::Cell;
use std::collections::LinkedList;
use std::error::Error as StdError;
use bytes::{ToBytes, FromBytes, FromBytesError};
use vector::InsertSlice;
/// Data-oriented view onto rlp-slice.
///
/// This is immutable structere. No operations change it.
///
/// Should be used in places where, error handling is required,
/// eg. on input
#[derive(Debug)]
pub struct UntrustedRlp<'a> {
bytes: &'a [u8],
cache: Cell<OffsetCache>,
}
/// rlp offset
#[derive(Copy, Clone, Debug)]
struct OffsetCache {
index: usize,
offset: usize,
}
impl OffsetCache {
fn new(index: usize, offset: usize) -> OffsetCache {
OffsetCache {
index: index,
offset: offset,
}
}
}
/// stores basic information about item
struct ItemInfo {
prefix_len: usize,
value_len: usize,
}
impl ItemInfo {
fn new(prefix_len: usize, value_len: usize) -> ItemInfo {
ItemInfo {
prefix_len: prefix_len,
value_len: value_len,
}
}
}
#[derive(Debug, PartialEq, Eq)]
pub enum DecoderError {
FromBytesError(FromBytesError),
RlpIsTooShort,
RlpExpectedToBeList,
RlpExpectedToBeData,
BadRlp,
}
impl StdError for DecoderError {
fn description(&self) -> &str {
"builder error"
}
}
impl fmt::Display for DecoderError {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
fmt::Debug::fmt(&self, f)
}
}
impl From<FromBytesError> for DecoderError {
fn from(err: FromBytesError) -> DecoderError {
DecoderError::FromBytesError(err)
}
}
/// Data-oriented view onto trusted rlp-slice.
///
/// Unlikely to `UntrustedRlp` doesn't bother you with error
/// handling. It assumes that you know what you are doing.
pub struct Rlp<'a> {
rlp: UntrustedRlp<'a>
}
impl<'a> From<UntrustedRlp<'a>> for Rlp<'a> {
fn from(rlp: UntrustedRlp<'a>) -> Rlp<'a> {
Rlp { rlp: rlp }
}
}
impl<'a> From<Rlp<'a>> for UntrustedRlp<'a> {
fn from(unsafe_rlp: Rlp<'a>) -> UntrustedRlp<'a> {
unsafe_rlp.rlp
}
}
pub enum Prototype {
Null,
Data(usize),
List(usize),
}
impl<'a, 'view> Rlp<'a> where 'a: 'view {
/// Create a new instance of `Rlp`
pub fn new(bytes: &'a [u8]) -> Rlp<'a> {
Rlp {
rlp: UntrustedRlp::new(bytes)
}
}
/// Get the prototype of the RLP.
pub fn prototype(&self) -> Prototype {
if self.is_data() {
Prototype::Data(self.size())
}
else if self.is_list() {
Prototype::List(self.item_count())
}
else {
Prototype::Null
}
}
/// The raw data of the RLP.
///
/// ```rust
/// extern crate ethcore_util as util;
/// use util::rlp::*;
///
/// fn main () {
/// let data = vec![0xc8, 0x83, b'c', b'a', b't', 0x83, b'd', b'o', b'g'];
/// let rlp = Rlp::new(&data);
/// let dog = rlp.at(1).raw();
/// assert_eq!(dog, &[0x83, b'd', b'o', b'g']);
/// }
/// ```
pub fn raw(&'view self) -> &'a [u8] {
self.rlp.raw()
}
pub fn data(&'view self) -> &'a [u8] {
self.rlp.data()
}
/// Returns number of RLP items.
///
/// ```rust
/// extern crate ethcore_util as util;
/// use util::rlp::*;
///
/// fn main () {
/// let data = vec![0xc8, 0x83, b'c', b'a', b't', 0x83, b'd', b'o', b'g'];
/// let rlp = Rlp::new(&data);
/// assert_eq!(rlp.item_count(), 2);
/// let view = rlp.at(1);
/// assert_eq!(view.item_count(), 0);
/// }
/// ```
pub fn item_count(&self) -> usize {
self.rlp.item_count()
}
/// Returns the number of bytes in the data, or zero if it isn't data.
///
/// ```rust
/// extern crate ethcore_util as util;
/// use util::rlp::*;
///
/// fn main () {
/// let data = vec![0xc8, 0x83, b'c', b'a', b't', 0x83, b'd', b'o', b'g'];
/// let rlp = Rlp::new(&data);
/// assert_eq!(rlp.size(), 0);
/// let view = rlp.at(1);
/// assert_eq!(view.size(), 3);
/// }
/// ```
pub fn size(&self) -> usize {
self.rlp.size()
}
/// Get view onto RLP-slice at index.
///
/// Caches offset to given index, so access to successive
/// slices is faster.
///
/// ```rust
/// extern crate ethcore_util as util;
/// use util::rlp::*;
///
/// fn main () {
/// let data = vec![0xc8, 0x83, b'c', b'a', b't', 0x83, b'd', b'o', b'g'];
/// let rlp = Rlp::new(&data);
/// let dog = String::decode(&rlp.at(1));
/// assert_eq!(dog, "dog".to_string());
/// }
/// ```
pub fn at(&'view self, index: usize) -> Rlp<'a> {
From::from(self.rlp.at(index).unwrap())
}
/// No value
///
/// ```rust
/// extern crate ethcore_util as util;
/// use util::rlp::*;
///
/// fn main () {
/// let data = vec![];
/// let rlp = Rlp::new(&data);
/// assert!(rlp.is_null());
/// }
/// ```
pub fn is_null(&self) -> bool {
self.rlp.is_null()
}
/// Contains a zero-length string or zero-length list.
///
/// ```rust
/// extern crate ethcore_util as util;
/// use util::rlp::*;
///
/// fn main () {
/// let data = vec![0xc0];
/// let rlp = Rlp::new(&data);
/// assert!(rlp.is_empty());
/// }
/// ```
pub fn is_empty(&self) -> bool {
self.rlp.is_empty()
}
/// List value
///
/// ```rust
/// extern crate ethcore_util as util;
/// use util::rlp::*;
///
/// fn main () {
/// let data = vec![0xc8, 0x83, b'c', b'a', b't', 0x83, b'd', b'o', b'g'];
/// let rlp = Rlp::new(&data);
/// assert!(rlp.is_list());
/// }
/// ```
pub fn is_list(&self) -> bool {
self.rlp.is_list()
}
/// String value
///
/// ```rust
/// extern crate ethcore_util as util;
/// use util::rlp::*;
///
/// fn main () {
/// let data = vec![0xc8, 0x83, b'c', b'a', b't', 0x83, b'd', b'o', b'g'];
/// let rlp = Rlp::new(&data);
/// assert!(rlp.at(1).is_data());
/// }
/// ```
pub fn is_data(&self) -> bool {
self.rlp.is_data()
}
/// Int value
///
/// ```rust
/// extern crate ethcore_util as util;
/// use util::rlp::*;
///
/// fn main () {
/// let data = vec![0xc1, 0x10];
/// let rlp = Rlp::new(&data);
/// assert_eq!(rlp.is_int(), false);
/// assert_eq!(rlp.at(0).is_int(), true);
/// }
/// ```
pub fn is_int(&self) -> bool {
self.rlp.is_int()
}
/// Get iterator over rlp-slices
///
/// ```rust
/// extern crate ethcore_util as util;
/// use util::rlp::*;
///
/// fn main () {
/// let data = vec![0xc8, 0x83, b'c', b'a', b't', 0x83, b'd', b'o', b'g'];
/// let rlp = Rlp::new(&data);
/// let strings: Vec<String> = rlp.iter().map(| i | String::decode(&i)).collect();
/// }
/// ```
pub fn iter(&'a self) -> RlpIterator<'a> {
self.into_iter()
}
}
impl<'a, 'view> UntrustedRlp<'a> where 'a: 'view {
/// returns new instance of `UntrustedRlp`
pub fn new(bytes: &'a [u8]) -> UntrustedRlp<'a> {
UntrustedRlp {
bytes: bytes,
cache: Cell::new(OffsetCache::new(usize::max_value(), 0)),
}
}
/// The bare data of the RLP.
///
/// ```rust
/// extern crate ethcore_util as util;
/// use util::rlp::*;
///
/// fn main () {
/// let data = vec![0xc8, 0x83, b'c', b'a', b't', 0x83, b'd', b'o', b'g'];
/// let rlp = UntrustedRlp::new(&data);
/// let dog = rlp.at(1).unwrap().raw();
/// assert_eq!(dog, &[0x83, b'd', b'o', b'g']);
/// }
/// ```
pub fn raw(&'view self) -> &'a [u8] {
self.bytes
}
pub fn data(&'view self) -> &'a [u8] {
let ii = Self::item_info(self.bytes).unwrap();
&self.bytes[ii.prefix_len..(ii.prefix_len + ii.value_len)]
}
/// Returns number of rlp items.
///
/// ```rust
/// extern crate ethcore_util as util;
/// use util::rlp::*;
///
/// fn main () {
/// let data = vec![0xc8, 0x83, b'c', b'a', b't', 0x83, b'd', b'o', b'g'];
/// let rlp = UntrustedRlp::new(&data);
/// assert_eq!(rlp.item_count(), 2);
/// let view = rlp.at(1).unwrap();
/// assert_eq!(view.item_count(), 0);
/// }
/// ```
pub fn item_count(&self) -> usize {
match self.is_list() {
true => self.iter().count(),
false => 0
}
}
/// Returns the number of bytes in the data, or zero if it isn't data.
///
/// ```rust
/// extern crate ethcore_util as util;
/// use util::rlp::*;
///
/// fn main () {
/// let data = vec![0xc8, 0x83, b'c', b'a', b't', 0x83, b'd', b'o', b'g'];
/// let rlp = UntrustedRlp::new(&data);
/// assert_eq!(rlp.size(), 0);
/// let view = rlp.at(1).unwrap();
/// assert_eq!(view.size(), 3);
/// }
/// ```
pub fn size(&self) -> usize {
match self.is_data() {
true => Self::item_info(self.bytes).unwrap().value_len,
false => 0
}
}
/// Get view onto rlp-slice at index
///
/// Caches offset to given index, so access to successive
/// slices is faster.
///
/// ```rust
/// extern crate ethcore_util as util;
/// use util::rlp::*;
///
/// fn main () {
/// let data = vec![0xc8, 0x83, b'c', b'a', b't', 0x83, b'd', b'o', b'g'];
/// let rlp = UntrustedRlp::new(&data);
/// let dog = String::decode_untrusted(&rlp.at(1).unwrap()).unwrap();
/// assert_eq!(dog, "dog".to_string());
/// }
/// ```
pub fn at(&'view self, index: usize) -> Result<UntrustedRlp<'a>, DecoderError> {
if !self.is_list() {
return Err(DecoderError::RlpExpectedToBeList);
}
// move to cached position if it's index is less or equal to
// current search index, otherwise move to beginning of list
let c = self.cache.get();
let (mut bytes, to_skip) = match c.index <= index {
true => (try!(UntrustedRlp::consume(self.bytes, c.offset)), index - c.index),
false => (try!(self.consume_list_prefix()), index),
};
// skip up to x items
bytes = try!(UntrustedRlp::consume_items(bytes, to_skip));
// update the cache
self.cache.set(OffsetCache::new(index, self.bytes.len() - bytes.len()));
// construct new rlp
let found = try!(UntrustedRlp::item_info(bytes));
Ok(UntrustedRlp::new(&bytes[0..found.prefix_len + found.value_len]))
}
/// No value
///
/// ```rust
/// extern crate ethcore_util as util;
/// use util::rlp::*;
///
/// fn main () {
/// let data = vec![];
/// let rlp = UntrustedRlp::new(&data);
/// assert!(rlp.is_null());
/// }
/// ```
pub fn is_null(&self) -> bool {
self.bytes.len() == 0
}
/// Contains a zero-length string or zero-length list.
///
/// ```rust
/// extern crate ethcore_util as util;
/// use util::rlp::*;
///
/// fn main () {
/// let data = vec![0xc0];
/// let rlp = UntrustedRlp::new(&data);
/// assert!(rlp.is_empty());
/// }
/// ```
pub fn is_empty(&self) -> bool {
!self.is_null() && (self.bytes[0] == 0xc0 || self.bytes[0] == 0x80)
}
/// List value
///
/// ```rust
/// extern crate ethcore_util as util;
/// use util::rlp::*;
///
/// fn main () {
/// let data = vec![0xc8, 0x83, b'c', b'a', b't', 0x83, b'd', b'o', b'g'];
/// let rlp = UntrustedRlp::new(&data);
/// assert!(rlp.is_list());
/// }
/// ```
pub fn is_list(&self) -> bool {
!self.is_null() && self.bytes[0] >= 0xc0
}
/// String value
///
/// ```rust
/// extern crate ethcore_util as util;
/// use util::rlp::*;
///
/// fn main () {
/// let data = vec![0xc8, 0x83, b'c', b'a', b't', 0x83, b'd', b'o', b'g'];
/// let rlp = UntrustedRlp::new(&data);
/// assert!(rlp.at(1).unwrap().is_data());
/// }
/// ```
pub fn is_data(&self) -> bool {
!self.is_null() && self.bytes[0] < 0xc0
}
/// Int value
///
/// ```rust
/// extern crate ethcore_util as util;
/// use util::rlp::*;
///
/// fn main () {
/// let data = vec![0xc1, 0x10];
/// let rlp = UntrustedRlp::new(&data);
/// assert_eq!(rlp.is_int(), false);
/// assert_eq!(rlp.at(0).unwrap().is_int(), true);
/// }
/// ```
pub fn is_int(&self) -> bool {
if self.is_null() {
return false;
}
match self.bytes[0] {
0...0x80 => true,
0x81...0xb7 => self.bytes[1] != 0,
b @ 0xb8...0xbf => self.bytes[1 + b as usize - 0xb7] != 0,
_ => false
}
}
/// Get iterator over rlp-slices
///
/// ```rust
/// extern crate ethcore_util as util;
/// use util::rlp::*;
///
/// fn main () {
/// let data = vec![0xc8, 0x83, b'c', b'a', b't', 0x83, b'd', b'o', b'g'];
/// let rlp = UntrustedRlp::new(&data);
/// let strings: Vec<String> = rlp.iter()
/// .map(| i | String::decode_untrusted(&i))
/// .map(| s | s.unwrap())
/// .collect();
/// }
/// ```
pub fn iter(&'a self) -> UntrustedRlpIterator<'a> {
self.into_iter()
}
/// consumes first found prefix
fn consume_list_prefix(&self) -> Result<&'a [u8], DecoderError> {
let item = try!(UntrustedRlp::item_info(self.bytes));
let bytes = try!(UntrustedRlp::consume(self.bytes, item.prefix_len));
Ok(bytes)
}
/// consumes fixed number of items
fn consume_items(bytes: &'a [u8], items: usize) -> Result<&'a [u8], DecoderError> {
let mut result = bytes;
for _ in 0..items {
let i = try!(UntrustedRlp::item_info(result));
result = try!(UntrustedRlp::consume(result, (i.prefix_len + i.value_len)));
}
Ok(result)
}
/// return first item info
///
/// TODO: move this to decoder (?)
fn item_info(bytes: &[u8]) -> Result<ItemInfo, DecoderError> {
let item = match bytes.first().map(|&x| x) {
None => return Err(DecoderError::RlpIsTooShort),
Some(0...0x7f) => ItemInfo::new(0, 1),
Some(l @ 0x80...0xb7) => ItemInfo::new(1, l as usize - 0x80),
Some(l @ 0xb8...0xbf) => {
let len_of_len = l as usize - 0xb7;
let prefix_len = 1 + len_of_len;
let value_len = try!(usize::from_bytes(&bytes[1..prefix_len]));
ItemInfo::new(prefix_len, value_len)
}
Some(l @ 0xc0...0xf7) => ItemInfo::new(1, l as usize - 0xc0),
Some(l @ 0xf8...0xff) => {
let len_of_len = l as usize - 0xf7;
let prefix_len = 1 + len_of_len;
let value_len = try!(usize::from_bytes(&bytes[1..prefix_len]));
ItemInfo::new(prefix_len, value_len)
}
_ => return Err(DecoderError::BadRlp),
};
match item.prefix_len + item.value_len <= bytes.len() {
true => Ok(item),
false => Err(DecoderError::RlpIsTooShort),
}
}
/// consumes slice prefix of length `len`
fn consume(bytes: &'a [u8], len: usize) -> Result<&'a [u8], DecoderError> {
match bytes.len() >= len {
true => Ok(&bytes[len..]),
false => Err(DecoderError::RlpIsTooShort),
}
}
}
/// Iterator over rlp-slice list elements.
pub struct UntrustedRlpIterator<'a> {
rlp: &'a UntrustedRlp<'a>,
index: usize,
}
impl<'a> IntoIterator for &'a UntrustedRlp<'a> {
type Item = UntrustedRlp<'a>;
type IntoIter = UntrustedRlpIterator<'a>;
fn into_iter(self) -> Self::IntoIter {
UntrustedRlpIterator {
rlp: self,
index: 0,
}
}
}
impl<'a> Iterator for UntrustedRlpIterator<'a> {
type Item = UntrustedRlp<'a>;
fn next(&mut self) -> Option<UntrustedRlp<'a>> {
let index = self.index;
let result = self.rlp.at(index).ok();
self.index += 1;
result
}
}
/// Iterator over trusted rlp-slice list elements.
pub struct RlpIterator<'a> {
rlp: &'a Rlp<'a>,
index: usize
}
impl<'a> IntoIterator for &'a Rlp<'a> {
type Item = Rlp<'a>;
type IntoIter = RlpIterator<'a>;
fn into_iter(self) -> Self::IntoIter {
RlpIterator {
rlp: self,
index: 0,
}
}
}
impl<'a> Iterator for RlpIterator<'a> {
type Item = Rlp<'a>;
fn next(&mut self) -> Option<Rlp<'a>> {
let index = self.index;
let result = self.rlp.rlp.at(index).ok().map(| iter | { From::from(iter) });
self.index += 1;
result
}
}
/// Shortcut function to decode trusted rlp
///
/// ```rust
/// extern crate ethcore_util as util;
/// use util::rlp::*;
///
/// fn main () {
/// let data = vec![0xc8, 0x83, b'c', b'a', b't', 0x83, b'd', b'o', b'g'];
/// let animals: Vec<String> = decode(&data);
/// assert_eq!(animals, vec!["cat".to_string(), "dog".to_string()]);
/// }
/// ```
pub fn decode<T>(bytes: &[u8]) -> T where T: Decodable {
let rlp = Rlp::new(bytes);
T::decode(&rlp)
}
pub trait Decodable: Sized {
fn decode_untrusted(rlp: &UntrustedRlp) -> Result<Self, DecoderError>;
fn decode(rlp: &Rlp) -> Self {
Self::decode_untrusted(&rlp.rlp).unwrap()
}
}
impl<T> Decodable for T where T: FromBytes {
fn decode_untrusted(rlp: &UntrustedRlp) -> Result<Self, DecoderError> {
match rlp.is_data() {
true => BasicDecoder::read_value(rlp.bytes, | bytes | {
Ok(try!(T::from_bytes(bytes)))
}),
false => Err(DecoderError::RlpExpectedToBeData),
}
}
}
impl<T> Decodable for Vec<T> where T: Decodable {
fn decode_untrusted(rlp: &UntrustedRlp) -> Result<Self, DecoderError> {
match rlp.is_list() {
true => rlp.iter().map(|rlp| T::decode_untrusted(&rlp)).collect(),
false => Err(DecoderError::RlpExpectedToBeList),
}
}
}
impl Decodable for Vec<u8> {
fn decode_untrusted(rlp: &UntrustedRlp) -> Result<Self, DecoderError> {
match rlp.is_data() {
true => BasicDecoder::read_value(rlp.bytes, | bytes | {
let mut res = vec![];
res.extend(bytes);
Ok(res)
}),
false => Err(DecoderError::RlpExpectedToBeData),
}
}
}
pub trait Decoder {
fn read_value<T, F>(bytes: &[u8], f: F) -> Result<T, DecoderError> where F: FnOnce(&[u8]) -> Result<T, DecoderError>;
}
struct BasicDecoder;
impl Decoder for BasicDecoder {
fn read_value<T, F>(bytes: &[u8], f: F) -> Result<T, DecoderError> where F: FnOnce(&[u8]) -> Result<T, DecoderError> {
match bytes.first().map(|&x| x) {
// rlp is too short
None => Err(DecoderError::RlpIsTooShort),
// single byt value
Some(l @ 0...0x7f) => Ok(try!(f(&[l]))),
// 0-55 bytes
Some(l @ 0x80...0xb7) => Ok(try!(f(&bytes[1..(1 + l as usize - 0x80)]))),
// longer than 55 bytes
Some(l @ 0xb8...0xbf) => {
let len_of_len = l as usize - 0xb7;
let begin_of_value = 1 as usize + len_of_len;
let len = try!(usize::from_bytes(&bytes[1..begin_of_value]));
Ok(try!(f(&bytes[begin_of_value..begin_of_value + len])))
}
_ => Err(DecoderError::BadRlp),
}
}
}
#[derive(Debug)]
struct ListInfo {
position: usize,
current: usize,
max: usize,
}
impl ListInfo {
fn new(position: usize, max: usize) -> ListInfo {
ListInfo {
position: position,
current: 0,
max: max,
}
}
}
/// Appendable rlp encoder.
pub struct RlpStream {
unfinished_lists: LinkedList<ListInfo>,
encoder: BasicEncoder,
}
impl RlpStream {
/// Initializes instance of empty `RlpStream`.
pub fn new() -> RlpStream {
RlpStream {
unfinished_lists: LinkedList::new(),
encoder: BasicEncoder::new(),
}
}
/// Initializes the `RLPStream` as a list.
pub fn new_list(len: usize) -> RlpStream {
let mut stream = RlpStream::new();
stream.append_list(len);
stream
}
/// Apends value to the end of stream, chainable.
///
/// ```rust
/// extern crate ethcore_util as util;
/// use util::rlp::*;
///
/// fn main () {
/// let mut stream = RlpStream::new_list(2);
/// stream.append(&"cat").append(&"dog");
/// let out = stream.out();
/// assert_eq!(out, vec![0xc8, 0x83, b'c', b'a', b't', 0x83, b'd', b'o', b'g']);
/// }
/// ```
pub fn append<'a, E>(&'a mut self, object: &E) -> &'a mut RlpStream where E: Encodable + fmt::Debug {
// encode given value and add it at the end of the stream
object.encode(&mut self.encoder);
// if list is finished, prepend the length
self.note_appended(1);
// return chainable self
self
}
/// Declare appending the list of given size, chainable.
///
/// ```rust
/// extern crate ethcore_util as util;
/// use util::rlp::*;
///
/// fn main () {
/// let mut stream = RlpStream::new_list(2);
/// stream.append_list(2).append(&"cat").append(&"dog");
/// stream.append(&"");
/// let out = stream.out();
/// assert_eq!(out, vec![0xca, 0xc8, 0x83, b'c', b'a', b't', 0x83, b'd', b'o', b'g', 0x80]);
/// }
/// ```
pub fn append_list<'a>(&'a mut self, len: usize) -> &'a mut RlpStream {
// push new list
let position = self.encoder.bytes.len();
match len {
0 => {
// we may finish, if the appended list len is equal 0
self.encoder.bytes.push(0xc0u8);
self.note_appended(1);
}
_ => self.unfinished_lists.push_back(ListInfo::new(position, len)),
}
// return chainable self
self
}
/// Apends null to the end of stream, chainable.
///
/// ```rust
/// extern crate ethcore_util as util;
/// use util::rlp::*;
///
/// fn main () {
/// let mut stream = RlpStream::new_list(2);
/// stream.append_empty_data().append_empty_data();
/// let out = stream.out();
/// assert_eq!(out, vec![0xc2, 0x80, 0x80]);
/// }
/// ```
pub fn append_empty_data<'a>(&'a mut self) -> &'a mut RlpStream {
// self push raw item
self.encoder.bytes.push(0x80);
// try to finish and prepend the length
self.note_appended(1);
// return chainable self
self
}
/// Appends raw (pre-serialised) RLP data. Use with caution. Chainable.
pub fn append_raw<'a>(&'a mut self, bytes: &[u8], item_count: usize) -> &'a mut RlpStream {
// push raw items
self.encoder.bytes.extend(bytes);
// try to finish and prepend the length
self.note_appended(item_count);
// return chainable self
self
}
/// Clear the output stream so far.
///
/// ```rust
/// extern crate ethcore_util as util;
/// use util::rlp::*;
///
/// fn main () {
/// let mut stream = RlpStream::new_list(3);
/// stream.append(&"cat");
/// stream.clear();
/// stream.append(&"dog");
/// let out = stream.out();
/// assert_eq!(out, vec![0x83, b'd', b'o', b'g']);
/// }
pub fn clear(&mut self) {
// clear bytes
self.encoder.bytes.clear();
// clear lists
self.unfinished_lists.clear();
}
/// Returns true if stream doesnt expect any more items.
///
/// ```rust
/// extern crate ethcore_util as util;
/// use util::rlp::*;
///
/// fn main () {
/// let mut stream = RlpStream::new_list(2);
/// stream.append(&"cat");
/// assert_eq!(stream.is_finished(), false);
/// stream.append(&"dog");
/// assert_eq!(stream.is_finished(), true);
/// let out = stream.out();
/// assert_eq!(out, vec![0xc8, 0x83, b'c', b'a', b't', 0x83, b'd', b'o', b'g']);
/// }
pub fn is_finished(&self) -> bool {
self.unfinished_lists.back().is_none()
}
/// Streams out encoded bytes.
///
/// panic! if stream is not finished.
pub fn out(self) -> Vec<u8> {
match self.is_finished() {
true => self.encoder.out(),
false => panic!()
}
}
/// Try to finish lists
fn note_appended(&mut self, inserted_items: usize) -> () {
let should_finish = match self.unfinished_lists.back_mut() {
None => false,
Some(ref mut x) => {
x.current += inserted_items;
if x.current > x.max {
panic!("You cannot append more items then you expect!");
}
x.current == x.max
}
};
if should_finish {
let x = self.unfinished_lists.pop_back().unwrap();
let len = self.encoder.bytes.len() - x.position;
self.encoder.insert_list_len_at_pos(len, x.position);
self.note_appended(1);
}
}
}
/// Shortcut function to encode structure into rlp.
///
/// ```rust
/// extern crate ethcore_util as util;
/// use util::rlp::*;
///
/// fn main () {
/// let animals = vec!["cat", "dog"];
/// let out = encode(&animals);
/// assert_eq!(out, vec![0xc8, 0x83, b'c', b'a', b't', 0x83, b'd', b'o', b'g']);
/// }
/// ```
pub fn encode<E>(object: &E) -> Vec<u8> where E: Encodable
{
let mut encoder = BasicEncoder::new();
object.encode(&mut encoder);
encoder.out()
}
pub trait Encodable {
fn encode<E>(&self, encoder: &mut E) -> () where E: Encoder;
}
pub trait Encoder {
fn emit_value(&mut self, bytes: &[u8]) -> ();
fn emit_list<F>(&mut self, f: F) -> () where F: FnOnce(&mut Self) -> ();
}
impl<T> Encodable for T where T: ToBytes {
fn encode<E>(&self, encoder: &mut E) -> () where E: Encoder {
encoder.emit_value(&self.to_bytes())
}
}
impl<'a, T> Encodable for &'a [T] where T: Encodable + 'a {
fn encode<E>(&self, encoder: &mut E) -> () where E: Encoder {
encoder.emit_list(|e| {
// insert all list elements
for el in self.iter() {
el.encode(e);
}
})
}
}
impl<T> Encodable for Vec<T> where T: Encodable {
fn encode<E>(&self, encoder: &mut E) -> () where E: Encoder {
let r: &[T] = self.as_ref();
r.encode(encoder)
}
}
/// lets treat bytes differently than other lists
/// they are a single value
impl<'a> Encodable for &'a [u8] {
fn encode<E>(&self, encoder: &mut E) -> () where E: Encoder {
encoder.emit_value(self)
}
}
/// lets treat bytes differently than other lists
/// they are a single value
impl Encodable for Vec<u8> {
fn encode<E>(&self, encoder: &mut E) -> () where E: Encoder {
encoder.emit_value(self)
}
}
struct BasicEncoder {
bytes: Vec<u8>,
}
impl BasicEncoder {
fn new() -> BasicEncoder {
BasicEncoder { bytes: vec![] }
}
/// inserts list prefix at given position
/// TODO: optimise it further?
fn insert_list_len_at_pos(&mut self, len: usize, pos: usize) -> () {
let mut res = vec![];
match len {
0...55 => res.push(0xc0u8 + len as u8),
_ => {
res.push(0xf7u8 + len.to_bytes_len() as u8);
res.extend(len.to_bytes());
}
};
self.bytes.insert_slice(pos, &res);
}
/// get encoded value
fn out(self) -> Vec<u8> {
self.bytes
}
}
impl Encoder for BasicEncoder {
fn emit_value(&mut self, bytes: &[u8]) -> () {
match bytes.len() {
// just 0
0 => self.bytes.push(0x80u8),
// byte is its own encoding
1 if bytes[0] < 0x80 => self.bytes.extend(bytes),
// (prefix + length), followed by the string
len @ 1 ... 55 => {
self.bytes.push(0x80u8 + len as u8);
self.bytes.extend(bytes);
}
// (prefix + length of length), followed by the length, followd by the string
len => {
self.bytes.push(0xb7 + len.to_bytes_len() as u8);
self.bytes.extend(len.to_bytes());
self.bytes.extend(bytes);
}
}
}
fn emit_list<F>(&mut self, f: F) -> () where F: FnOnce(&mut Self) -> ()
{
// get len before inserting a list
let before_len = self.bytes.len();
// insert all list elements
f(self);
// get len after inserting a list
let after_len = self.bytes.len();
// diff is list len
let list_len = after_len - before_len;
self.insert_list_len_at_pos(list_len, before_len);
}
}
#[cfg(test)]
mod tests {
use std::{fmt, cmp};
use std::str::FromStr;
use rlp;
use rlp::{UntrustedRlp, RlpStream, Decodable};
use uint::U256;
#[test]
fn rlp_at() {
let data = vec![0xc8, 0x83, b'c', b'a', b't', 0x83, b'd', b'o', b'g'];
{
let rlp = UntrustedRlp::new(&data);
assert!(rlp.is_list());
let animals = <Vec<String> as rlp::Decodable>::decode_untrusted(&rlp).unwrap();
assert_eq!(animals, vec!["cat".to_string(), "dog".to_string()]);
let cat = rlp.at(0).unwrap();
assert!(cat.is_data());
assert_eq!(cat.bytes, &[0x83, b'c', b'a', b't']);
assert_eq!(String::decode_untrusted(&cat).unwrap(), "cat".to_string());
let dog = rlp.at(1).unwrap();
assert!(dog.is_data());
assert_eq!(dog.bytes, &[0x83, b'd', b'o', b'g']);
assert_eq!(String::decode_untrusted(&dog).unwrap(), "dog".to_string());
let cat_again = rlp.at(0).unwrap();
assert!(cat_again.is_data());
assert_eq!(cat_again.bytes, &[0x83, b'c', b'a', b't']);
assert_eq!(String::decode_untrusted(&cat_again).unwrap(), "cat".to_string());
}
}
#[test]
fn rlp_at_err() {
let data = vec![0xc8, 0x83, b'c', b'a', b't', 0x83, b'd', b'o'];
{
let rlp = UntrustedRlp::new(&data);
assert!(rlp.is_list());
let cat_err = rlp.at(0).unwrap_err();
assert_eq!(cat_err, rlp::DecoderError::RlpIsTooShort);
let dog_err = rlp.at(1).unwrap_err();
assert_eq!(dog_err, rlp::DecoderError::RlpIsTooShort);
}
}
#[test]
fn rlp_iter() {
let data = vec![0xc8, 0x83, b'c', b'a', b't', 0x83, b'd', b'o', b'g'];
{
let rlp = UntrustedRlp::new(&data);
let mut iter = rlp.iter();
let cat = iter.next().unwrap();
assert!(cat.is_data());
assert_eq!(cat.bytes, &[0x83, b'c', b'a', b't']);
let dog = iter.next().unwrap();
assert!(dog.is_data());
assert_eq!(dog.bytes, &[0x83, b'd', b'o', b'g']);
let none = iter.next();
assert!(none.is_none());
let cat_again = rlp.at(0).unwrap();
assert!(cat_again.is_data());
assert_eq!(cat_again.bytes, &[0x83, b'c', b'a', b't']);
}
}
struct ETestPair<T>(T, Vec<u8>) where T: rlp::Encodable;
fn run_encode_tests<T>(tests: Vec<ETestPair<T>>)
where T: rlp::Encodable
{
for t in &tests {
let res = rlp::encode(&t.0);
assert_eq!(res, &t.1[..]);
}
}
#[test]
fn encode_u16() {
let tests = vec![
ETestPair(0u16, vec![0x80u8]),
ETestPair(0x100, vec![0x82, 0x01, 0x00]),
ETestPair(0xffff, vec![0x82, 0xff, 0xff]),
];
run_encode_tests(tests);
}
#[test]
fn encode_u32() {
let tests = vec![
ETestPair(0u32, vec![0x80u8]),
ETestPair(0x10000, vec![0x83, 0x01, 0x00, 0x00]),
ETestPair(0xffffff, vec![0x83, 0xff, 0xff, 0xff]),
];
run_encode_tests(tests);
}
#[test]
fn encode_u64() {
let tests = vec![
ETestPair(0u64, vec![0x80u8]),
ETestPair(0x1000000, vec![0x84, 0x01, 0x00, 0x00, 0x00]),
ETestPair(0xFFFFFFFF, vec![0x84, 0xff, 0xff, 0xff, 0xff]),
];
run_encode_tests(tests);
}
#[test]
fn encode_u256() {
let tests = vec![ETestPair(U256::from(0u64), vec![0x80u8]),
ETestPair(U256::from(0x1000000u64), vec![0x84, 0x01, 0x00, 0x00, 0x00]),
ETestPair(U256::from(0xffffffffu64),
vec![0x84, 0xff, 0xff, 0xff, 0xff]),
ETestPair(U256::from_str("8090a0b0c0d0e0f00910203040506077000000000000\
000100000000000012f0")
.unwrap(),
vec![0xa0, 0x80, 0x90, 0xa0, 0xb0, 0xc0, 0xd0, 0xe0, 0xf0,
0x09, 0x10, 0x20, 0x30, 0x40, 0x50, 0x60, 0x77, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x12, 0xf0])];
run_encode_tests(tests);
}
#[test]
fn encode_str() {
let tests = vec![ETestPair("cat", vec![0x83, b'c', b'a', b't']),
ETestPair("dog", vec![0x83, b'd', b'o', b'g']),
ETestPair("Marek", vec![0x85, b'M', b'a', b'r', b'e', b'k']),
ETestPair("", vec![0x80]),
ETestPair("Lorem ipsum dolor sit amet, consectetur adipisicing elit",
vec![0xb8, 0x38, b'L', b'o', b'r', b'e', b'm', b' ', b'i',
b'p', b's', b'u', b'm', b' ', b'd', b'o', b'l', b'o',
b'r', b' ', b's', b'i', b't', b' ', b'a', b'm', b'e',
b't', b',', b' ', b'c', b'o', b'n', b's', b'e', b'c',
b't', b'e', b't', b'u', b'r', b' ', b'a', b'd', b'i',
b'p', b'i', b's', b'i', b'c', b'i', b'n', b'g', b' ',
b'e', b'l', b'i', b't'])];
run_encode_tests(tests);
}
#[test]
fn encode_address() {
use hash::*;
let tests = vec![
ETestPair(Address::from_str("ef2d6d194084c2de36e0dabfce45d046b37d1106").unwrap(),
vec![0x94, 0xef, 0x2d, 0x6d, 0x19, 0x40, 0x84, 0xc2, 0xde,
0x36, 0xe0, 0xda, 0xbf, 0xce, 0x45, 0xd0, 0x46,
0xb3, 0x7d, 0x11, 0x06])
];
run_encode_tests(tests);
}
/// Vec<u8> is treated as a single value
#[test]
fn encode_vector_u8() {
let tests = vec![
ETestPair(vec![], vec![0x80]),
ETestPair(vec![0u8], vec![0]),
ETestPair(vec![0x15], vec![0x15]),
ETestPair(vec![0x40, 0x00], vec![0x82, 0x40, 0x00]),
];
run_encode_tests(tests);
}
#[test]
fn encode_vector_u64() {
let tests = vec![
ETestPair(vec![], vec![0xc0]),
ETestPair(vec![15u64], vec![0xc1, 0x0f]),
ETestPair(vec![1, 2, 3, 7, 0xff], vec![0xc6, 1, 2, 3, 7, 0x81, 0xff]),
ETestPair(vec![0xffffffff, 1, 2, 3, 7, 0xff], vec![0xcb, 0x84, 0xff, 0xff, 0xff, 0xff, 1, 2, 3, 7, 0x81, 0xff]),
];
run_encode_tests(tests);
}
#[test]
fn encode_vector_str() {
let tests = vec![ETestPair(vec!["cat", "dog"],
vec![0xc8, 0x83, b'c', b'a', b't', 0x83, b'd', b'o', b'g'])];
run_encode_tests(tests);
}
#[test]
fn encode_vector_of_vectors_str() {
let tests = vec![ETestPair(vec![vec!["cat"]], vec![0xc5, 0xc4, 0x83, b'c', b'a', b't'])];
run_encode_tests(tests);
}
#[test]
fn encode_bytes() {
let vec = vec![0u8];
let slice: &[u8] = &vec;
let res = rlp::encode(&slice);
assert_eq!(res, vec![0u8]);
}
#[test]
fn rlp_stream() {
let mut stream = RlpStream::new_list(2);
stream.append(&"cat").append(&"dog");
let out = stream.out();
assert_eq!(out,
vec![0xc8, 0x83, b'c', b'a', b't', 0x83, b'd', b'o', b'g']);
}
#[test]
fn rlp_stream_list() {
let mut stream = RlpStream::new_list(3);
stream.append_list(0);
stream.append_list(1).append_list(0);
stream.append_list(2).append_list(0).append_list(1).append_list(0);
let out = stream.out();
assert_eq!(out, vec![0xc7, 0xc0, 0xc1, 0xc0, 0xc3, 0xc0, 0xc1, 0xc0]);
}
#[test]
fn rlp_stream_list2() {
let mut stream = RlpStream::new();
stream.append_list(17);
for _ in 0..17 {
stream.append(&"");
}
let out = stream.out();
assert_eq!(out, vec![0xd1, 0x80, 0x80, 0x80, 0x80, 0x80,
0x80, 0x80, 0x80, 0x80, 0x80, 0x80,
0x80, 0x80, 0x80, 0x80, 0x80, 0x80]);
}
#[test]
fn rlp_stream_list3() {
let mut stream = RlpStream::new();
stream.append_list(17);
let mut res = vec![0xf8, 0x44];
for _ in 0..17 {
stream.append(&"aaa");
res.extend(vec![0x83, b'a', b'a', b'a']);
}
let out = stream.out();
assert_eq!(out, res);
}
struct DTestPair<T>(T, Vec<u8>) where T: rlp::Decodable + fmt::Debug + cmp::Eq;
fn run_decode_tests<T>(tests: Vec<DTestPair<T>>) where T: rlp::Decodable + fmt::Debug + cmp::Eq {
for t in &tests {
let res: T = rlp::decode(&t.1);
assert_eq!(res, t.0);
}
}
/// Vec<u8> is treated as a single value
#[test]
fn decode_vector_u8() {
let tests = vec![
DTestPair(vec![], vec![0x80]),
DTestPair(vec![0u8], vec![0]),
DTestPair(vec![0x15], vec![0x15]),
DTestPair(vec![0x40, 0x00], vec![0x82, 0x40, 0x00]),
];
run_decode_tests(tests);
}
#[test]
fn decode_untrusted_u16() {
let tests = vec![
DTestPair(0u16, vec![0u8]),
DTestPair(0x100, vec![0x82, 0x01, 0x00]),
DTestPair(0xffff, vec![0x82, 0xff, 0xff]),
];
run_decode_tests(tests);
}
#[test]
fn decode_untrusted_u32() {
let tests = vec![
DTestPair(0u32, vec![0u8]),
DTestPair(0x10000, vec![0x83, 0x01, 0x00, 0x00]),
DTestPair(0xffffff, vec![0x83, 0xff, 0xff, 0xff]),
];
run_decode_tests(tests);
}
#[test]
fn decode_untrusted_u64() {
let tests = vec![
DTestPair(0u64, vec![0u8]),
DTestPair(0x1000000, vec![0x84, 0x01, 0x00, 0x00, 0x00]),
DTestPair(0xFFFFFFFF, vec![0x84, 0xff, 0xff, 0xff, 0xff]),
];
run_decode_tests(tests);
}
#[test]
fn decode_untrusted_u256() {
let tests = vec![DTestPair(U256::from(0u64), vec![0x80u8]),
DTestPair(U256::from(0x1000000u64), vec![0x84, 0x01, 0x00, 0x00, 0x00]),
DTestPair(U256::from(0xffffffffu64),
vec![0x84, 0xff, 0xff, 0xff, 0xff]),
DTestPair(U256::from_str("8090a0b0c0d0e0f00910203040506077000000000000\
000100000000000012f0")
.unwrap(),
vec![0xa0, 0x80, 0x90, 0xa0, 0xb0, 0xc0, 0xd0, 0xe0, 0xf0,
0x09, 0x10, 0x20, 0x30, 0x40, 0x50, 0x60, 0x77, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x12, 0xf0])];
run_decode_tests(tests);
}
#[test]
fn decode_untrusted_str() {
let tests = vec![DTestPair("cat".to_string(), vec![0x83, b'c', b'a', b't']),
DTestPair("dog".to_string(), vec![0x83, b'd', b'o', b'g']),
DTestPair("Marek".to_string(),
vec![0x85, b'M', b'a', b'r', b'e', b'k']),
DTestPair("".to_string(), vec![0x80]),
DTestPair("Lorem ipsum dolor sit amet, consectetur adipisicing elit"
.to_string(),
vec![0xb8, 0x38, b'L', b'o', b'r', b'e', b'm', b' ', b'i',
b'p', b's', b'u', b'm', b' ', b'd', b'o', b'l', b'o',
b'r', b' ', b's', b'i', b't', b' ', b'a', b'm', b'e',
b't', b',', b' ', b'c', b'o', b'n', b's', b'e', b'c',
b't', b'e', b't', b'u', b'r', b' ', b'a', b'd', b'i',
b'p', b'i', b's', b'i', b'c', b'i', b'n', b'g', b' ',
b'e', b'l', b'i', b't'])];
run_decode_tests(tests);
}
#[test]
fn decode_untrusted_address() {
use hash::*;
let tests = vec![
DTestPair(Address::from_str("ef2d6d194084c2de36e0dabfce45d046b37d1106").unwrap(),
vec![0x94, 0xef, 0x2d, 0x6d, 0x19, 0x40, 0x84, 0xc2, 0xde,
0x36, 0xe0, 0xda, 0xbf, 0xce, 0x45, 0xd0, 0x46,
0xb3, 0x7d, 0x11, 0x06])
];
run_decode_tests(tests);
}
#[test]
fn decode_untrusted_vector_u64() {
let tests = vec![
DTestPair(vec![], vec![0xc0]),
DTestPair(vec![15u64], vec![0xc1, 0x0f]),
DTestPair(vec![1, 2, 3, 7, 0xff], vec![0xc6, 1, 2, 3, 7, 0x81, 0xff]),
DTestPair(vec![0xffffffff, 1, 2, 3, 7, 0xff], vec![0xcb, 0x84, 0xff, 0xff, 0xff, 0xff, 1, 2, 3, 7, 0x81, 0xff]),
];
run_decode_tests(tests);
}
#[test]
fn decode_untrusted_vector_str() {
let tests = vec![DTestPair(vec!["cat".to_string(), "dog".to_string()],
vec![0xc8, 0x83, b'c', b'a', b't', 0x83, b'd', b'o', b'g'])];
run_decode_tests(tests);
}
#[test]
fn decode_untrusted_vector_of_vectors_str() {
let tests = vec![DTestPair(vec![vec!["cat".to_string()]],
vec![0xc5, 0xc4, 0x83, b'c', b'a', b't'])];
run_decode_tests(tests);
}
#[test]
fn test_view() {
struct View<'a> {
bytes: &'a [u8]
}
impl <'a, 'view> View<'a> where 'a: 'view {
fn new(bytes: &'a [u8]) -> View<'a> {
View {
bytes: bytes
}
}
fn offset(&'view self, len: usize) -> View<'a> {
View::new(&self.bytes[len..])
}
fn data(&'view self) -> &'a [u8] {
self.bytes
}
}
let data = vec![0, 1, 2, 3];
let view = View::new(&data);
let _data_slice = view.offset(1).data();
}
}