Merge pull request #252 from ethcore/ark

RLP encoder refactoring

src/block.rs

@@ -45,14 +45,14 @@ impl Decodable for Block {
 		if decoder.as_raw().len() != try!(decoder.as_rlp().payload_info()).total() {
 			return Err(DecoderError::RlpIsTooBig);	
 		}
-		let d = try!(decoder.as_list());
+		let d = decoder.as_rlp();
-		if d.len() != 3 {
+		if d.item_count() != 3 {
 			return Err(DecoderError::RlpIncorrectListLen);
 		}
 		Ok(Block {
-			header: try!(Decodable::decode(&d[0])),
+			header: try!(d.val_at(0)),
-			transactions: try!(Decodable::decode(&d[1])),
+			transactions: try!(d.val_at(1)),
-			uncles: try!(Decodable::decode(&d[2])),
+			uncles: try!(d.val_at(2)),
 		})
 	}
 }
@@ -245,11 +245,11 @@ impl<'x, 'y> OpenBlock<'x, 'y> {
 	pub fn close(self) -> ClosedBlock<'x, 'y> {
 		let mut s = self;
 		s.engine.on_close_block(&mut s.block);
-		s.block.base.header.transactions_root = ordered_trie_root(s.block.base.transactions.iter().map(|ref e| e.rlp_bytes()).collect());
+		s.block.base.header.transactions_root = ordered_trie_root(s.block.base.transactions.iter().map(|ref e| e.rlp_bytes().to_vec()).collect());
 		let uncle_bytes = s.block.base.uncles.iter().fold(RlpStream::new_list(s.block.base.uncles.len()), |mut s, u| {s.append(&u.rlp(Seal::With)); s} ).out();
 		s.block.base.header.uncles_hash = uncle_bytes.sha3();
 		s.block.base.header.state_root = s.block.state.root().clone();
-		s.block.base.header.receipts_root = ordered_trie_root(s.block.receipts.iter().map(|ref r| r.rlp_bytes()).collect());
+		s.block.base.header.receipts_root = ordered_trie_root(s.block.receipts.iter().map(|ref r| r.rlp_bytes().to_vec()).collect());
 		s.block.base.header.log_bloom = s.block.receipts.iter().fold(LogBloom::zero(), |mut b, r| {b |= &r.log_bloom; b});
 		s.block.base.header.gas_used = s.block.receipts.last().map_or(U256::zero(), |r| r.gas_used);
 		s.block.base.header.note_dirty();
@@ -301,8 +301,7 @@ impl SealedBlock {
 	pub fn rlp_bytes(&self) -> Bytes {
 		let mut block_rlp = RlpStream::new_list(3);
 		self.block.base.header.stream_rlp(&mut block_rlp, Seal::With);
-		block_rlp.append_list(self.block.receipts.len());
+		block_rlp.append(&self.block.base.transactions);
-		for t in &self.block.base.transactions { t.rlp_append(&mut block_rlp); }
 		block_rlp.append_raw(&self.uncle_bytes, 1);
 		block_rlp.out()
 	}

src/ethereum/ethash.rs

@@ -48,7 +48,7 @@ impl Engine for Ethash {
 	// Two fields - mix
 	fn seal_fields(&self) -> usize { 2 }
 	// Two empty data items in RLP.
-	fn seal_rlp(&self) -> Bytes { encode(&H64::new()) }
+	fn seal_rlp(&self) -> Bytes { encode(&H64::new()).to_vec() }
 
 	/// Additional engine-specific information for the user/developer concerning `header`.
 	fn extra_info(&self, _header: &Header) -> HashMap<String, String> { HashMap::new() }

src/extras.rs

@@ -133,25 +133,24 @@ impl HeapSizeOf for BlockDetails {
 
 impl Decodable for BlockDetails {
 	fn decode<D>(decoder: &D) -> Result<Self, DecoderError> where D: Decoder {
-		let d = try!(decoder.as_list());
+		let d = decoder.as_rlp();
 		let details = BlockDetails {
-			number: try!(Decodable::decode(&d[0])),
+			number: try!(d.val_at(0)),
-			total_difficulty: try!(Decodable::decode(&d[1])),
+			total_difficulty: try!(d.val_at(1)),
-			parent: try!(Decodable::decode(&d[2])),
+			parent: try!(d.val_at(2)),
-			children: try!(Decodable::decode(&d[3]))
+			children: try!(d.val_at(3)),
 		};
 		Ok(details)
 	}
 }
 
 impl Encodable for BlockDetails {
-	fn encode<E>(&self, encoder: &mut E) where E: Encoder {
+	fn rlp_append(&self, s: &mut RlpStream) {
-		encoder.emit_list(| e | {
+		s.begin_list(4);
-			self.number.encode(e);
+		s.append(&self.number);
-			self.total_difficulty.encode(e);
+		s.append(&self.total_difficulty);
-			self.parent.encode(e);
+		s.append(&self.parent);
-			self.children.encode(e);
+		s.append(&self.children);
-		})
 	}
 }
 
@@ -185,8 +184,8 @@ impl Decodable for BlockLogBlooms {
 }
 
 impl Encodable for BlockLogBlooms {
-	fn encode<E>(&self, encoder: &mut E) where E: Encoder {
+	fn rlp_append(&self, s: &mut RlpStream) {
-		self.blooms.encode(encoder);
+		s.append(&self.blooms);
 	}
 }
 
@@ -231,9 +230,9 @@ impl Decodable for BlocksBlooms {
 }
 
 impl Encodable for BlocksBlooms {
-	fn encode<E>(&self, encoder: &mut E) where E: Encoder {
+	fn rlp_append(&self, s: &mut RlpStream) {
 		let blooms_ref: &[H2048] = &self.blooms;
-		blooms_ref.encode(encoder);
+		s.append(&blooms_ref);
 	}
 }
 
@@ -258,10 +257,10 @@ impl HeapSizeOf for TransactionAddress {
 
 impl Decodable for TransactionAddress {
 	fn decode<D>(decoder: &D) -> Result<Self, DecoderError> where D: Decoder {
-		let d = try!(decoder.as_list());
+		let d = decoder.as_rlp();
 		let tx_address = TransactionAddress {
-			block_hash: try!(Decodable::decode(&d[0])),
+			block_hash: try!(d.val_at(0)),
-			index: try!(Decodable::decode(&d[1]))
+			index: try!(d.val_at(1)),
 		};
 
 		Ok(tx_address)
@@ -269,10 +268,9 @@ impl Decodable for TransactionAddress {
 }
 
 impl Encodable for TransactionAddress {
-	fn encode<E>(&self, encoder: &mut E) where E: Encoder {
+	fn rlp_append(&self, s: &mut RlpStream) {
-		encoder.emit_list(| e | {
+		s.begin_list(2);
-			self.block_hash.encode(e);
+		s.append(&self.block_hash);
-			self.index.encode(e);
+		s.append(&self.index);
-		})
 	}
 }

src/header.rs

@@ -157,7 +157,7 @@ impl Header {
 	// TODO: make these functions traity 
 	/// TODO [Gav Wood] Please document me
 	pub fn stream_rlp(&self, s: &mut RlpStream, with_seal: Seal) {
-		s.append_list(13 + match with_seal { Seal::With => self.seal.len(), _ => 0 });
+		s.begin_list(13 + match with_seal { Seal::With => self.seal.len(), _ => 0 });
 		s.append(&self.parent_hash);
 		s.append(&self.uncles_hash);
 		s.append(&self.author);
@@ -221,26 +221,8 @@ impl Decodable for Header {
 }
 
 impl Encodable for Header {
-	fn encode<E>(&self, encoder: &mut E) where E: Encoder {
+	fn rlp_append(&self, s: &mut RlpStream) {
-		encoder.emit_list(| e | {
+		self.stream_rlp(s, Seal::With);
-			self.parent_hash.encode(e);
-			self.uncles_hash.encode(e);
-			self.author.encode(e);
-			self.state_root.encode(e);
-			self.transactions_root.encode(e);
-			self.receipts_root.encode(e);
-			self.log_bloom.encode(e);
-			self.difficulty.encode(e);
-			self.number.encode(e);
-			self.gas_limit.encode(e);
-			self.gas_used.encode(e);
-			self.timestamp.encode(e);
-			self.extra_data.encode(e);
-
-			for b in &self.seal {
-				e.emit_raw(&b);
-			}
-		})
 	}
 }
 

src/log_entry.rs

@@ -12,9 +12,9 @@ pub struct LogEntry {
 	pub data: Bytes,
 }
 
-impl RlpStandard for LogEntry {
+impl Encodable for LogEntry {
 	fn rlp_append(&self, s: &mut RlpStream) {
-		s.append_list(3);
+		s.begin_list(3);
 		s.append(&self.address);
 		s.append(&self.topics);
 		s.append(&self.data);

src/pod_account.rs

@@ -36,7 +36,7 @@ impl PodAccount {
 		let mut stream = RlpStream::new_list(4);
 		stream.append(&self.nonce);
 		stream.append(&self.balance);
-		stream.append(&sec_trie_root(self.storage.iter().map(|(k, v)| (k.to_vec(), encode(&U256::from(v.as_slice())))).collect()));
+		stream.append(&sec_trie_root(self.storage.iter().map(|(k, v)| (k.to_vec(), encode(&U256::from(v.as_slice())).to_vec())).collect()));
 		stream.append(&self.code.sha3());
 		stream.out()
 	}

src/receipt.rs

@@ -27,17 +27,12 @@ impl Receipt {
 	}
 }
 
-impl RlpStandard for Receipt {
+impl Encodable for Receipt {
 	fn rlp_append(&self, s: &mut RlpStream) {
-		s.append_list(4);
+		s.begin_list(4);
 		s.append(&self.state_root);
 		s.append(&self.gas_used);
 		s.append(&self.log_bloom);
-		// TODO: make work:
+		s.append(&self.logs);
-		//s.append(&self.logs);
-		s.append_list(self.logs.len());
-		for l in &self.logs {
-			l.rlp_append(s);
-		}
 	}
 }

src/spec.rs

@@ -20,14 +20,14 @@ pub fn gzip64res_to_json(source: &[u8]) -> Json {
 // TODO: handle container types.
 fn json_to_rlp(json: &Json) -> Bytes {
 	match *json {
-		Json::Boolean(o) => encode(&(if o {1u64} else {0})),
+		Json::Boolean(o) => encode(&(if o {1u64} else {0})).to_vec(),
-		Json::I64(o) => encode(&(o as u64)),
+		Json::I64(o) => encode(&(o as u64)).to_vec(),
-		Json::U64(o) => encode(&o),
+		Json::U64(o) => encode(&o).to_vec(),
 		Json::String(ref s) if s.len() >= 2 && &s[0..2] == "0x" && U256::from_str(&s[2..]).is_ok() => {
-			encode(&U256::from_str(&s[2..]).unwrap())
+			encode(&U256::from_str(&s[2..]).unwrap()).to_vec()
 		},
 		Json::String(ref s) => {
-			encode(s)
+			encode(s).to_vec()
 		},
 		_ => panic!()
 	}

src/sync/tests.rs

@@ -325,7 +325,6 @@ impl TestNet {
 
 #[test]
 fn chain_two_peers() {
-	::env_logger::init().ok();
 	let mut net = TestNet::new(3);
 	net.peer_mut(1).chain.add_blocks(1000, false);
 	net.peer_mut(2).chain.add_blocks(1000, false);
@@ -336,7 +335,6 @@ fn chain_two_peers() {
 
 #[test]
 fn chain_status_after_sync() {
-	::env_logger::init().ok();
 	let mut net = TestNet::new(3);
 	net.peer_mut(1).chain.add_blocks(1000, false);
 	net.peer_mut(2).chain.add_blocks(1000, false);
@@ -356,7 +354,6 @@ fn chain_takes_few_steps() {
 
 #[test]
 fn chain_empty_blocks() {
-	::env_logger::init().ok();
 	let mut net = TestNet::new(3);
 	for n in 0..200 {
 		net.peer_mut(1).chain.add_blocks(5, n % 2 == 0);
@@ -368,8 +365,7 @@ fn chain_empty_blocks() {
 }
 
 #[test]
-fn chain_forged() {
+fn chain_forked() {
-	::env_logger::init().ok();
 	let mut net = TestNet::new(3);
 	net.peer_mut(0).chain.add_blocks(300, false);
 	net.peer_mut(1).chain.add_blocks(300, false);

src/tests/helpers.rs

@@ -89,14 +89,11 @@ fn create_unverifiable_block(order: u32, parent_hash: H256) -> Bytes {
 pub fn create_test_block_with_data(header: &Header, transactions: &[&Transaction], uncles: &[Header]) -> Bytes {
 	let mut rlp = RlpStream::new_list(3);
 	rlp.append(header);
-	rlp.append_list(transactions.len());
+	rlp.begin_list(transactions.len());
 	for t in transactions {
 		rlp.append_raw(&t.rlp_bytes_opt(Seal::With), 1);
 	}
-	rlp.append_list(uncles.len());
+	rlp.append(&uncles);
-	for h in uncles {
-		rlp.append(h);
-	}
 	rlp.out()
 }
 

src/transaction.rs

@@ -111,7 +111,7 @@ impl Transaction {
 
 	/// Append object into RLP stream, optionally with or without the signature.
 	pub fn rlp_append_opt(&self, s: &mut RlpStream, with_seal: Seal) {
-		s.append_list(6 + match with_seal { Seal::With => 3, _ => 0 });
+		s.begin_list(6 + match with_seal { Seal::With => 3, _ => 0 });
 		s.append(&self.nonce);
 		s.append(&self.gas_price);
 		s.append(&self.gas);
@@ -162,7 +162,7 @@ impl FromJson for Transaction {
 	}
 }
 
-impl RlpStandard for Transaction {
+impl Encodable for Transaction {
 	fn rlp_append(&self, s: &mut RlpStream) { self.rlp_append_opt(s, Seal::With) }
 }
 
@@ -267,20 +267,20 @@ impl Decodable for Action {
 
 impl Decodable for Transaction {
 	fn decode<D>(decoder: &D) -> Result<Self, DecoderError> where D: Decoder {
-		let d = try!(decoder.as_list());
+		let d = decoder.as_rlp();
-		if d.len() != 9 {
+		if d.item_count() != 9 {
 			return Err(DecoderError::RlpIncorrectListLen);
 		}
 		Ok(Transaction {
-			nonce: try!(Decodable::decode(&d[0])),
+			nonce: try!(d.val_at(0)),
-			gas_price: try!(Decodable::decode(&d[1])),
+			gas_price: try!(d.val_at(1)),
-			gas: try!(Decodable::decode(&d[2])),
+			gas: try!(d.val_at(2)),
-			action: try!(Decodable::decode(&d[3])),
+			action: try!(d.val_at(3)),
-			value: try!(Decodable::decode(&d[4])),
+			value: try!(d.val_at(4)),
-			data: try!(Decodable::decode(&d[5])),
+			data: try!(d.val_at(5)),
-			v: try!(u16::decode(&d[6])) as u8,
+			v: try!(d.val_at(6)),
-			r: try!(Decodable::decode(&d[7])),
+			r: try!(d.val_at(7)),
-			s: try!(Decodable::decode(&d[8])),
+			s: try!(d.val_at(8)),
 			hash: RefCell::new(None),
 			sender: RefCell::new(None),
 		})

util/src/bytes.rs

@@ -11,39 +11,55 @@
 //! 	let slice: &[u8] = arr.bytes();
 //! }
 //!
-//! fn to_bytes() {
-//! 	use util::bytes::ToBytes;
-//!
-//! 	let a: Vec<u8> = "hello_world".to_bytes();
-//! 	let b: Vec<u8> = 400u32.to_bytes();
-//! 	let c: Vec<u8> = 0xffffffffffffffffu64.to_bytes();
-//! }
-//!
-//! fn from_bytes() {
-//! 	use util::bytes::FromBytes;
-//!
-//! 	let a = String::from_bytes(&[b'd', b'o', b'g']);
-//! 	let b = u16::from_bytes(&[0xfa]);
-//! 	let c = u64::from_bytes(&[0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff]);
-//! }
-//!
 //! fn main() {
 //! 	bytes_convertable();
-//! 	to_bytes();
-//! 	from_bytes();
 //! }
 //! ```
 
-use std::mem;
 use std::fmt;
 use std::slice;
-use std::cmp::Ordering;
-use std::error::Error as StdError;
 use std::ops::{Deref, DerefMut};
-use uint::{Uint, U128, U256};
 use hash::FixedHash;
+use elastic_array::*;
 
-/// TODO [Gav Wood] Please document me
+/// Vector like object
+pub trait VecLike<T> {
+	/// Add an element to the collection
+    fn vec_push(&mut self, value: T);
+
+	/// Add a slice to the collection
+    fn vec_extend(&mut self, slice: &[T]);
+}
+
+impl<T> VecLike<T> for Vec<T> where T: Copy {
+	fn vec_push(&mut self, value: T) {
+		Vec::<T>::push(self, value)
+	}
+
+	fn vec_extend(&mut self, slice: &[T]) {
+		Vec::<T>::extend_from_slice(self, slice)
+	}
+}
+
+macro_rules! impl_veclike_for_elastic_array {
+	($from: ident) => {
+		impl<T> VecLike<T> for $from<T> where T: Copy {
+			fn vec_push(&mut self, value: T) {
+				$from::<T>::push(self, value)
+			}
+			fn vec_extend(&mut self, slice: &[T]) {
+				$from::<T>::append_slice(self, slice)
+
+			}
+		}
+	}
+}
+
+impl_veclike_for_elastic_array!(ElasticArray16);
+impl_veclike_for_elastic_array!(ElasticArray32);
+impl_veclike_for_elastic_array!(ElasticArray1024);
+
+/// Slie pretty print helper
 pub struct PrettySlice<'a> (&'a [u8]);
 
 impl<'a> fmt::Debug for PrettySlice<'a> {
@@ -166,223 +182,6 @@ fn bytes_convertable() {
 	assert_eq!([0u8; 0].bytes(), &[]);
 }
 
-/// Converts given type to its shortest representation in bytes
-///
-/// TODO: optimise some conversations
-pub trait ToBytes {
-	/// TODO [Gav Wood] Please document me
-	fn to_bytes(&self) -> Vec<u8>;
-	/// TODO [Gav Wood] Please document me
-	fn to_bytes_len(&self) -> usize { self.to_bytes().len() }
-	/// TODO [debris] Please document me
-	fn first_byte(&self) -> Option<u8> { self.to_bytes().first().map(|&x| { x })}
-}
-
-impl <'a> ToBytes for &'a str {
-	fn to_bytes(&self) -> Vec<u8> {
-		From::from(*self)
-	}
-
-	fn to_bytes_len(&self) -> usize { self.len() }
-}
-
-impl ToBytes for String {
-	fn to_bytes(&self) -> Vec<u8> {
-		let s: &str = self.as_ref();
-		From::from(s)
-	}
-
-	fn to_bytes_len(&self) -> usize { self.len() }
-}
-
-impl ToBytes for u64 {
-	fn to_bytes(&self) -> Vec<u8> {
-		let mut res= vec![];
-		let count = self.to_bytes_len();
-		res.reserve(count);
-		for i in 0..count {
-			let j = count - 1 - i;
-			res.push((*self >> (j * 8)) as u8);
-		}
-		res
-	}
-
-	fn to_bytes_len(&self) -> usize { 8 - self.leading_zeros() as usize / 8 }
-}
-
-impl ToBytes for bool {
-	fn to_bytes(&self) -> Vec<u8> {
-		vec![ if *self { 1u8 } else { 0u8 } ]
-	}
-
-	fn to_bytes_len(&self) -> usize { 1 }
-}
-
-macro_rules! impl_map_to_bytes {
-	($from: ident, $to: ty) => {
-		impl ToBytes for $from {
-			fn to_bytes(&self) -> Vec<u8> { (*self as $to).to_bytes() }
-			fn to_bytes_len(&self) -> usize { (*self as $to).to_bytes_len() }
-		}
-	}
-}
-
-impl_map_to_bytes!(usize, u64);
-impl_map_to_bytes!(u16, u64);
-impl_map_to_bytes!(u32, u64);
-
-macro_rules! impl_uint_to_bytes {
-	($name: ident) => {
-		impl ToBytes for $name {
-			fn to_bytes(&self) -> Vec<u8> {
-				let mut res= vec![];
-				let count = self.to_bytes_len();
-				res.reserve(count);
-				for i in 0..count {
-					let j = count - 1 - i;
-					res.push(self.byte(j));
-				}
-				res
-			}
-			fn to_bytes_len(&self) -> usize { (self.bits() + 7) / 8 }
-		}
-	}
-}
-
-impl_uint_to_bytes!(U256);
-impl_uint_to_bytes!(U128);
-
-impl <T>ToBytes for T where T: FixedHash {
-	fn to_bytes(&self) -> Vec<u8> {
-		let mut res: Vec<u8> = vec![];
-		res.reserve(T::size());
-
-		unsafe {
-			use std::ptr;
-			ptr::copy(self.bytes().as_ptr(), res.as_mut_ptr(), T::size());
-			res.set_len(T::size());
-		}
-
-		res
-	}
-}
-
-/// Error returned when FromBytes conversation goes wrong
-#[derive(Debug, PartialEq, Eq)]
-pub enum FromBytesError {
-	/// TODO [debris] Please document me
-	DataIsTooShort,
-	/// TODO [debris] Please document me
-	DataIsTooLong,
-	/// Integer-representation is non-canonically prefixed with zero byte(s).
-	ZeroPrefixedInt,
-}
-
-impl StdError for FromBytesError {
-	fn description(&self) -> &str { "from_bytes error" }
-}
-
-impl fmt::Display for FromBytesError {
-	fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-		fmt::Debug::fmt(&self, f)
-	}
-}
-
-/// Alias for the result of FromBytes trait
-pub type FromBytesResult<T> = Result<T, FromBytesError>;
-
-/// Converts to given type from its bytes representation
-///
-/// TODO: check size of bytes before conversation and return appropriate error
-pub trait FromBytes: Sized {
-	/// TODO [debris] Please document me
-	fn from_bytes(bytes: &[u8]) -> FromBytesResult<Self>;
-}
-
-impl FromBytes for String {
-	fn from_bytes(bytes: &[u8]) -> FromBytesResult<String> {
-		Ok(::std::str::from_utf8(bytes).unwrap().to_owned())
-	}
-}
-
-macro_rules! impl_uint_from_bytes {
-	($to: ident) => {
-		impl FromBytes for $to {
-			fn from_bytes(bytes: &[u8]) -> FromBytesResult<$to> {
-				match bytes.len() {
-					0 => Ok(0),
-					l if l <= mem::size_of::<$to>() => {
-						if bytes[0] == 0 {
-							return Err(FromBytesError::ZeroPrefixedInt)
-						}
-						let mut res = 0 as $to;
-						for i in 0..l {
-							let shift = (l - 1 - i) * 8;
-							res = res + ((bytes[i] as $to) << shift);
-						}
-						Ok(res)
-					}
-					_ => Err(FromBytesError::DataIsTooLong)
-				}
-			}
-		}
-	}
-}
-
-impl FromBytes for bool {
-	fn from_bytes(bytes: &[u8]) -> FromBytesResult<bool> {
-		match bytes.len() {
-			0 => Ok(false),
-			1 => Ok(bytes[0] != 0),
-			_ => Err(FromBytesError::DataIsTooLong),
-		}
-	}
-}
-
-//impl_uint_from_bytes!(u8);
-impl_uint_from_bytes!(u16);
-impl_uint_from_bytes!(u32);
-impl_uint_from_bytes!(u64);
-impl_uint_from_bytes!(usize);
-
-macro_rules! impl_uint_from_bytes {
-	($name: ident) => {
-		impl FromBytes for $name {
-			fn from_bytes(bytes: &[u8]) -> FromBytesResult<$name> {
-				if !bytes.is_empty() && bytes[0] == 0 {
-					Err(FromBytesError::ZeroPrefixedInt)
-				} else if bytes.len() <= $name::SIZE {
-					Ok($name::from(bytes))
-				} else {
-					Err(FromBytesError::DataIsTooLong)
-				}
-			}
-		}
-	}
-}
-
-impl_uint_from_bytes!(U256);
-impl_uint_from_bytes!(U128);
-
-impl <T>FromBytes for T where T: FixedHash {
-	fn from_bytes(bytes: &[u8]) -> FromBytesResult<T> {
-		match bytes.len().cmp(&T::size()) {
-			Ordering::Less => return Err(FromBytesError::DataIsTooShort),
-			Ordering::Greater => return Err(FromBytesError::DataIsTooLong),
-			Ordering::Equal => ()
-		};
-
-		unsafe {
-			use std::{mem, ptr};
-
-			let mut res: T = mem::uninitialized();
-			ptr::copy(bytes.as_ptr(), res.as_slice_mut().as_mut_ptr(), T::size());
-
-			Ok(res)
-		}
-	}
-}
-
 /// Simple trait to allow for raw population of a Sized object from a byte slice.
 pub trait Populatable {
 	/// Copies a bunch of bytes `d` to `self`, overwriting as necessary.

util/src/network/host.rs

@@ -124,11 +124,10 @@ pub struct CapabilityInfo {
 }
 
 impl Encodable for CapabilityInfo {
-	fn encode<E>(&self, encoder: &mut E) -> () where E: Encoder {
+	fn rlp_append(&self, s: &mut RlpStream) {
-		encoder.emit_list(|e| {
+		s.begin_list(2);
-			self.protocol.encode(e);
+		s.append(&self.protocol);
-			(self.version as u32).encode(e);
+		s.append(&self.version);
-		});
 	}
 }
 

util/src/network/session.rs

@@ -57,11 +57,10 @@ pub struct PeerCapabilityInfo {
 
 impl Decodable for PeerCapabilityInfo {
 	fn decode<D>(decoder: &D) -> Result<Self, DecoderError> where D: Decoder {
-		let c = try!(decoder.as_list());
+		let c = decoder.as_rlp();
-		let v: u32 = try!(Decodable::decode(&c[1]));
 		Ok(PeerCapabilityInfo {
-			protocol: try!(Decodable::decode(&c[0])),
+			protocol: try!(c.val_at(0)),
-			version: v as u8,
+			version: try!(c.val_at(1))
 		})
 	}
 }
@@ -199,7 +198,7 @@ impl Session {
 	fn write_hello(&mut self, host: &HostInfo) -> Result<(), UtilError> {
 		let mut rlp = RlpStream::new();
 		rlp.append_raw(&[PACKET_HELLO as u8], 0);
-		rlp.append_list(5)
+		rlp.begin_list(5)
 			.append(&host.protocol_version)
 			.append(&host.client_version)
 			.append(&host.capabilities)
@@ -267,7 +266,7 @@ impl Session {
 	fn disconnect(&mut self, reason: DisconnectReason) -> NetworkError {
 		let mut rlp = RlpStream::new();
 		rlp.append(&(PACKET_DISCONNECT as u32));
-		rlp.append_list(1);
+		rlp.begin_list(1);
 		rlp.append(&(reason.clone() as u32));
 		self.connection.send_packet(&rlp.out()).ok();
 		NetworkError::Disconnect(reason)
@@ -276,7 +275,7 @@ impl Session {
 	fn prepare(packet_id: u8) -> Result<RlpStream, UtilError> {
 		let mut rlp = RlpStream::new();
 		rlp.append(&(packet_id as u32));
-		rlp.append_list(0);
+		rlp.begin_list(0);
 		Ok(rlp)
 	}
 

util/src/overlaydb.rs

@@ -143,7 +143,6 @@ impl OverlayDB {
 			self.backing.delete(&key.bytes()).expect("Low-level database error. Some issue with your hard disk?");
 			true
 		}
-
 	}
 }
 

util/src/rlp/bytes.rs

@@ -0,0 +1,255 @@
+//! Unified interfaces for RLP bytes operations on basic types
+//!
+
+use std::mem;
+use std::fmt;
+use std::cmp::Ordering;
+use std::error::Error as StdError;
+use uint::{Uint, U128, U256};
+use hash::FixedHash;
+use elastic_array::*;
+
+/// Vector like object
+pub trait VecLike<T> {
+	/// Add an element to the collection
+    fn vec_push(&mut self, value: T);
+
+	/// Add a slice to the collection
+    fn vec_extend(&mut self, slice: &[T]);
+}
+
+impl<T> VecLike<T> for Vec<T> where T: Copy {
+	fn vec_push(&mut self, value: T) {
+		Vec::<T>::push(self, value)
+	}
+
+	fn vec_extend(&mut self, slice: &[T]) {
+		Vec::<T>::extend_from_slice(self, slice)
+	}
+}
+
+macro_rules! impl_veclike_for_elastic_array {
+	($from: ident) => {
+		impl<T> VecLike<T> for $from<T> where T: Copy {
+			fn vec_push(&mut self, value: T) {
+				$from::<T>::push(self, value)
+			}
+			fn vec_extend(&mut self, slice: &[T]) {
+				$from::<T>::append_slice(self, slice)
+
+			}
+		}
+	}
+}
+
+impl_veclike_for_elastic_array!(ElasticArray16);
+impl_veclike_for_elastic_array!(ElasticArray32);
+impl_veclike_for_elastic_array!(ElasticArray1024);
+
+/// Converts given type to its shortest representation in bytes
+///
+/// TODO: optimise some conversations
+pub trait ToBytes {
+	/// Serialize self to byte array
+	fn to_bytes<V: VecLike<u8>>(&self, out: &mut V);
+	/// Get length of serialized data in bytes
+	fn to_bytes_len(&self) -> usize;
+}
+
+impl <'a> ToBytes for &'a str {
+	fn to_bytes<V: VecLike<u8>>(&self, out: &mut V) {
+		out.vec_extend(self.as_bytes());
+	}
+
+	fn to_bytes_len(&self) -> usize {
+		self.as_bytes().len()
+	}
+}
+
+impl ToBytes for String {
+	fn to_bytes<V: VecLike<u8>>(&self, out: &mut V) {
+		out.vec_extend(self.as_bytes());
+	}
+
+	fn to_bytes_len(&self) -> usize {
+		self.len()
+	}
+}
+
+impl ToBytes for u64 {
+	fn to_bytes<V: VecLike<u8>>(&self, out: &mut V) {
+		let count = self.to_bytes_len();
+		for i in 0..count {
+			let j = count - 1 - i;
+			out.vec_push((*self >> (j * 8)) as u8);
+		}
+	}
+
+	fn to_bytes_len(&self) -> usize { 8 - self.leading_zeros() as usize / 8 }
+}
+
+impl ToBytes for bool {
+	fn to_bytes<V: VecLike<u8>>(&self, out: &mut V) {
+		out.vec_push(if *self { 1u8 } else { 0u8 })
+	}
+
+	fn to_bytes_len(&self) -> usize { 1 }
+}
+
+macro_rules! impl_map_to_bytes {
+	($from: ident, $to: ty) => {
+		impl ToBytes for $from {
+			fn to_bytes<V: VecLike<u8>>(&self, out: &mut V) {
+				(*self as $to).to_bytes(out)
+			}
+
+			fn to_bytes_len(&self) -> usize { (*self as $to).to_bytes_len() }
+		}
+	}
+}
+
+impl_map_to_bytes!(usize, u64);
+impl_map_to_bytes!(u16, u64);
+impl_map_to_bytes!(u32, u64);
+
+macro_rules! impl_uint_to_bytes {
+	($name: ident) => {
+		impl ToBytes for $name {
+			fn to_bytes<V: VecLike<u8>>(&self, out: &mut V) {
+				let count = self.to_bytes_len();
+				for i in 0..count {
+					let j = count - 1 - i;
+					out.vec_push(self.byte(j));
+				}
+			}
+			fn to_bytes_len(&self) -> usize { (self.bits() + 7) / 8 }
+		}
+	}
+}
+
+impl_uint_to_bytes!(U256);
+impl_uint_to_bytes!(U128);
+
+impl <T>ToBytes for T where T: FixedHash {
+	fn to_bytes<V: VecLike<u8>>(&self, out: &mut V) {
+		out.vec_extend(self.bytes());
+	}
+	fn to_bytes_len(&self) -> usize { self.bytes().len() }
+}
+
+/// Error returned when FromBytes conversation goes wrong
+#[derive(Debug, PartialEq, Eq)]
+pub enum FromBytesError {
+	/// TODO [debris] Please document me
+	DataIsTooShort,
+	/// TODO [debris] Please document me
+	DataIsTooLong,
+	/// Integer-representation is non-canonically prefixed with zero byte(s).
+	ZeroPrefixedInt,
+}
+
+impl StdError for FromBytesError {
+	fn description(&self) -> &str { "from_bytes error" }
+}
+
+impl fmt::Display for FromBytesError {
+	fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+		fmt::Debug::fmt(&self, f)
+	}
+}
+
+/// Alias for the result of FromBytes trait
+pub type FromBytesResult<T> = Result<T, FromBytesError>;
+
+/// Converts to given type from its bytes representation
+///
+/// TODO: check size of bytes before conversation and return appropriate error
+pub trait FromBytes: Sized {
+	/// TODO [debris] Please document me
+	fn from_bytes(bytes: &[u8]) -> FromBytesResult<Self>;
+}
+
+impl FromBytes for String {
+	fn from_bytes(bytes: &[u8]) -> FromBytesResult<String> {
+		Ok(::std::str::from_utf8(bytes).unwrap().to_owned())
+	}
+}
+
+macro_rules! impl_uint_from_bytes {
+	($to: ident) => {
+		impl FromBytes for $to {
+			fn from_bytes(bytes: &[u8]) -> FromBytesResult<$to> {
+				match bytes.len() {
+					0 => Ok(0),
+					l if l <= mem::size_of::<$to>() => {
+						if bytes[0] == 0 {
+							return Err(FromBytesError::ZeroPrefixedInt)
+						}
+						let mut res = 0 as $to;
+						for i in 0..l {
+							let shift = (l - 1 - i) * 8;
+							res = res + ((bytes[i] as $to) << shift);
+						}
+						Ok(res)
+					}
+					_ => Err(FromBytesError::DataIsTooLong)
+				}
+			}
+		}
+	}
+}
+
+impl FromBytes for bool {
+	fn from_bytes(bytes: &[u8]) -> FromBytesResult<bool> {
+		match bytes.len() {
+			0 => Ok(false),
+			1 => Ok(bytes[0] != 0),
+			_ => Err(FromBytesError::DataIsTooLong),
+		}
+	}
+}
+
+//impl_uint_from_bytes!(u8);
+impl_uint_from_bytes!(u16);
+impl_uint_from_bytes!(u32);
+impl_uint_from_bytes!(u64);
+impl_uint_from_bytes!(usize);
+
+macro_rules! impl_uint_from_bytes {
+	($name: ident) => {
+		impl FromBytes for $name {
+			fn from_bytes(bytes: &[u8]) -> FromBytesResult<$name> {
+				if !bytes.is_empty() && bytes[0] == 0 {
+					Err(FromBytesError::ZeroPrefixedInt)
+				} else if bytes.len() <= $name::SIZE {
+					Ok($name::from(bytes))
+				} else {
+					Err(FromBytesError::DataIsTooLong)
+				}
+			}
+		}
+	}
+}
+
+impl_uint_from_bytes!(U256);
+impl_uint_from_bytes!(U128);
+
+impl <T>FromBytes for T where T: FixedHash {
+	fn from_bytes(bytes: &[u8]) -> FromBytesResult<T> {
+		match bytes.len().cmp(&T::size()) {
+			Ordering::Less => return Err(FromBytesError::DataIsTooShort),
+			Ordering::Greater => return Err(FromBytesError::DataIsTooLong),
+			Ordering::Equal => ()
+		};
+
+		unsafe {
+			use std::{mem, ptr};
+
+			let mut res: T = mem::uninitialized();
+			ptr::copy(bytes.as_ptr(), res.as_slice_mut().as_mut_ptr(), T::size());
+
+			Ok(res)
+		}
+	}
+}
+

util/src/rlp/mod.rs

@@ -30,25 +30,22 @@
 //! * You want to get view onto rlp-slice.
 //! * You don't want to decode whole rlp at once.
 
-/// TODO [Gav Wood] Please document me
 pub mod rlptraits;
-/// TODO [Gav Wood] Please document me
+mod rlperrors;
-pub mod rlperrors;
+mod rlpin;
-/// TODO [debris] Please document me
+mod untrusted_rlp;
-pub mod rlpin;
+mod rlpstream;
-/// TODO [debris] Please document me
+mod bytes;
-pub mod untrusted_rlp;
-/// TODO [debris] Please document me
-pub mod rlpstream;
 
 #[cfg(test)]
 mod tests;
 
 pub use self::rlperrors::DecoderError;
-pub use self::rlptraits::{Decoder, Decodable, View, Stream, Encodable, Encoder};
+pub use self::rlptraits::{Decoder, Decodable, View, Stream, Encodable, Encoder, RlpEncodable, RlpDecodable};
 pub use self::untrusted_rlp::{UntrustedRlp, UntrustedRlpIterator, PayloadInfo, Prototype};
 pub use self::rlpin::{Rlp, RlpIterator};
-pub use self::rlpstream::{RlpStream,RlpStandard};
+pub use self::rlpstream::{RlpStream};
+pub use elastic_array::ElasticArray1024;
 use super::hash::H256;
 
 /// TODO [arkpar] Please document me
@@ -72,7 +69,7 @@ pub const SHA3_EMPTY_LIST_RLP: H256 = H256( [0x1d, 0xcc, 0x4d, 0xe8, 0xde, 0xc7,
 /// 	assert_eq!(animals, vec!["cat".to_string(), "dog".to_string()]);
 /// }
 /// ```
-pub fn decode<T>(bytes: &[u8]) -> T where T: Decodable {
+pub fn decode<T>(bytes: &[u8]) -> T where T: RlpDecodable {
 	let rlp = Rlp::new(bytes);
 	rlp.as_val()
 }
@@ -84,13 +81,13 @@ pub fn decode<T>(bytes: &[u8]) -> T where T: Decodable {
 /// use util::rlp::*;
 ///
 /// fn main () {
-/// 	let animals = vec!["cat", "dog"];
+/// 	let animal = "cat";
-/// 	let out = encode(&animals);
+/// 	let out = encode(&animal).to_vec();
-/// 	assert_eq!(out, vec![0xc8, 0x83, b'c', b'a', b't', 0x83, b'd', b'o', b'g']);
+/// 	assert_eq!(out, vec![0x83, b'c', b'a', b't']);
 /// }
 /// ```
-pub fn encode<E>(object: &E) -> Vec<u8> where E: Encodable {
+pub fn encode<E>(object: &E) -> ElasticArray1024<u8> where E: RlpEncodable {
 	let mut stream = RlpStream::new();
 	stream.append(object);
-	stream.out()
+	stream.drain()
 }

util/src/rlp/rlperrors.rs

@@ -1,6 +1,6 @@
 use std::fmt;
 use std::error::Error as StdError;
-use bytes::FromBytesError;
+use rlp::bytes::FromBytesError;
 
 #[derive(Debug, PartialEq, Eq)]
 /// TODO [debris] Please document me

util/src/rlp/rlpin.rs

@@ -1,5 +1,5 @@
 use std::fmt;
-use rlp::{View, Decodable, DecoderError, UntrustedRlp, PayloadInfo, Prototype};
+use rlp::{View, DecoderError, UntrustedRlp, PayloadInfo, Prototype, RlpDecodable};
 
 impl<'a> From<UntrustedRlp<'a>> for Rlp<'a> {
 	fn from(rlp: UntrustedRlp<'a>) -> Rlp<'a> {
@@ -88,28 +88,28 @@ impl<'a, 'view> View<'a, 'view> for Rlp<'a> where 'a: 'view {
 		self.into_iter()
 	}
 
-	fn as_val<T>(&self) -> Result<T, DecoderError> where T: Decodable {
+	fn as_val<T>(&self) -> Result<T, DecoderError> where T: RlpDecodable {
 		self.rlp.as_val()
 	}
 
-	fn val_at<T>(&self, index: usize) -> Result<T, DecoderError> where T: Decodable {
+	fn val_at<T>(&self, index: usize) -> Result<T, DecoderError> where T: RlpDecodable {
 		self.at(index).rlp.as_val()
 	}
 }
 
 impl <'a, 'view> Rlp<'a> where 'a: 'view {
-	fn view_as_val<T, R>(r: &R) -> T where R: View<'a, 'view>, T: Decodable {
+	fn view_as_val<T, R>(r: &R) -> T where R: View<'a, 'view>, T: RlpDecodable {
 		let res: Result<T, DecoderError> = r.as_val();
 		res.unwrap_or_else(|_| panic!())
 	}
 
 	/// TODO [debris] Please document me
-	pub fn as_val<T>(&self) -> T where T: Decodable {
+	pub fn as_val<T>(&self) -> T where T: RlpDecodable {
 		Self::view_as_val(self)
 	}
 
 	/// TODO [debris] Please document me
-	pub fn val_at<T>(&self, index: usize) -> T where T: Decodable {
+	pub fn val_at<T>(&self, index: usize) -> T where T: RlpDecodable {
 		Self::view_as_val(&self.at(index))
 	}
 }

util/src/rlp/rlpstream.rs

@@ -1,8 +1,8 @@
+use std::ops::Deref;
 use elastic_array::*;
-use bytes::{Bytes, ToBytes};
+use rlp::bytes::{ToBytes, VecLike};
 use rlp::{Stream, Encoder, Encodable};
-use hash::H256;
+use rlp::rlptraits::{ByteEncodable, RlpEncodable};
-use sha3::*;
 
 #[derive(Debug, Copy, Clone)]
 struct ListInfo {
@@ -25,6 +25,7 @@ impl ListInfo {
 pub struct RlpStream {
 	unfinished_lists: ElasticArray16<ListInfo>,
 	encoder: BasicEncoder,
+	finished_list: bool,
 }
 
 impl Stream for RlpStream {
@@ -32,27 +33,27 @@ impl Stream for RlpStream {
 		RlpStream {
 			unfinished_lists: ElasticArray16::new(),
 			encoder: BasicEncoder::new(),
+			finished_list: false,
 		}
 	}
 
 	fn new_list(len: usize) -> Self {
 		let mut stream = RlpStream::new();
-		stream.append_list(len);
+		stream.begin_list(len);
 		stream
 	}
 
-	fn append<E>(&mut self, object: &E) -> &mut RlpStream where E: Encodable {
+	fn append<'a, E>(&'a mut self, value: &E) -> &'a mut Self where E: RlpEncodable {
-		// encode given value and add it at the end of the stream
+		self.finished_list = false;
-		object.encode(&mut self.encoder);
+		value.rlp_append(self);
-
+		if !self.finished_list {
-		// if list is finished, prepend the length
 			self.note_appended(1);
-
+		}
-		// return chainable self
 		self
 	}
 
-	fn append_list(&mut self, len: usize) -> &mut RlpStream {
+	fn begin_list(&mut self, len: usize) -> &mut RlpStream {
+		self.finished_list = false;
 		match len {
 			0 => {
 				// we may finish, if the appended list len is equal 0
@@ -117,6 +118,21 @@ impl Stream for RlpStream {
 
 impl RlpStream {
 
+	/// Appends primitive value to the end of stream
+	fn append_value<E>(&mut self, object: &E) where E: ByteEncodable {
+		// encode given value and add it at the end of the stream
+		self.encoder.emit_value(object);
+	}
+
+	fn append_internal<'a, E>(&'a mut self, value: &E) -> &'a mut Self where E: Encodable {
+		self.finished_list = false;
+		value.rlp_append(self);
+		if !self.finished_list {
+			self.note_appended(1);
+		}
+		self
+	}
+
 	/// Try to finish lists
 	fn note_appended(&mut self, inserted_items: usize) -> () {
 		if self.unfinished_lists.len() == 0 {
@@ -141,6 +157,7 @@ impl RlpStream {
 			self.encoder.insert_list_len_at_pos(len, x.position);
 			self.note_appended(1);
 		}
+		self.finished_list = should_finish;
 	}
 
 	/// Drain the object and return the underlying ElasticArray.
@@ -164,12 +181,12 @@ impl BasicEncoder {
 	/// 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![];
+		let mut res = ElasticArray16::new();
 		match len {
 			0...55 => res.push(0xc0u8 + len as u8),
 			_ => {
 				res.push(0xf7u8 + len.to_bytes_len() as u8);
-				res.extend(len.to_bytes());
+				ToBytes::to_bytes(&len, &mut res);
 			}
 		};
 
@@ -183,22 +200,30 @@ impl BasicEncoder {
 }
 
 impl Encoder for BasicEncoder {
-	fn emit_value(&mut self, bytes: &[u8]) -> () {
+	fn emit_value<E: ByteEncodable>(&mut self, value: &E) {
-		match bytes.len() {
+		match value.bytes_len() {
 			// just 0
 			0 => self.bytes.push(0x80u8),
-			// byte is its own encoding
+			// byte is its own encoding if < 0x80
-			1 if bytes[0] < 0x80 => self.bytes.append_slice(bytes),
+			1 => { 
+				value.to_bytes(&mut self.bytes);
+				let len = self.bytes.len();
+				let last_byte = self.bytes[len - 1];
+				if last_byte >= 0x80 {
+					self.bytes.push(last_byte);
+					self.bytes[len - 1] = 0x81;
+				}
+			}
 			// (prefix + length), followed by the string
-			len @ 1 ... 55 => {
+			len @ 2 ... 55 => {
 				self.bytes.push(0x80u8 + len as u8);
-				self.bytes.append_slice(bytes);
+				value.to_bytes(&mut self.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.append_slice(&len.to_bytes());
+				ToBytes::to_bytes(&len, &mut self.bytes);
-				self.bytes.append_slice(bytes);
+				value.to_bytes(&mut self.bytes);
 			}
 		}
 	}
@@ -206,86 +231,82 @@ impl Encoder for BasicEncoder {
 	fn emit_raw(&mut self, bytes: &[u8]) -> () {
 		self.bytes.append_slice(bytes);
 	}
+}
 
-	fn emit_list<F>(&mut self, f: F) -> () where F: FnOnce(&mut Self) -> () {
+impl<T> ByteEncodable for T where T: ToBytes {
-		// get len before inserting a list
+	fn to_bytes<V: VecLike<u8>>(&self, out: &mut V) {
-		let before_len = self.bytes.len();
+		ToBytes::to_bytes(self, out)
+	}
 
-		// insert all list elements
+	fn bytes_len(&self) -> usize {
-		f(self);
+		ToBytes::to_bytes_len(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);
 	}
 }
 
-/// TODO [Gav Wood] Please document me
+struct U8Slice<'a>(&'a [u8]);
-pub trait RlpStandard {
-	/// TODO [Gav Wood] Please document me
-	fn rlp_append(&self, s: &mut RlpStream);
 
-	/// TODO [Gav Wood] Please document me
+impl<'a> ByteEncodable for U8Slice<'a> {
-	fn rlp_bytes(&self) -> Bytes {
+	fn to_bytes<V: VecLike<u8>>(&self, out: &mut V) {
-		let mut s = RlpStream::new();
+		out.vec_extend(self.0)
-		self.rlp_append(&mut s);
-		s.out()
 	}
 
-	/// TODO [Gav Wood] Please document me
+	fn bytes_len(&self) -> usize {
-	fn rlp_sha3(&self) -> H256 { self.rlp_bytes().sha3() }
+		self.0.len()
-}
-
-// @debris TODO: implement Encoder for RlpStandard.
-
-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 {
+impl<'a> Encodable for &'a[u8] {
-	fn encode<E>(&self, encoder: &mut E) where E: Encoder {
+	fn rlp_append(&self, s: &mut RlpStream) {
-		encoder.emit_list(|e| {
+		s.append_value(&U8Slice(self))
-			// insert all list elements
+	}
+}
+
+impl Encodable for Vec<u8> {
+	fn rlp_append(&self, s: &mut RlpStream) {
+		s.append_value(&U8Slice(self.deref()))
+	}
+}
+
+impl<T> Encodable for T where T: ByteEncodable {
+	fn rlp_append(&self, s: &mut RlpStream) {
+		s.append_value(self)
+	}
+}
+
+struct EncodableU8 (u8);
+
+impl ByteEncodable for EncodableU8 {
+	fn to_bytes<V: VecLike<u8>>(&self, out: &mut V) {
+		out.vec_push(self.0)
+	}
+
+	fn bytes_len(&self) -> usize { 1 }
+}
+
+impl RlpEncodable for u8 {
+	fn rlp_append(&self, s: &mut RlpStream) {
+		s.append_value(&EncodableU8(*self))
+	}
+}
+
+impl<'a, T> Encodable for &'a[T] where T: Encodable {
+	fn rlp_append(&self, s: &mut RlpStream) {
+		s.begin_list(self.len());
 		for el in self.iter() {
-				el.encode(e);
+			s.append_internal(el);
 		}
-		})
 	}
 }
 
 impl<T> Encodable for Vec<T>  where T: Encodable {
-	fn encode<E>(&self, encoder: &mut E) where E: Encoder {
+	fn rlp_append(&self, s: &mut RlpStream) {
-		let r: &[T] = self.as_ref();
+		Encodable::rlp_append(&self.deref(), s);
-		r.encode(encoder)
 	}
 }
 
-/// lets treat bytes differently than other lists
+impl<T> RlpEncodable for T where T: Encodable {
-/// they are a single value
+	fn rlp_append(&self, s: &mut RlpStream) {
-impl<'a> Encodable for &'a [u8] {
+		Encodable::rlp_append(self, s)
-	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)
-	}
-}
-
-impl<T> Encodable for Option<T> where T: Encodable {
-	fn encode<E>(&self, encoder: &mut E) where E: Encoder {
-		match *self {
-			Some(ref x) => x.encode(encoder),
-			None => encoder.emit_value(&[])
-		}
-	}
-}

util/src/rlp/rlptraits.rs

@@ -1,4 +1,11 @@
+//! Common RLP traits
+use std::ops::Deref;
+use rlp::bytes::VecLike;
 use rlp::{DecoderError, UntrustedRlp};
+use rlp::rlpstream::RlpStream;
+use elastic_array::ElasticArray1024;
+use hash::H256;
+use sha3::*;
 
 /// TODO [debris] Please document me
 pub trait Decoder: Sized {
@@ -6,17 +13,21 @@ pub trait Decoder: Sized {
 	fn read_value<T, F>(&self, f: F) -> Result<T, DecoderError>
 		where F: FnOnce(&[u8]) -> Result<T, DecoderError>;
 
-	/// TODO [arkpar] Please document me
-	fn as_list(&self) -> Result<Vec<Self>, DecoderError>;
 	/// TODO [Gav Wood] Please document me
 	fn as_rlp(&self) -> &UntrustedRlp;
 	/// TODO [debris] Please document me
 	fn as_raw(&self) -> &[u8];
 }
 
-/// TODO [debris] Please document me
+/// RLP decodable trait
 pub trait Decodable: Sized {
-	/// TODO [debris] Please document me
+	/// Decode a value from RLP bytes
+	fn decode<D>(decoder: &D) -> Result<Self, DecoderError>  where D: Decoder;
+}
+
+/// Internal helper trait. Implement `Decodable` for custom types.
+pub trait RlpDecodable: Sized {
+	/// Decode a value from RLP bytes
 	fn decode<D>(decoder: &D) -> Result<Self, DecoderError>  where D: Decoder;
 }
 
@@ -195,26 +206,48 @@ pub trait View<'a, 'view>: Sized {
 	fn iter(&'view self) -> Self::Iter;
 
 	/// TODO [debris] Please document me
-	fn as_val<T>(&self) -> Result<T, DecoderError> where T: Decodable;
+	fn as_val<T>(&self) -> Result<T, DecoderError> where T: RlpDecodable;
 
 	/// TODO [debris] Please document me
-	fn val_at<T>(&self, index: usize) -> Result<T, DecoderError> where T: Decodable;
+	fn val_at<T>(&self, index: usize) -> Result<T, DecoderError> where T: RlpDecodable;
 }
 
 /// TODO [debris] Please document me
 pub trait Encoder {
 	/// TODO [debris] Please document me
-	fn emit_value(&mut self, bytes: &[u8]) -> ();
+	fn emit_value<E: ByteEncodable>(&mut self, value: &E);
-	/// TODO [Gav Wood] Please document me
-	fn emit_list<F>(&mut self, f: F) -> () where F: FnOnce(&mut Self) -> ();
 	/// TODO [debris] Please document me
 	fn emit_raw(&mut self, bytes: &[u8]) -> ();
 }
 
-/// TODO [debris] Please document me
+/// Primitive data type encodable to RLP
+pub trait ByteEncodable {
+	/// Serialize this object to given byte container
+	fn to_bytes<V: VecLike<u8>>(&self, out: &mut V);
+	/// Get size of serialised data in bytes
+	fn bytes_len(&self) -> usize;
+}
+
+/// Structure encodable to RLP. Implement this trait for 
 pub trait Encodable {
-	/// TODO [debris] Please document me
+	/// Append a value to the stream
-	fn encode<E>(&self, encoder: &mut E) -> () where E: Encoder;
+	fn rlp_append(&self, s: &mut RlpStream);
+
+	/// Get rlp-encoded bytes for this instance
+	fn rlp_bytes(&self) -> ElasticArray1024<u8> {
+		let mut s = RlpStream::new();
+		self.rlp_append(&mut s);
+		s.drain()
+	}
+
+	/// Get the hash or RLP encoded representation
+	fn rlp_sha3(&self) -> H256 { self.rlp_bytes().deref().sha3() }
+}
+
+/// Encodable wrapper trait required to handle special case of encoding a &[u8] as string and not as list
+pub trait RlpEncodable {
+	/// Append a value to the stream
+	fn rlp_append(&self, s: &mut RlpStream);
 }
 
 /// TODO [debris] Please document me
@@ -239,7 +272,7 @@ pub trait Stream: Sized {
 	/// 	assert_eq!(out, vec![0xc8, 0x83, b'c', b'a', b't', 0x83, b'd', b'o', b'g']);
 	/// }
 	/// ```
-	fn append<'a, E>(&'a mut self, object: &E) -> &'a mut Self where E: Encodable;
+	fn append<'a, E>(&'a mut self, value: &E) -> &'a mut Self where E: RlpEncodable;
 
 	/// Declare appending the list of given size, chainable.
 	///
@@ -249,13 +282,13 @@ pub trait Stream: Sized {
 	///
 	/// fn main () {
 	/// 	let mut stream = RlpStream::new_list(2);
-	/// 	stream.append_list(2).append(&"cat").append(&"dog");
+	/// 	stream.begin_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]);
 	/// }
 	/// ```
-	fn append_list(&mut self, len: usize) -> &mut Self;
+	fn begin_list(&mut self, len: usize) -> &mut Self;
 
 	/// Apends null to the end of stream, chainable.
 	///

util/src/rlp/tests.rs

@@ -13,7 +13,7 @@ fn rlp_at() {
 	{
 		let rlp = UntrustedRlp::new(&data);
 		assert!(rlp.is_list());
-		//let animals = <Vec<String> as rlp::Decodable>::decode_untrusted(&rlp).unwrap();
+		//let animals = <Vec<String> as rlp::RlpDecodable>::decode_untrusted(&rlp).unwrap();
 		let animals: Vec<String> = rlp.as_val().unwrap();
 		assert_eq!(animals, vec!["cat".to_owned(), "dog".to_owned()]);
 
@@ -83,7 +83,7 @@ fn run_encode_tests<T>(tests: Vec<ETestPair<T>>)
 {
 	for t in &tests {
 		let res = rlp::encode(&t.0);
-		assert_eq!(res, &t.1[..]);
+		assert_eq!(&res[..], &t.1[..]);
 	}
 }
 
@@ -193,15 +193,9 @@ fn encode_vector_str() {
 	run_encode_tests(tests);
 }
 
-#[test]
+struct DTestPair<T>(T, Vec<u8>) where T: rlp::RlpDecodable + fmt::Debug + cmp::Eq;
-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);
-}
 
-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::RlpDecodable + 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);
@@ -220,12 +214,21 @@ fn decode_vector_u8() {
 	run_decode_tests(tests);
 }
 
+#[test]
+fn decode_untrusted_u8() {
+	let tests = vec![
+		DTestPair(0x0u8, vec![0x80]),
+		DTestPair(0x77u8, vec![0x77]),
+		DTestPair(0xccu8, vec![0x81, 0xcc]),
+	];
+	run_decode_tests(tests);
+}
+
 #[test]
 fn decode_untrusted_u16() {
 	let tests = vec![
-		DTestPair(0u16, vec![0u8]),
+		DTestPair(0x100u16, vec![0x82, 0x01, 0x00]),
-		DTestPair(0x100, vec![0x82, 0x01, 0x00]),
+		DTestPair(0xffffu16, vec![0x82, 0xff, 0xff]),
-		DTestPair(0xffff, vec![0x82, 0xff, 0xff]),
 	];
 	run_decode_tests(tests);
 }
@@ -233,9 +236,8 @@ fn decode_untrusted_u16() {
 #[test]
 fn decode_untrusted_u32() {
 	let tests = vec![
-		DTestPair(0u32, vec![0u8]),
+		DTestPair(0x10000u32, vec![0x83, 0x01, 0x00, 0x00]),
-		DTestPair(0x10000, vec![0x83, 0x01, 0x00, 0x00]),
+		DTestPair(0xffffffu32, vec![0x83, 0xff, 0xff, 0xff]),
-		DTestPair(0xffffff, vec![0x83, 0xff, 0xff, 0xff]),
 	];
 	run_decode_tests(tests);
 }
@@ -243,9 +245,8 @@ fn decode_untrusted_u32() {
 #[test]
 fn decode_untrusted_u64() {
 	let tests = vec![
-		DTestPair(0u64, vec![0u8]),
+		DTestPair(0x1000000u64, vec![0x84, 0x01, 0x00, 0x00, 0x00]),
-		DTestPair(0x1000000, vec![0x84, 0x01, 0x00, 0x00, 0x00]),
+		DTestPair(0xFFFFFFFFu64, vec![0x84, 0xff, 0xff, 0xff, 0xff]),
-		DTestPair(0xFFFFFFFF, vec![0x84, 0xff, 0xff, 0xff, 0xff]),
 	];
 	run_decode_tests(tests);
 }
@@ -333,7 +334,7 @@ fn test_rlp_json() {
 		for operation in input.into_iter() {
 			match operation {
 				rlptest::Operation::Append(ref v) => stream.append(v),
-				rlptest::Operation::AppendList(len) => stream.append_list(len),
+				rlptest::Operation::AppendList(len) => stream.begin_list(len),
 				rlptest::Operation::AppendRaw(ref raw, len) => stream.append_raw(raw, len),
 				rlptest::Operation::AppendEmpty => stream.append_empty_data()
 			};

util/src/rlp/untrusted_rlp.rs

@@ -1,8 +1,8 @@
 use std::cell::Cell;
 use std::fmt;
 use rustc_serialize::hex::ToHex;
-use bytes::{FromBytes};
+use rlp::bytes::{FromBytes, FromBytesResult, FromBytesError};
-use rlp::{View, Decoder, Decodable, DecoderError};
+use rlp::{View, Decoder, Decodable, DecoderError, RlpDecodable};
 
 /// rlp offset
 #[derive(Copy, Clone, Debug)]
@@ -211,12 +211,12 @@ impl<'a, 'view> View<'a, 'view> for UntrustedRlp<'a> where 'a: 'view {
 		self.into_iter()
 	}
 
-	fn as_val<T>(&self) -> Result<T, DecoderError> where T: Decodable {
+	fn as_val<T>(&self) -> Result<T, DecoderError> where T: RlpDecodable {
 		// optimize, so it doesn't use clone (although This clone is cheap)
 		T::decode(&BasicDecoder::new(self.clone()))
 	}
 
-	fn val_at<T>(&self, index: usize) -> Result<T, DecoderError> where T: Decodable {
+	fn val_at<T>(&self, index: usize) -> Result<T, DecoderError> where T: RlpDecodable {
 		try!(self.at(index)).as_val()
 	}
 }
@@ -369,13 +369,6 @@ impl<'a> Decoder for BasicDecoder<'a> {
 		self.rlp.as_raw()
 	}
 
-	fn as_list(&self) -> Result<Vec<Self>, DecoderError> {
-		let v: Vec<BasicDecoder<'a>> = self.rlp.iter()
-			.map(BasicDecoder::new)
-			.collect();
-		Ok(v)
-	}
-
 	fn as_rlp(&self) -> &UntrustedRlp {
 		&self.rlp
 	}
@@ -391,8 +384,7 @@ impl<T> Decodable for T where T: FromBytes {
 
 impl<T> Decodable for Vec<T> where T: Decodable {
 	fn decode<D>(decoder: &D) -> Result<Self, DecoderError>  where D: Decoder {
-		let decoders = try!(decoder.as_list());
+		decoder.as_rlp().iter().map(|d| T::decode(&BasicDecoder::new(d))).collect()
-		decoders.iter().map(|d| T::decode(d)).collect()
 	}
 }
 
@@ -423,15 +415,15 @@ macro_rules! impl_array_decodable {
 		impl<T> Decodable for [T; $len] where T: Decodable {
 			#[allow(len_zero)]
 			fn decode<D>(decoder: &D) -> Result<Self, DecoderError>  where D: Decoder {
-				let decoders = try!(decoder.as_list());
+				let decoders = decoder.as_rlp();
 
 				let mut result: [T; $len] = unsafe { ::std::mem::uninitialized() };
-				if decoders.len() != $len {
+				if decoders.item_count() != $len {
 					return Err(DecoderError::RlpIncorrectListLen);
 				}
 
-				for i in 0..decoders.len() {
+				for i in 0..decoders.item_count() {
-					result[i] = try!(T::decode(&decoders[i]));
+					result[i] = try!(T::decode(&BasicDecoder::new(try!(decoders.at(i)))));
 				}
 
 				Ok(result)
@@ -454,6 +446,36 @@ impl_array_decodable_recursive!(
 	32, 40, 48, 56, 64, 72, 96, 128, 160, 192, 224,
 );
 
+impl<T> RlpDecodable for T where T: Decodable {
+	fn decode<D>(decoder: &D) -> Result<Self, DecoderError>  where D: Decoder {
+		Decodable::decode(decoder)
+	}
+}
+
+struct DecodableU8 (u8);
+
+impl FromBytes for DecodableU8 {
+	fn from_bytes(bytes: &[u8]) -> FromBytesResult<DecodableU8> {
+		match bytes.len() {
+			0 => Ok(DecodableU8(0u8)),
+			1 => {
+				if bytes[0] == 0 {
+					return Err(FromBytesError::ZeroPrefixedInt)
+				}
+				Ok(DecodableU8(bytes[0]))
+			}
+			_ => Err(FromBytesError::DataIsTooLong)
+		}
+	}
+}
+
+impl RlpDecodable for u8 {
+	fn decode<D>(decoder: &D) -> Result<Self, DecoderError>  where D: Decoder {
+		let u: DecodableU8 = try!(Decodable::decode(decoder));
+		Ok(u.0)
+	}
+}
+
 #[test]
 fn test_rlp_display() {
 	use rustc_serialize::hex::FromHex;

util/src/trie/node.rs

@@ -89,17 +89,17 @@ impl<'a> Node<'a> {
 		let mut stream = RlpStream::new();
 		match *self {
 			Node::Leaf(ref slice, ref value) => {
-				stream.append_list(2);
+				stream.begin_list(2);
 				stream.append(&slice.encoded(true));
 				stream.append(value);
 			},
 			Node::Extension(ref slice, ref raw_rlp) => {
-				stream.append_list(2);
+				stream.begin_list(2);
 				stream.append(&slice.encoded(false));
 				stream.append_raw(raw_rlp, 1);
 			},
 			Node::Branch(ref nodes, ref value) => {
-				stream.append_list(17);
+				stream.begin_list(17);
 				for i in 0..16 {
 					stream.append_raw(nodes[i], 1);
 				}

util/src/trie/triedbmut.rs

@@ -671,7 +671,6 @@ mod tests {
 	use super::*;
 	use nibbleslice::*;
 	use rlp::*;
-	use env_logger;
 	use rand::random;
 	use std::collections::HashSet;
 	use bytes::{ToPretty,Bytes,Populatable};
@@ -689,11 +688,11 @@ mod tests {
 	
 	fn random_value_indexed(j: usize) -> Bytes {
 		match random::<usize>() % 2 {
-			0 => encode(&j),
+			0 => encode(&j).to_vec(),
 			_ => {
 				let mut h = H256::new();
 				h.as_slice_mut()[31] = j as u8;
-				encode(&h)
+				encode(&h).to_vec()
 			},
 		}
 	}
@@ -727,7 +726,6 @@ mod tests {
 
 	#[test]
 	fn playpen() {
-		env_logger::init().ok();
 
 		/*let maps = map!{
 			"six-low" => StandardMap{alphabet: Alphabet::Low, min_key: 6, journal_key: 0, count: 1000},
@@ -1040,7 +1038,7 @@ mod tests {
 			let alphabet = b"@QWERTYUIOPASDFGHJKLZXCVBNM[/]^_";
 			for j in 0..4u32 {
 				let key = random_key(alphabet, 5, 1);
-				x.push((key, encode(&j)));
+				x.push((key, encode(&j).to_vec()));
 			}
 			let real = trie_root(x.clone());
 			let mut memdb = MemoryDB::new();

util/src/triehash.rs

@@ -30,7 +30,7 @@ pub fn ordered_trie_root(input: Vec<Vec<u8>>) -> H256 {
 		// optimize it later
 		.into_iter()
 		.enumerate()
-		.fold(BTreeMap::new(), | mut acc, (i, vec) | { acc.insert(rlp::encode(&i), vec); acc })
+		.fold(BTreeMap::new(), | mut acc, (i, vec) | { acc.insert(rlp::encode(&i).to_vec(), vec); acc })
 		// then move them to a vector
 		.into_iter()
 		.map(|(k, v)| (as_nibbles(&k), v) )
@@ -189,7 +189,7 @@ fn hash256rlp(input: &[(Vec<u8>, Vec<u8>)], pre_len: usize, stream: &mut RlpStre
 	// if the slice contains just one item, append the suffix of the key
 	// and then append value
 	if inlen == 1 {
-		stream.append_list(2);
+		stream.begin_list(2);
 		stream.append(&hex_prefix_encode(&key[pre_len..], true));
 		stream.append(&value);
 		return;
@@ -208,7 +208,7 @@ fn hash256rlp(input: &[(Vec<u8>, Vec<u8>)], pre_len: usize, stream: &mut RlpStre
 	// new part of the key to the stream
 	// then recursively append suffixes of all items who had this key
 	if shared_prefix > pre_len {
-		stream.append_list(2);
+		stream.begin_list(2);
 		stream.append(&hex_prefix_encode(&key[pre_len..shared_prefix], false));
 		hash256aux(input, shared_prefix, stream);
 		return;
@@ -216,7 +216,7 @@ fn hash256rlp(input: &[(Vec<u8>, Vec<u8>)], pre_len: usize, stream: &mut RlpStre
 
 	// an item for every possible nibble/suffix
 	// + 1 for data
-	stream.append_list(17);
+	stream.begin_list(17);
 
 	// if first key len is equal to prefix_len, move to next element
 	let mut begin = match pre_len == key.len() {