syncing code done

src/eth.rs

@@ -13,6 +13,14 @@ pub enum BlockStatus {
 	InChain,
 	Queued(QueueStatus),
 	Bad,
+	Unknown,
+}
+
+pub enum ImportResult {
+	Queued(QueueStatus),
+	AlreadyInChain,
+	AlreadyQueued(QueueStatus),
+	Bad,
 }
 
 pub struct BlockChainInfo {
@@ -30,16 +38,18 @@ pub type BlockNumber = u32;
 pub type BlockHeader = ::header::Header;
 
 pub trait BlockChainClient : Sync {
-	fn block_header(&self, h: &H256) -> Option<BlockHeader>;
+	fn block_header(&self, h: &H256) -> Option<Bytes>;
 	fn block_body(&self, h: &H256) -> Option<Bytes>;
 	fn block(&self, h: &H256) -> Option<Bytes>;
 	fn block_status(&self, h: &H256) -> BlockStatus;
-	fn block_header_at(&self, n: BlockNumber) -> Option<BlockHeader>;
+	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) -> Option<Bytes>;
+	fn block_status_at(&self, h: BlockNumber) -> BlockStatus;
 	fn tree_route(&self, from: &H256, to: &H256) -> TreeRoute;
-	fn import_block(&mut self, b: Bytes) -> BlockStatus;
+	fn state_data(&self, h: &H256) -> Option<Bytes>;
+	fn block_receipts(&self, h: &H256) -> Option<Bytes>;
+	fn import_block(&mut self, b: &[u8]) -> ImportResult;
 	fn queue_stats(&self) -> BlockQueueStats;
 	fn clear_queue(&mut self) -> BlockQueueStats;
 	fn info(&self) -> BlockChainInfo;

src/header.rs

@@ -52,6 +52,10 @@ impl Header {
 			seal: vec![],
 		}
 	}
+
+	pub fn hash(&self) -> H256 {
+		unimplemented!();
+	}
 }
 
 impl Decodable for Header {

src/sync/chain.rs

@@ -1,14 +1,15 @@
 use std::collections::{HashSet, HashMap};
 use std::cmp::{min, max};
-use std::ops::{Add, Sub};
+use std::ops::{Add, Sub, Range};
 use std::mem::{replace};
 use util::network::{PeerId, HandlerIo, PacketId};
 use util::hash::{H256};
 use util::bytes::{Bytes};
 use util::uint::{U256};
-use util::rlp::{Rlp, RlpStream};
+use util::rlp::{Rlp, RlpStream, self}; //TODO: use UntrustedRlp
 use util::rlp::rlptraits::{Stream, View};
-use eth::{BlockNumber, BlockChainClient};
+use util::sha3::Hashable;
+use eth::{BlockNumber, BlockChainClient, BlockHeader, BlockStatus, QueueStatus, ImportResult};
 
 pub struct SyncIo<'s, 'h> where 'h:'s {
 	network: &'s mut HandlerIo<'h>,
@@ -16,11 +17,23 @@ pub struct SyncIo<'s, 'h> where 'h:'s {
 }
 
 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);
 	}
 }
 
+const PROTOCOL_VERSION: u8 = 63u8;
+const MAX_BODIES_TO_SEND: usize = 256;
+const MAX_HEADERS_TO_SEND: usize = 1024;
+const MAX_NODE_DATA_TO_SEND: usize = 1024;
+const MAX_RECEIPTS_TO_SEND: usize = 1024;
+
 const STATUS_PACKET: u8 = 0x00;
 const NEW_BLOCK_HASHES_PACKET: u8 = 0x01;
 const TRANSACTIONS_PACKET: u8 = 0x02;
@@ -125,7 +138,6 @@ pub struct ChainSync {
 
 
 impl ChainSync {
-
 	pub fn new(io: &mut SyncIo) -> ChainSync {
 		let mut sync = ChainSync {
 			state: SyncState::NotSynced,
@@ -195,7 +207,7 @@ impl ChainSync {
 	}
 
 	/// Called by peer to report status
-	pub fn on_peer_status(&mut self, io: &mut SyncIo, peer_id: &PeerId, r: &Rlp) {
+	fn on_peer_status(&mut self, io: &mut SyncIo, peer_id: &PeerId, r: &Rlp) {
 		let peer = PeerInfo {
 			protocol_version: r.val_at(0),
 			network_id: r.val_at(1),
@@ -213,7 +225,7 @@ impl ChainSync {
 	}
 
 	/// Called by peer once it has new block headers during sync
-	pub fn on_peer_block_headers(&mut self, io: &mut SyncIo, peer_id: &PeerId,  r: &Rlp) {
+	fn on_peer_block_headers(&mut self, io: &mut SyncIo, peer_id: &PeerId,  r: &Rlp) {
 		let item_count = r.item_count();
 		trace!(target: "sync", "BlockHeaders ({} entries)", item_count);
 		self.clear_peer_download(peer_id);
@@ -225,36 +237,193 @@ impl ChainSync {
 			trace!(target: "sync", "Ignored block headers while waiting");
 			return;
 		}
+
+		for i in 0..item_count {
+			let info: BlockHeader = r.val_at(i);
+			let number = BlockNumber::from(info.number);
+			if number <= self.last_imported_block || self.headers.have_item(&number) {
+				trace!(target: "sync", "Skipping existing block header");
+				continue;
+			}
+			if number > self.highest_block {
+				self.highest_block = number;
+			}
+			match io.chain.block_status(&info.hash()) {
+				BlockStatus::InChain => {
+					self.have_common_block = true;
+					self.last_imported_block = number;
+				},
+				_ => {
+					if self.have_common_block {
+						//validate chain
+						if self.headers.find_item(&(number - 1)).map_or(false, |p| p.hash != info.parent_hash) {
+							// mismatching parent id, delete the previous block and don't add this one
+							// TODO: lower peer rating
+							debug!(target: "sync", "Mismatched block header {} {}", number, info.hash());
+							self.remove_downloaded_blocks(number - 1);
+							continue;
+						}
+						if self.headers.find_item(&(number + 1)).map_or(false, |p| p.parent != info.hash()) {
+							// mismatching parent id for the next block, clear following headers
+							debug!(target: "sync", "Mismatched block header {}", number + 1);
+							self.remove_downloaded_blocks(number + 1);
+						}
+					}
+					let hdr = Header {
+						data: r.at(i).data().to_vec(),
+						hash: info.hash(),
+						parent: info.parent_hash,
+					};
+					self.headers.insert_item(number, hdr);
+					let header_id = HeaderId {
+						transactions_root: info.transactions_root,
+						uncles: info.uncles_hash
+					};
+					if header_id.transactions_root == rlp::SHA3_NULL_RLP && header_id.uncles == rlp::SHA3_EMPTY_LIST_RLP {
+						//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);
+						self.bodies.insert_item(number, body_stream.out());
+					}
+					else {
+						self.header_ids.insert(header_id, number);
+					}
+				}
+			}
+			self.collect_blocks(io);
+			self.continue_sync(io);
+		}
 	}
 
 	/// Called by peer once it has new block bodies
-	pub fn on_peer_block_bodies(&mut self, io: &mut SyncIo, peer: &PeerId, r: &Rlp) {
+	fn on_peer_block_bodies(&mut self, io: &mut SyncIo, peer_id: &PeerId, r: &Rlp) {
+		let item_count = r.item_count();
+		trace!(target: "sync", "BlockBodies ({} entries)", item_count);
+		self.clear_peer_download(peer_id);
+		if self.state != SyncState::Blocks && self.state != SyncState::NewBlocks && self.state != SyncState::Waiting {
+			trace!(target: "sync", "Ignored unexpected block bodies");
+			return;
+		}
+		if self.state  == SyncState::Waiting {
+			trace!(target: "sync", "Ignored block bodies while waiting");
+			return;
+		}
+		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 header_id = HeaderId {
+				transactions_root: tx_root,
+				uncles: uncles
+			};
+			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());
+				}
+				None =>  {
+					debug!(target: "sync", "Ignored unknown block body");
+				}
+			}
+		}
+		self.collect_blocks(io);
+		self.continue_sync(io);
 	}
 
 	/// Called by peer once it has new block bodies
-	pub fn on_peer_new_block(&mut self, io: &mut SyncIo, peer: &PeerId, r: &Rlp) {
+	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();
+
+		match io.chain.import_block(block_rlp.data()) {
+			ImportResult::AlreadyInChain  => {
+				trace!(target: "sync", "New block already in chain {:?}", h);
+			},
+			ImportResult::AlreadyQueued(_)  => {
+				trace!(target: "sync", "New block already queued {:?}", h);
+			},
+			ImportResult::Queued(QueueStatus::Known) => {
+				trace!(target: "sync", "New block queued {:?}", h);
+			},
+			ImportResult::Queued(QueueStatus::Unknown) => {
+				trace!(target: "sync", "New block unknown {:?}", h);
+				//TODO: handle too many unknown blocks
+				let difficulty: U256 = r.val_at(1);
+				let peer_difficulty = self.peers.get_mut(&peer_id).expect("ChainSync: unknown peer").difficulty;
+				if difficulty > peer_difficulty {
+					trace!(target: "sync", "Received block {:?}  with no known parent. Peer needs syncing...", h);
+					self.sync_peer(io, peer_id, true);
+				}
+			},
+			ImportResult::Bad =>{
+				debug!(target: "sync", "Bad new block {:?}", h);
+				io.disable_peer(peer_id);
+			}
+		}
 	}
 
-	pub fn on_peer_new_hashes(&mut self, io: &mut SyncIo, peer: &PeerId, r: &Rlp) {
+	fn on_peer_new_hashes(&mut self, io: &mut SyncIo, peer_id: &PeerId, r: &Rlp) {
+		if self.peers.get_mut(&peer_id).expect("ChainSync: unknown peer").asking != PeerAsking::Nothing {
+			trace!(target: "sync", "Ignoring new hashes since we're already downloading.");
+			return;
+		}
+		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) {
+				BlockStatus::InChain  => {
+					trace!(target: "sync", "New block hash already in chain {:?}", h);
+				},
+				BlockStatus::Queued(_) => {
+					trace!(target: "sync", "New hash block already queued {:?}", h);
+				},
+				BlockStatus::Unknown => {
+					trace!(target: "sync", "New unknown block hash {:?}", h);
+					if d > max_height {
+						let peer = self.peers.get_mut(&peer_id).expect("ChainSync: unknown peer");
+						peer.latest = h.clone();
+						max_height = d;
+					}
+				},
+				BlockStatus::Bad =>{
+					debug!(target: "sync", "Bad new block hash {:?}", h);
+					io.disable_peer(peer_id);
+					return;
+				}
+			}
+		}
 	}
 
 	/// Called by peer when it is disconnecting
-	pub fn on_peer_aborting(&mut self, peer: &PeerId) {
+	pub fn on_peer_aborting(&mut self, io: &mut SyncIo, peer: &PeerId) {
+		self.clear_peer_download(peer);
+		self.continue_sync(io);
+	}
+
+	pub fn on_peer_connected(&mut self, io: &mut SyncIo, peer: &PeerId) {
+		self.send_status(io, peer);
 	}
 
 	/// Resume downloading after witing state
-	fn continue_sync(&mut self) {
+	fn continue_sync(&mut self, io: &mut SyncIo) {
+		let peers: Vec<PeerId> = self.peers.keys().map(|k| *k).collect();
+		for p in peers {
+			self.sync_peer(io, &p, false);
+		}
 	}
 
 	/// Called after all blocks have been donloaded
 	fn complete_sync(&mut self) {
+		self.reset();
+		self.state = SyncState::Idle;
 	}
 
 	/// Enter waiting state
 	fn pause_sync(&mut self) {
-	}
-
-	fn reset_sync(&mut self)  {
+		self.state = SyncState::Waiting;
 	}
 
 	fn sync_peer(&mut self, io: &mut SyncIo,  peer_id: &PeerId, force: bool) {
@@ -367,11 +536,90 @@ impl ChainSync {
 		}
 	}
 
-	fn clear_peer_download(&mut self, peer: &PeerId) {
+	fn clear_peer_download(&mut self, peer_id: &PeerId) {
+		let peer = self.peers.get_mut(&peer_id).expect("ChainSync: unknown peer");
+		for b in &peer.asking_blocks {
+			self.downloading_headers.remove(&b);
+			self.downloading_bodies.remove(&b);
+		}
+		peer.asking_blocks.clear();
 	}
-	fn clear_all_download(&mut self) {
+
+	fn collect_blocks(&mut self, io: &mut SyncIo) {
+		if !self.have_common_block || self.headers.is_empty() || self.bodies.is_empty() {
+			return;
+		}
+
+		let mut restart = false;
+		// merge headers and bodies
+		{
+			let mut headers = self.headers.last().unwrap();
+			let mut bodies = self.bodies.last().unwrap();
+			if headers.0 != bodies.0 || headers.0 != self.last_imported_block + 1 {
+				return;
+			}
+
+			for i in 0..min(headers.1.len(), bodies.1.len()) {
+				let mut block_rlp = RlpStream::new_list(3);
+				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()) {
+					ImportResult::AlreadyInChain  => {
+						trace!(target: "sync", "Block already in chain {:?}", h);
+						self.last_imported_block = headers.0 + i as BlockNumber;
+					},
+					ImportResult::AlreadyQueued(_)  => {
+						trace!(target: "sync", "Block already queued {:?}", h);
+						self.last_imported_block = headers.0 + i as BlockNumber;
+					},
+					ImportResult::Queued(QueueStatus::Known) => {
+						trace!(target: "sync", "Block queued {:?}", h);
+						self.last_imported_block = headers.0 + i as BlockNumber;
+					},
+					ImportResult::Queued(QueueStatus::Unknown) => {
+						panic!("Queued out of order block");
+					},
+					ImportResult::Bad =>{
+						debug!(target: "sync", "Bad block {:?}", h);
+						restart = true;
+					}
+				}
+			}
+		}
+
+		if restart {
+			self.restart(io);
+			return;
+		}
+
+		self.headers.remove_head(&self.last_imported_block);
+		self.bodies.remove_head(&self.last_imported_block);
+
+		if self.headers.is_empty() {
+			assert!(self.bodies.is_empty());
+			self.complete_sync();
+		}
 	}
-	fn collect_blocks(&mut self) {
+
+	fn remove_downloaded_blocks(&mut self, start: BlockNumber) {
+		for n in self.headers.get_tail(&start) {
+			match self.headers.find_item(&n) {
+				Some(ref header_data) => {
+					let header_to_delete: BlockHeader = rlp::decode(&header_data.data);
+					let header_id = HeaderId {
+						transactions_root: header_to_delete.transactions_root,
+						uncles: header_to_delete.uncles_hash
+					};
+					self.header_ids.remove(&header_id);
+				},
+				None => {}
+			}
+			self.downloading_bodies.remove(&n);
+			self.downloading_headers.remove(&n);
+		}
+		self.headers.remove_tail(&start);
+		self.bodies.remove_tail(&start);
 	}
 
 	fn request_headers_by_hash(&mut self, sync: &mut SyncIo, peer_id: &PeerId, h: &H256, count: usize, skip: usize, reverse: bool) {
@@ -411,7 +659,7 @@ impl ChainSync {
 			Err(e) => {
 				warn!(target:"sync", "Error sending request: {:?}", e);
 				sync.disable_peer(peer_id);
-				self.on_peer_aborting(peer_id);
+				self.on_peer_aborting(sync, peer_id);
 			}
 			Ok(_) => {
 				let mut peer = self.peers.get_mut(&peer_id).unwrap();
@@ -419,6 +667,147 @@ impl ChainSync {
 			}
 		}
 	}
+
+	fn on_peer_transactions(&mut self, io: &mut SyncIo, peer_id: &PeerId, r: &Rlp) {
+	}
+
+	fn send_status(&mut self, io: &mut SyncIo, peer_id: &PeerId) {
+		let mut packet = RlpStream::new_list(5);
+		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());
+	}
+
+	fn return_block_headers(&self, io: &mut SyncIo, peer_id: &PeerId, r: &Rlp) {
+		// Packet layout:
+		// [ block: { P , B_32 }, maxHeaders: P, skip: P, reverse: P in { 0 , 1 } ]
+		let max_headers: usize = r.val_at(1);
+		let skip: usize = r.val_at(2);
+		let reverse: bool = r.val_at(3);
+		let mut packet = RlpStream::new();
+		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) {
+				Some(hdr) => From::from(rlp::decode::<BlockHeader>(&hdr).number),
+				None => last
+			}
+		}
+		else {
+			r.val_at(0)
+		};
+
+		number = max(1, number);
+		number = min(last, number);
+		let max_count = min(MAX_HEADERS_TO_SEND, max_headers);
+		let mut count = 0;
+		let mut data = Bytes::new();
+		while number < last && number > 1 && count < max_count {
+			match io.chain.block_header_at(number) {
+				Some(mut hdr) => {
+					data.append(&mut hdr);
+					count += 1;
+				}
+				None => {}
+			}
+			number += (if reverse { -(skip + 1) } else { skip + 1 }) as BlockNumber;
+		}
+		let mut rlp = RlpStream::new_list(count as usize);
+		rlp.append_raw(&data, count as usize);
+		io.network.respond(BLOCK_HEADERS_PACKET, rlp.out());
+	}
+
+	fn return_block_bodies(&self, io: &mut SyncIo, peer_id: &PeerId, r: &Rlp) {
+		let mut count = r.item_count();
+		if count == 0 {
+			debug!(target: "sync", "Empty GetBlockBodies request, ignoring.");
+			return;
+		}
+		count = min(count, MAX_BODIES_TO_SEND);
+		let mut added = 0usize;
+		let mut data = Bytes::new();
+		for i in 0..count {
+			match io.chain.block_body(&r.val_at::<H256>(i)) {
+				Some(mut hdr) => {
+					data.append(&mut hdr);
+					added += 1;
+				}
+				None => {}
+			}
+		}
+		let mut rlp = RlpStream::new_list(added);
+		rlp.append_raw(&data, added);
+		io.network.respond(BLOCK_BODIES_PACKET, rlp.out());
+	}
+
+	fn return_node_data(&self, io: &mut SyncIo, peer_id: &PeerId, r: &Rlp) {
+		let mut count = r.item_count();
+		if count == 0 {
+			debug!(target: "sync", "Empty GetNodeData request, ignoring.");
+			return;
+		}
+		count = min(count, MAX_NODE_DATA_TO_SEND);
+		let mut added = 0usize;
+		let mut data = Bytes::new();
+		for i in 0..count {
+			match io.chain.state_data(&r.val_at::<H256>(i)) {
+				Some(mut hdr) => {
+					data.append(&mut hdr);
+					added += 1;
+				}
+				None => {}
+			}
+		}
+		let mut rlp = RlpStream::new_list(added);
+		rlp.append_raw(&data, added);
+		io.network.respond(NODE_DATA_PACKET, rlp.out());
+	}
+
+	fn return_receipts(&self, io: &mut SyncIo, peer_id: &PeerId, r: &Rlp) {
+		let mut count = r.item_count();
+		if count == 0 {
+			debug!(target: "sync", "Empty GetReceipts request, ignoring.");
+			return;
+		}
+		count = min(count, MAX_RECEIPTS_TO_SEND);
+		let mut added = 0usize;
+		let mut data = Bytes::new();
+		for i in 0..count {
+			match io.chain.block_receipts(&r.val_at::<H256>(i)) {
+				Some(mut hdr) => {
+					data.append(&mut hdr);
+					added += 1;
+				}
+				None => {}
+			}
+		}
+		let mut rlp = RlpStream::new_list(added);
+		rlp.append_raw(&data, added);
+		io.network.respond(RECEIPTS_PACKET, rlp.out());
+	}
+
+	pub fn on_packet(&mut self, io: &mut SyncIo, peer: &PeerId, packet_id: u8, data: &[u8]) {
+		let rlp = Rlp::new(data);
+		match packet_id {
+			STATUS_PACKET => self.on_peer_status(io, peer, &rlp),
+			TRANSACTIONS_PACKET => self.on_peer_transactions(io, peer, &rlp),
+			GET_BLOCK_HEADERS_PACKET => self.return_block_headers(io, peer, &rlp),
+			BLOCK_HEADERS_PACKET => self.on_peer_block_headers(io, peer, &rlp),
+			GET_BLOCK_BODIES_PACKET => self.return_block_bodies(io, peer, &rlp),
+			BLOCK_BODIES_PACKET => self.on_peer_block_bodies(io, peer, &rlp),
+			NEW_BLOCK_PACKET => self.on_peer_new_block(io, peer, &rlp),
+			NEW_BLOCK_HASHES_PACKET => self.on_peer_new_hashes(io, peer, &rlp),
+			GET_NODE_DATA_PACKET => self.return_node_data(io, peer, &rlp),
+			GET_RECEIPTS_PACKET => self.return_receipts(io, peer, &rlp),
+			_ => debug!(target: "sync", "Unkown packet {}", packet_id)
+		}
+	}
 }
 
 pub trait ToUsize {
@@ -426,7 +815,7 @@ pub trait ToUsize {
 }
 
 pub trait FromUsize {
-	fn from(s: usize) -> Self;
+	fn from_usize(s: usize) -> Self;
 }
 
 impl ToUsize for BlockNumber {
@@ -436,7 +825,7 @@ impl ToUsize for BlockNumber {
 }
 
 impl FromUsize for BlockNumber {
-	fn from(s: usize) -> BlockNumber {
+	fn from_usize(s: usize) -> BlockNumber {
 		s as BlockNumber
 	}
 }
@@ -444,6 +833,7 @@ impl FromUsize for BlockNumber {
 pub trait RangeCollection<K, V> {
 	fn have_item(&self, key: &K) -> bool;
 	fn find_item(&self, key: &K) -> Option<&V>;
+	fn get_tail(&mut self, key: &K) -> Range<K>;
 	fn remove_head(&mut self, start: &K);
 	fn remove_tail(&mut self, start: &K);
 	fn insert_item(&mut self, key: K, value: V);
@@ -454,7 +844,7 @@ impl<K, V> RangeCollection<K, V> for Vec<(K, Vec<V>)> where K: Ord + PartialEq +
 		match self.binary_search_by(|&(k, _)| k.cmp(key).reverse()) {
 			Ok(_) => true,
 			Err(index) => match self.get(index + 1) {
-				Some(&(ref k, ref v)) => k <= key && (*k + FromUsize::from(v.len())) > *key,
+				Some(&(ref k, ref v)) => k <= key && (*k + FromUsize::from_usize(v.len())) > *key,
 				_ => false
 			},
 		}
@@ -464,12 +854,28 @@ impl<K, V> RangeCollection<K, V> for Vec<(K, Vec<V>)> where K: Ord + PartialEq +
 		match self.binary_search_by(|&(k, _)| k.cmp(key).reverse()) {
 			Ok(index) => self.get(index).unwrap().1.get(0),
 			Err(index) => match self.get(index + 1) {
-				Some(&(ref k, ref v)) if k <= key && (*k + FromUsize::from(v.len())) > *key => v.get((*key - *k).to_usize()),
+				Some(&(ref k, ref v)) if k <= key && (*k + FromUsize::from_usize(v.len())) > *key => v.get((*key - *k).to_usize()),
 				_ => None
 			},
 		}
 	}
 
+	/// Get a range of elements from start till the end of the range
+	fn get_tail(&mut self, key: &K) -> Range<K> {
+		let kv = *key;
+		match self.binary_search_by(|&(k, _)| k.cmp(key).reverse()) {
+			Ok(index) => kv..(kv + FromUsize::from_usize(self[index].1.len())),
+			Err(index) => {
+				let mut empty = false;
+				match self.get_mut(index + 1) {
+					Some(&mut (ref k, ref mut v)) if k <= key && (*k + FromUsize::from_usize(v.len())) > *key => {
+						kv..(*k + FromUsize::from_usize(v.len()))
+					}
+					_ => kv..kv
+				}
+			},
+		}
+	}
 	/// Remove element key and following elements in the same range
 	fn remove_tail(&mut self, key: &K) {
 		match self.binary_search_by(|&(k, _)| k.cmp(key).reverse()) {
@@ -477,7 +883,7 @@ impl<K, V> RangeCollection<K, V> for Vec<(K, Vec<V>)> where K: Ord + PartialEq +
 			Err(index) =>{
 				let mut empty = false;
 				match self.get_mut(index + 1) {
-					Some(&mut (ref k, ref mut v)) if k <= key && (*k + FromUsize::from(v.len())) > *key => {
+					Some(&mut (ref k, ref mut v)) if k <= key && (*k + FromUsize::from_usize(v.len())) > *key => {
 						v.truncate((*key - *k).to_usize());
 						empty = v.is_empty();
 					}
@@ -492,21 +898,21 @@ impl<K, V> RangeCollection<K, V> for Vec<(K, Vec<V>)> where K: Ord + PartialEq +
 
 	/// Remove range elements up to key
 	fn remove_head(&mut self, key: &K) {
-		if *key == FromUsize::from(0) {
+		if *key == FromUsize::from_usize(0) {
 			return
 		}
 
-		let prev = *key - FromUsize::from(1);
+		let prev = *key - FromUsize::from_usize(1);
 		match self.binary_search_by(|&(k, _)| k.cmp(&prev).reverse()) {
 			Ok(index) => { self.remove(index); },
 			Err(index) => {
 				let mut empty = false;
 				match self.get_mut(index + 1) {
-					Some(&mut (ref mut k, ref mut v)) if *k <= prev && (*k + FromUsize::from(v.len())) > *key => {
+					Some(&mut (ref mut k, ref mut v)) if *k <= prev && (*k + FromUsize::from_usize(v.len())) > *key => {
 						let head = v.split_off((*key - *k).to_usize());
 						empty = head.is_empty();
 						let removed = ::std::mem::replace(v, head);
-						let new_k = *k - FromUsize::from(removed.len());
+						let new_k = *k - FromUsize::from_usize(removed.len());
 						::std::mem::replace(k, new_k);
 					}
 					_ => {}
@@ -529,7 +935,7 @@ impl<K, V> RangeCollection<K, V> for Vec<(K, Vec<V>)> where K: Ord + PartialEq +
 		lower += 1;
 
 		let mut to_remove: Option<usize> = None;
-		if lower < self.len() && self[lower].0 + FromUsize::from(self[lower].1.len()) == key {
+		if lower < self.len() && self[lower].0 + FromUsize::from_usize(self[lower].1.len()) == key {
 				// extend into existing chunk
 				self[lower].1.push(value);
 		}
@@ -545,7 +951,7 @@ impl<K, V> RangeCollection<K, V> for Vec<(K, Vec<V>)> where K: Ord + PartialEq +
 				let (mut next, mut inserted) = self.split_at_mut(lower);
 				let mut next = next.last_mut().unwrap();
 				let mut inserted = inserted.first_mut().unwrap();
-				if next.0 == key + FromUsize::from(1)
+				if next.0 == key + FromUsize::from_usize(1)
 				{
 					inserted.1.append(&mut next.1);
 					to_remove = Some(lower - 1);

src/sync/mod.rs

@@ -1,6 +1,7 @@
 use std::sync::{Arc};
 use eth::{BlockChainClient};
-use util::network::{Error as NetworkError, ProtocolHandler, NetworkService, HandlerIo, TimerToken, PeerId};
+use util::network::{ProtocolHandler, NetworkService, HandlerIo, TimerToken, PeerId};
+use sync::chain::{ChainSync, SyncIo};
 
 mod chain;
 
@@ -11,7 +12,8 @@ pub fn new(service: &mut NetworkService, eth_cleint: Arc<BlockChainClient>) {
 
 struct EthSync {
 	idle: bool,
-	chain: Arc<BlockChainClient+Send>
+	chain: Arc<BlockChainClient+Send+Sized>,
+	sync: ChainSync
 }
 
 impl ProtocolHandler for EthSync {
@@ -20,12 +22,15 @@ impl ProtocolHandler for EthSync {
 	}
 
 	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);
 	}
 
 	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);
 	}
 
 	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);
 	}
 
 	fn timeout(&mut self, io: &mut HandlerIo, timer: TimerToken) {