sync tests

src/eth.rs

@@ -35,7 +35,7 @@ pub struct BlockQueueStatus {
 	pub full: bool,
 }
 
-pub struct TreeRoute;
+pub type TreeRoute = ::blockchain::TreeRoute;
 
 pub type BlockNumber = u32;
 pub type BlockHeader = ::header::Header;
@@ -46,9 +46,9 @@ pub trait BlockChainClient : Sync {
 	fn block(&self, h: &H256) -> Option<Bytes>;
 	fn block_status(&self, h: &H256) -> BlockStatus;
 	fn block_header_at(&self, n: BlockNumber) -> Option<Bytes>;
-	fn block_body_at(&self, h: BlockNumber) -> Option<Bytes>;
-	fn block_at(&self, h: BlockNumber) -> Option<Bytes>;
-	fn block_status_at(&self, h: BlockNumber) -> BlockStatus;
+	fn block_body_at(&self, n: BlockNumber) -> Option<Bytes>;
+	fn block_at(&self, n: BlockNumber) -> Option<Bytes>;
+	fn block_status_at(&self, n: BlockNumber) -> BlockStatus;
 	fn tree_route(&self, from: &H256, to: &H256) -> TreeRoute;
 	fn state_data(&self, h: &H256) -> Option<Bytes>;
 	fn block_receipts(&self, h: &H256) -> Option<Bytes>;

src/genesis.rs

@@ -1,5 +1,6 @@
 use std::io::Read;
 use std::str::FromStr;
+use std::cell::Cell;
 use std::collections::HashMap;
 use rustc_serialize::base64::FromBase64;
 use rustc_serialize::json::Json;
@@ -81,7 +82,8 @@ impl Genesis {
 				let mixhash = H256::from_str(&json["mixhash"].as_string().unwrap()[2..]).unwrap();
 				let nonce = H64::from_str(&json["nonce"].as_string().unwrap()[2..]).unwrap();
 				vec![mixhash.to_vec(), nonce.to_vec()]
-			}
+			},
+			hash: Cell::new(None)
 		};
 
 		let mut state = HashMap::new();

src/header.rs

@@ -1,4 +1,6 @@
+use std::cell::Cell;
 use util::hash::*;
+use util::sha3::*;
 use util::bytes::*;
 use util::uint::*;
 use util::rlp::*;
@@ -28,6 +30,8 @@ pub struct Header {
 
 	pub difficulty: U256,
 	pub seal: Vec<Bytes>,
+
+	pub hash: Cell<Option<H256>>, //TODO: make this private
 }
 
 impl Header {
@@ -50,37 +54,49 @@ impl Header {
 
 			difficulty: ZERO_U256.clone(),
 			seal: vec![],
+			hash: Cell::new(None),
 		}
 	}
 
 	pub fn hash(&self) -> H256 {
-		unimplemented!();
+		let hash = self.hash.get();
+		match hash {
+			Some(h) => h,
+			None => {
+				let mut stream = RlpStream::new();
+				stream.append(self);
+				let h = stream.raw().sha3();
+				self.hash.set(Some(h.clone()));
+				h
+			}
+		}
 	}
 }
 
 impl Decodable for Header {
 	fn decode<D>(decoder: &D) -> Result<Self, DecoderError> where D: Decoder {
-		let d = try!(decoder.as_list());
+		let r = decoder.as_rlp();
 
 		let mut blockheader = Header {
-			parent_hash: try!(Decodable::decode(&d[0])),
-			uncles_hash: try!(Decodable::decode(&d[1])),
-			author: try!(Decodable::decode(&d[2])),
-			state_root: try!(Decodable::decode(&d[3])),
-			transactions_root: try!(Decodable::decode(&d[4])),
-			receipts_root: try!(Decodable::decode(&d[5])),
-			log_bloom: try!(Decodable::decode(&d[6])),
-			difficulty: try!(Decodable::decode(&d[7])),
-			number: try!(Decodable::decode(&d[8])),
-			gas_limit: try!(Decodable::decode(&d[9])),
-			gas_used: try!(Decodable::decode(&d[10])),
-			timestamp: try!(Decodable::decode(&d[11])),
-			extra_data: try!(Decodable::decode(&d[12])),
+			parent_hash: try!(r.val_at(0)),
+			uncles_hash: try!(r.val_at(1)),
+			author: try!(r.val_at(2)),
+			state_root: try!(r.val_at(3)),
+			transactions_root: try!(r.val_at(4)),
+			receipts_root: try!(r.val_at(5)),
+			log_bloom: try!(r.val_at(6)),
+			difficulty: try!(r.val_at(7)),
+			number: try!(r.val_at(8)),
+			gas_limit: try!(r.val_at(9)),
+			gas_used: try!(r.val_at(10)),
+			timestamp: try!(r.val_at(11)),
+			extra_data: try!(r.val_at(12)),
 			seal: vec![],
+			hash: Cell::new(Some(r.raw().sha3()))
 		};
 
-		for i in 13..d.len() {
-			blockheader.seal.push(try!(Decodable::decode(&d[i])));
+		for i in 13..r.item_count() {
+			blockheader.seal.push(try!(r.val_at(i)))
 		}
 
 		Ok(blockheader)

src/sync/chain.rs

@@ -1,7 +1,7 @@
 use std::collections::{HashSet, HashMap};
 use std::cmp::{min, max};
 use std::mem::{replace};
-use util::network::{PeerId, HandlerIo, PacketId};
+use util::network::{PeerId, PacketId};
 use util::hash::{H256};
 use util::bytes::{Bytes};
 use util::uint::{U256};
@@ -10,23 +10,7 @@ use util::rlp::rlptraits::{Stream, View};
 use util::sha3::Hashable;
 use eth::{BlockNumber, BlockChainClient, BlockHeader, BlockStatus, QueueStatus, ImportResult};
 use sync::range_collection::{RangeCollection, ToUsize, FromUsize};
-
-pub struct SyncIo<'s, 'h> where 'h:'s {
-	network: &'s mut HandlerIo<'h>,
-	chain: &'s mut BlockChainClient
-}
-
-impl<'s, 'h> SyncIo<'s, 'h> {
-	pub fn new(network: &'s mut HandlerIo<'h>, chain: &'s mut BlockChainClient) -> SyncIo<'s,'h> {
-		SyncIo {
-			network: network,
-			chain: chain,
-		}
-	}
-	fn disable_peer(&mut self, peer_id: &PeerId) {
-		self.network.disable_peer(*peer_id);
-	}
-}
+use sync::{SyncIo};
 
 impl ToUsize for BlockNumber {
 	fn to_usize(&self) -> usize {
@@ -106,7 +90,6 @@ pub struct SyncStatus {
 enum PeerAsking
 {
 	Nothing,
-	State,
 	BlockHeaders,
 	BlockBodies,
 }
@@ -213,8 +196,8 @@ impl ChainSync {
 		self.starting_block = 0;
 		self.highest_block = 0;
 		self.have_common_block = false;
-		io.chain.clear_queue();
-		self.starting_block = io.chain.info().last_block_number;
+		io.chain().clear_queue();
+		self.starting_block = io.chain().info().last_block_number;
 		self.state = SyncState::NotSynced;
 	}
 
@@ -263,7 +246,7 @@ impl ChainSync {
 			if number > self.highest_block {
 				self.highest_block = number;
 			}
-			match io.chain.block_status(&info.hash()) {
+			match io.chain().block_status(&info.hash()) {
 				BlockStatus::InChain => {
 					self.have_common_block = true;
 					self.last_imported_block = number;
@@ -285,7 +268,7 @@ impl ChainSync {
 						}
 					}
 					let hdr = Header {
-						data: r.at(i).data().to_vec(),
+						data: r.at(i).raw().to_vec(),
 						hash: info.hash(),
 						parent: info.parent_hash,
 					};
@@ -298,7 +281,7 @@ impl ChainSync {
 						//empty body, just mark as downloaded
 						let mut body_stream = RlpStream::new_list(2);
 						body_stream.append_raw(&rlp::EMPTY_LIST_RLP, 1);
-						body_stream.append_raw(&rlp::EMPTY_LIST_RLP, 1);
+						body_stream.append_raw(&rlp::NULL_RLP, 1);
 						self.bodies.insert_item(number, body_stream.out());
 					}
 					else {
@@ -327,8 +310,8 @@ impl ChainSync {
 		for i in 0..item_count {
 			let body: Rlp = r.at(i);
 			let tx = body.at(0);
-			let tx_root = ::util::triehash::ordered_trie_root(tx.iter().map(|r| r.data().to_vec()).collect()); //TODO: get rid of vectors here
-			let uncles = body.at(1).data().sha3();
+			let tx_root = ::util::triehash::ordered_trie_root(tx.iter().map(|r| r.raw().to_vec()).collect()); //TODO: get rid of vectors here
+			let uncles = body.at(1).raw().sha3();
 			let header_id = HeaderId {
 				transactions_root: tx_root,
 				uncles: uncles
@@ -336,7 +319,7 @@ impl ChainSync {
 			match self.header_ids.get(&header_id).map(|n| *n) {
 				Some(n) => {
 					self.header_ids.remove(&header_id);
-					self.bodies.insert_item(n, body.data().to_vec());
+					self.bodies.insert_item(n, body.raw().to_vec());
 				}
 				None =>  {
 					debug!(target: "sync", "Ignored unknown block body");
@@ -351,9 +334,9 @@ impl ChainSync {
 	fn on_peer_new_block(&mut self, io: &mut SyncIo, peer_id: &PeerId, r: &Rlp) {
 		let block_rlp = r.at(0);
 		let header_rlp = block_rlp.at(0);
-		let h = header_rlp.data().sha3();
+		let h = header_rlp.raw().sha3();
 
-		match io.chain.import_block(block_rlp.data()) {
+		match io.chain().import_block(block_rlp.raw()) {
 			ImportResult::AlreadyInChain  => {
 				trace!(target: "sync", "New block already in chain {:?}", h);
 			},
@@ -388,7 +371,7 @@ impl ChainSync {
 		let hashes = r.iter().map(|item| (item.val_at::<H256>(0), item.val_at::<U256>(1)));
 		let mut max_height: U256 = From::from(0);
 		for (h, d) in hashes {
-			match io.chain.block_status(&h) {
+			match io.chain().block_status(&h) {
 				BlockStatus::InChain  => {
 					trace!(target: "sync", "New block hash already in chain {:?}", h);
 				},
@@ -458,7 +441,7 @@ impl ChainSync {
 			(peer.latest.clone(), peer.difficulty.clone())
 		};
 
-		let td = io.chain.info().pending_total_difficulty;
+		let td = io.chain().info().pending_total_difficulty;
 		let syncing_difficulty = max(self.syncing_difficulty, td);
 		if force || peer_difficulty > syncing_difficulty {
 			// start sync
@@ -476,7 +459,7 @@ impl ChainSync {
 	fn request_blocks(&mut self, io: &mut SyncIo, peer_id: &PeerId) {
 		self.clear_peer_download(peer_id);
 
-		if io.chain.queue_status().full {
+		if io.chain().queue_status().full {
 			self.pause_sync();
 			return;
 		}
@@ -511,7 +494,7 @@ impl ChainSync {
 			let mut start = 0usize;
 			if !self.have_common_block {
 				// download backwards until common block is found 1 header at a time
-				start = io.chain.info().last_block_number as usize;
+				start = io.chain().info().last_block_number as usize;
 				if !self.headers.is_empty() {
 					start = min(start, self.headers.range_iter().next().unwrap().0 as usize - 1);
 				}
@@ -585,7 +568,7 @@ impl ChainSync {
 				block_rlp.append_raw(&headers.1[i].data, 1);
 				block_rlp.append_raw(&bodies.1[i], 2);
 				let h = &headers.1[i].hash;
-				match io.chain.import_block(&block_rlp.out()) {
+				match io.chain().import_block(&block_rlp.out()) {
 					ImportResult::AlreadyInChain  => {
 						trace!(target: "sync", "Block already in chain {:?}", h);
 						self.last_imported_block = headers.0 + i as BlockNumber;
@@ -676,7 +659,7 @@ impl ChainSync {
 				warn!(target:"sync", "Asking {:?} while requesting {:?}", asking, peer.asking);
 			}
 		}
-		match sync.network.send(*peer_id, packet_id, packet) {
+		match sync.send(*peer_id, packet_id, packet) {
 			Err(e) => {
 				warn!(target:"sync", "Error sending request: {:?}", e);
 				sync.disable_peer(peer_id);
@@ -694,13 +677,20 @@ impl ChainSync {
 
 	fn send_status(&mut self, io: &mut SyncIo, peer_id: &PeerId) {
 		let mut packet = RlpStream::new_list(5);
-		let chain = io.chain.info();
+		let chain = io.chain().info();
 		packet.append(&(PROTOCOL_VERSION as u32));
 		packet.append(&0u32); //TODO: network id
 		packet.append(&chain.total_difficulty);
 		packet.append(&chain.last_block_hash);
 		packet.append(&chain.genesis_hash);
-		self.send_request(io, peer_id, PeerAsking::State, STATUS_PACKET, packet.out());
+		//TODO: handle timeout for status request
+		match io.send(*peer_id, STATUS_PACKET, packet.out()) {
+			Err(e) => {
+				warn!(target:"sync", "Error sending status request: {:?}", e);
+				io.disable_peer(peer_id);
+			}
+			Ok(_) => {  }
+		}
 	}
 
 	fn return_block_headers(&self, io: &mut SyncIo, r: &Rlp) {
@@ -709,12 +699,12 @@ impl ChainSync {
 		let max_headers: usize = r.val_at(1);
 		let skip: usize = r.val_at(2);
 		let reverse: bool = r.val_at(3);
-		let last = io.chain.info().last_block_number;
+		let last = io.chain().info().last_block_number;
 		let mut number = if r.at(0).size() == 32 {
 			// id is a hash
 			let hash: H256 = r.val_at(0);
 			trace!(target: "sync", "GetBlockHeaders (hash: {}, max: {}, skip: {}, reverse:{})", hash, max_headers, skip, reverse);
-			match io.chain.block_header(&hash) {
+			match io.chain().block_header(&hash) {
 				Some(hdr) => From::from(rlp::decode::<BlockHeader>(&hdr).number),
 				None => last
 			}
@@ -729,7 +719,7 @@ impl ChainSync {
 		let mut count = 0;
 		let mut data = Bytes::new();
 		while number < last && number > 1 && count < max_count {
-			match io.chain.block_header_at(number) {
+			match io.chain().block_header_at(number) {
 				Some(mut hdr) => {
 					data.append(&mut hdr);
 					count += 1;
@@ -745,7 +735,7 @@ impl ChainSync {
 		}
 		let mut rlp = RlpStream::new_list(count as usize);
 		rlp.append_raw(&data, count as usize);
-		io.network.respond(BLOCK_HEADERS_PACKET, rlp.out()).unwrap_or_else(|e|
+		io.respond(BLOCK_HEADERS_PACKET, rlp.out()).unwrap_or_else(|e|
 			debug!(target: "sync", "Error sending headers: {:?}", e));
 	}
 
@@ -759,7 +749,7 @@ impl ChainSync {
 		let mut added = 0usize;
 		let mut data = Bytes::new();
 		for i in 0..count {
-			match io.chain.block_body(&r.val_at::<H256>(i)) {
+			match io.chain().block_body(&r.val_at::<H256>(i)) {
 				Some(mut hdr) => {
 					data.append(&mut hdr);
 					added += 1;
@@ -769,7 +759,7 @@ impl ChainSync {
 		}
 		let mut rlp = RlpStream::new_list(added);
 		rlp.append_raw(&data, added);
-		io.network.respond(BLOCK_BODIES_PACKET, rlp.out()).unwrap_or_else(|e|
+		io.respond(BLOCK_BODIES_PACKET, rlp.out()).unwrap_or_else(|e|
 			debug!(target: "sync", "Error sending headers: {:?}", e));
 	}
 
@@ -783,7 +773,7 @@ impl ChainSync {
 		let mut added = 0usize;
 		let mut data = Bytes::new();
 		for i in 0..count {
-			match io.chain.state_data(&r.val_at::<H256>(i)) {
+			match io.chain().state_data(&r.val_at::<H256>(i)) {
 				Some(mut hdr) => {
 					data.append(&mut hdr);
 					added += 1;
@@ -793,7 +783,7 @@ impl ChainSync {
 		}
 		let mut rlp = RlpStream::new_list(added);
 		rlp.append_raw(&data, added);
-		io.network.respond(NODE_DATA_PACKET, rlp.out()).unwrap_or_else(|e|
+		io.respond(NODE_DATA_PACKET, rlp.out()).unwrap_or_else(|e|
 			debug!(target: "sync", "Error sending headers: {:?}", e));
 	}
 
@@ -807,7 +797,7 @@ impl ChainSync {
 		let mut added = 0usize;
 		let mut data = Bytes::new();
 		for i in 0..count {
-			match io.chain.block_receipts(&r.val_at::<H256>(i)) {
+			match io.chain().block_receipts(&r.val_at::<H256>(i)) {
 				Some(mut hdr) => {
 					data.append(&mut hdr);
 					added += 1;
@@ -817,7 +807,7 @@ impl ChainSync {
 		}
 		let mut rlp = RlpStream::new_list(added);
 		rlp.append_raw(&data, added);
-		io.network.respond(RECEIPTS_PACKET, rlp.out()).unwrap_or_else(|e|
+		io.respond(RECEIPTS_PACKET, rlp.out()).unwrap_or_else(|e|
 			debug!(target: "sync", "Error sending headers: {:?}", e));
 	}
 
@@ -834,7 +824,7 @@ impl ChainSync {
 			NEW_BLOCK_HASHES_PACKET => self.on_peer_new_hashes(io, peer, &rlp),
 			GET_NODE_DATA_PACKET => self.return_node_data(io, &rlp),
 			GET_RECEIPTS_PACKET => self.return_receipts(io, &rlp),
-			_ => debug!(target: "sync", "Unkown packet {}", packet_id)
+			_ => debug!(target: "sync", "Unknown packet {}", packet_id)
 		}
 	}
 

src/sync/mod.rs

@@ -1,7 +1,7 @@
 use std::sync::{Arc};
 use eth::{BlockChainClient};
-use util::network::{ProtocolHandler, NetworkService, HandlerIo, TimerToken, PeerId};
-use sync::chain::{ChainSync, SyncIo};
+use util::network::{ProtocolHandler, NetworkService, HandlerIo, TimerToken, PeerId, PacketId, Error as NetworkError};
+use sync::chain::{ChainSync};
 
 mod chain;
 mod range_collection;
@@ -9,7 +9,6 @@ mod range_collection;
 #[cfg(test)]
 mod tests;
 
-
 pub fn new(_service: &mut NetworkService, eth_client: Arc<BlockChainClient+Send+Sized>) -> EthSync {
 	EthSync {
 		chain: eth_client,
@@ -17,6 +16,45 @@ pub fn new(_service: &mut NetworkService, eth_client: Arc<BlockChainClient+Send+
 	}
 }
 
+pub trait SyncIo {
+	fn disable_peer(&mut self, peer_id: &PeerId);
+	fn respond(&mut self, packet_id: PacketId, data: Vec<u8>) -> Result<(), NetworkError>;
+	fn send(&mut self, peer_id: PeerId, packet_id: PacketId, data: Vec<u8>) -> Result<(), NetworkError>;
+	fn chain<'s>(&'s mut self) -> &'s mut BlockChainClient;
+}
+
+pub struct NetSyncIo<'s, 'h> where 'h:'s {
+	network: &'s mut HandlerIo<'h>,
+	chain: &'s mut BlockChainClient
+}
+
+impl<'s, 'h> NetSyncIo<'s, 'h> {
+	pub fn new(network: &'s mut HandlerIo<'h>, chain: &'s mut BlockChainClient) -> NetSyncIo<'s,'h> {
+		NetSyncIo {
+			network: network,
+			chain: chain,
+		}
+	}
+}
+
+impl<'s, 'h> SyncIo for NetSyncIo<'s, 'h> {
+	fn disable_peer(&mut self, peer_id: &PeerId) {
+		self.network.disable_peer(*peer_id);
+	}
+
+	fn respond(&mut self, packet_id: PacketId, data: Vec<u8>) -> Result<(), NetworkError>{
+		self.network.respond(packet_id, data)
+	}
+
+	fn send(&mut self, peer_id: PeerId, packet_id: PacketId, data: Vec<u8>) -> Result<(), NetworkError>{
+		self.network.send(peer_id, packet_id, data)
+	}
+
+	fn chain<'a>(&'a mut self) -> &'a mut BlockChainClient {
+		self.chain
+	}
+}
+
 pub struct EthSync {
 	chain: Arc<BlockChainClient+Send+Sized>,
 	sync: ChainSync
@@ -34,34 +72,34 @@ impl EthSync {
 	}
 
 	pub fn stop_network(&mut self, io: &mut HandlerIo) {
-		self.sync.abort(&mut SyncIo::new(io, Arc::get_mut(&mut self.chain).unwrap()));
+		self.sync.abort(&mut NetSyncIo::new(io, Arc::get_mut(&mut self.chain).unwrap()));
 	}
 
 	pub fn start_network(&mut self, io: &mut HandlerIo) {
-		self.sync.restart(&mut SyncIo::new(io, Arc::get_mut(&mut self.chain).unwrap()));
+		self.sync.restart(&mut NetSyncIo::new(io, Arc::get_mut(&mut self.chain).unwrap()));
 	}
 }
 
 impl ProtocolHandler for EthSync {
 	fn initialize(&mut self, io: &mut HandlerIo) {
-		self.sync.restart(&mut SyncIo::new(io, Arc::get_mut(&mut self.chain).unwrap()));
+		self.sync.restart(&mut NetSyncIo::new(io, Arc::get_mut(&mut self.chain).unwrap()));
 		io.register_timer(1000).unwrap();
 	}
 
 	fn read(&mut self, io: &mut HandlerIo, peer: &PeerId, packet_id: u8, data: &[u8]) {
-		self.sync.on_packet(&mut SyncIo::new(io, Arc::get_mut(&mut self.chain).unwrap()), peer, packet_id, data);
+		self.sync.on_packet(&mut NetSyncIo::new(io, Arc::get_mut(&mut self.chain).unwrap()), peer, packet_id, data);
 	}
 
 	fn connected(&mut self, io: &mut HandlerIo, peer: &PeerId) {
-		self.sync.on_peer_connected(&mut SyncIo::new(io, Arc::get_mut(&mut self.chain).unwrap()), peer);
+		self.sync.on_peer_connected(&mut NetSyncIo::new(io, Arc::get_mut(&mut self.chain).unwrap()), peer);
 	}
 
 	fn disconnected(&mut self, io: &mut HandlerIo, peer: &PeerId) {
-		self.sync.on_peer_aborting(&mut SyncIo::new(io, Arc::get_mut(&mut self.chain).unwrap()), peer);
+		self.sync.on_peer_aborting(&mut NetSyncIo::new(io, Arc::get_mut(&mut self.chain).unwrap()), peer);
 	}
 
 	fn timeout(&mut self, io: &mut HandlerIo, _timer: TimerToken) {
-		self.sync.maintain_sync(&mut SyncIo::new(io, Arc::get_mut(&mut self.chain).unwrap()));
+		self.sync.maintain_sync(&mut NetSyncIo::new(io, Arc::get_mut(&mut self.chain).unwrap()));
 	}
 }
 

src/sync/tests.rs

@@ -1,13 +1,285 @@
-use std::collections::HashMap;
+use std::collections::{HashMap, VecDeque};
 use util::bytes::Bytes;
-use util::hash::H256;
+use util::hash::{H256, FixedHash};
+use util::uint::{U256};
+use util::sha3::Hashable;
+use util::rlp::{self, Rlp, RlpStream, View, Stream};
+use util::network::{PeerId, PacketId, Error as NetworkError};
+use eth::{BlockChainClient, BlockStatus, BlockNumber, TreeRoute, BlockQueueStatus, BlockChainInfo, ImportResult, BlockHeader, QueueStatus};
+use sync::{SyncIo};
+use sync::chain::{ChainSync};
 
 struct TestBlockChainClient {
 	blocks: Vec<Bytes>,
  	hashes: HashMap<H256, usize>,
+	genesis_hash: H256,
+	last_hash: H256,
+	difficulty: U256
+}
+
+impl TestBlockChainClient {
+	fn new() -> TestBlockChainClient {
+
+		let mut client = TestBlockChainClient {
+			blocks: Vec::new(),
+			hashes: HashMap::new(),
+			genesis_hash: H256::new(),
+			last_hash: H256::new(),
+			difficulty: From::from(0),
+		};
+		client.add_blocks(1, true); // add genesis block
+		client.genesis_hash = client.last_hash;
+		client
+	}
+
+	pub fn add_blocks(&mut self, count: usize, empty: bool) {
+		for n in self.blocks.len()..(self.blocks.len() + count) {
+			let mut header = BlockHeader::new();
+			header.difficulty = From::from(n);
+			header.parent_hash = self.last_hash;
+			header.number = From::from(n);
+			let mut uncles = RlpStream::new_list(if empty {0} else {1});
+			if !empty {
+				uncles.append(&H256::random());
+				header.uncles_hash = uncles.raw().sha3();
+			}
+			let mut rlp = RlpStream::new_list(3);
+			rlp.append(&header);
+			rlp.append_raw(uncles.raw(), 1);
+			rlp.append_raw(&rlp::NULL_RLP, 1);
+			self.import_block(rlp.raw());
+		}
+	}
+}
+
+impl BlockChainClient for TestBlockChainClient {
+	fn block_header(&self, h: &H256) -> Option<Bytes> {
+		self.hashes.get(h).and_then(|i| self.block_header_at(*i as BlockNumber))
+	}
+
+	fn block_body(&self, h: &H256) -> Option<Bytes> {
+		self.hashes.get(h).and_then(|i| self.block_body_at(*i as BlockNumber))
+	}
+
+	fn block(&self, h: &H256) -> Option<Bytes> {
+		self.hashes.get(h).map(|i| self.blocks[*i].clone())
+	}
+
+	fn block_status(&self, h: &H256) -> BlockStatus {
+		self.hashes.get(h).map(|i| self.block_status_at(*i as BlockNumber)).unwrap_or(BlockStatus::Unknown)
+	}
+
+	fn block_header_at(&self, n: BlockNumber) -> Option<Bytes> {
+		self.blocks.get(n as usize).map(|r| Rlp::new(r).at(0).raw().to_vec())
+	}
+
+	fn block_body_at(&self, n: BlockNumber) -> Option<Bytes> {
+		self.blocks.get(n as usize).map(|r| {
+			let mut stream = RlpStream::new_list(2);
+			stream.append_raw(Rlp::new(&r).at(1).raw(), 1);
+			stream.append_raw(Rlp::new(&r).at(2).raw(), 1);
+			stream.out()
+		})
+	}
+
+	fn block_at(&self, n: BlockNumber) -> Option<Bytes> {
+		self.blocks.get(n as usize).map(|b| b.clone())
+	}
+
+	fn block_status_at(&self, n: BlockNumber) -> BlockStatus {
+		if (n as usize) < self.blocks.len() {
+			BlockStatus::InChain
+		} else {
+			BlockStatus::Unknown
+		}
+	}
+
+	fn tree_route(&self, _from: &H256, _to: &H256) -> TreeRoute {
+		TreeRoute {
+			blocks: Vec::new(),
+			ancestor: H256::new(),
+			index: 0
+		}
+	}
+
+	fn state_data(&self, _h: &H256) -> Option<Bytes> {
+		None
+	}
+
+	fn block_receipts(&self, _h: &H256) -> Option<Bytes> {
+		None
+	}
+
+	fn import_block(&mut self, b: &[u8]) -> ImportResult {
+		let header = Rlp::new(&b).val_at::<BlockHeader>(0);
+		if header.number != From::from(self.blocks.len()) {
+			panic!("Unexpected block number");
+		}
+		if !self.blocks.is_empty() {
+			let parent = Rlp::new(self.blocks.last().unwrap()).val_at::<BlockHeader>(0);
+			if header.parent_hash != parent.hash() {
+				panic!("Unexpected block header");
+			}
+		}
+		self.difficulty = self.difficulty + header.difficulty;
+		self.last_hash = header.hash();
+		self.hashes.insert(header.hash(), self.blocks.len());
+		self.blocks.push(b.to_vec());
+		ImportResult::Queued(QueueStatus::Known)
+	}
+
+	fn queue_status(&self) -> BlockQueueStatus {
+		BlockQueueStatus {
+			full: false,
+		}
+	}
+
+	fn clear_queue(&mut self) {
+	}
+
+	fn info(&self) -> BlockChainInfo {
+		BlockChainInfo {
+			total_difficulty: self.difficulty,
+			pending_total_difficulty: self.difficulty,
+			genesis_hash: self.genesis_hash,
+			last_block_hash: self.last_hash,
+			last_block_number: self.blocks.len() as BlockNumber - 1,
+		}
+	}
+}
+
+struct TestIo<'p> {
+	chain: &'p mut TestBlockChainClient,
+	queue: &'p mut VecDeque<TestPacket>,
+	sender: Option<PeerId>,
+}
+
+impl<'p> TestIo<'p> {
+	fn new(chain: &'p mut TestBlockChainClient, queue: &'p mut VecDeque<TestPacket>, sender: Option<PeerId>) -> TestIo<'p> {
+		TestIo {
+			chain: chain,
+			queue: queue,
+			sender: sender
+		}
+	}
+}
+
+impl<'p> SyncIo for TestIo<'p> {
+	fn disable_peer(&mut self, _peer_id: &PeerId) {
+	}
+
+	fn respond(&mut self, packet_id: PacketId, data: Vec<u8>) -> Result<(), NetworkError> {
+		self.queue.push_back(TestPacket {
+			data: data,
+			packet_id: packet_id,
+			recipient: self.sender.unwrap()
+		});
+		Ok(())
+	}
+
+	fn send(&mut self, peer_id: PeerId, packet_id: PacketId, data: Vec<u8>) -> Result<(), NetworkError> {
+		self.queue.push_back(TestPacket {
+			data: data,
+			packet_id: packet_id,
+			recipient: peer_id,
+		});
+		Ok(())
+	}
+
+	fn chain<'a>(&'a mut self) -> &'a mut BlockChainClient {
+		self.chain
+	}
+}
+
+struct TestPacket {
+	data: Bytes,
+	packet_id: PacketId,
+	recipient: PeerId,
+}
+
+struct TestPeer {
+	chain: TestBlockChainClient,
+	sync: ChainSync,
+	queue: VecDeque<TestPacket>,
+}
+
+struct TestNet {
+	peers: Vec<TestPeer>
+}
+
+impl TestNet {
+	pub fn new(n: usize) -> TestNet {
+		let mut net = TestNet {
+			peers: Vec::new(),
+		};
+		for _ in 0..n {
+			net.peers.push(TestPeer {
+				chain: TestBlockChainClient::new(),
+				sync: ChainSync::new(),
+				queue: VecDeque::new(),
+			});
+		}
+		net
+	}
+
+	pub fn peer(&mut self, i: usize) -> &mut TestPeer {
+		self.peers.get_mut(i).unwrap()
+	}
+
+	pub fn start(&mut self) {
+		for peer in 0..self.peers.len() {
+			for client in 0..self.peers.len() {
+				if peer != client {
+					let mut p = self.peers.get_mut(peer).unwrap();
+					p.sync.on_peer_connected(&mut TestIo::new(&mut p.chain, &mut p.queue, Some(client as PeerId)), &(client as PeerId));
+				}
+			}
+		}
+	}
+
+	pub fn sync_step(&mut self) {
+		for peer in 0..self.peers.len() {
+			match self.peers[peer].queue.pop_front() {
+				Some(packet) => {
+					let mut p = self.peers.get_mut(packet.recipient).unwrap();
+					p.sync.on_packet(&mut TestIo::new(&mut p.chain, &mut p.queue, Some(peer as PeerId)), &(peer as PeerId), packet.packet_id, &packet.data);
+				},
+				None => {}
+			}
+			let mut p = self.peers.get_mut(peer).unwrap();
+			p.sync.maintain_sync(&mut TestIo::new(&mut p.chain, &mut p.queue, None));
+		}
+	}
+
+	pub fn sync(&mut self) {
+		self.start();
+		while !self.done() {
+			self.sync_step()
+		}
+	}
+
+	pub fn done(&self) -> bool {
+		self.peers.iter().all(|p| p.queue.is_empty())
+	}
 }
 
 
 #[test]
-fn full_sync() {
+fn full_sync_two_peers() {
+	let mut net = TestNet::new(3);
+	net.peer(1).chain.add_blocks(1000, false);
+	net.peer(2).chain.add_blocks(1000, false);
+	net.sync();
+	assert_eq!(net.peer(0).chain.block_at(50000), net.peer(1).chain.block_at(50000));
+}
+
+#[test]
+fn full_sync_empty_blocks() {
+	let mut net = TestNet::new(3);
+	for n in 0..200 {
+		net.peer(1).chain.add_blocks(5, n % 2 == 0);
+		net.peer(2).chain.add_blocks(5, n % 2 == 0);
+	}
+	net.sync();
+	assert_eq!(net.peer(0).chain.block_at(50000), net.peer(1).chain.block_at(50000));
 }