started sync

Cargo.toml

@@ -9,7 +9,7 @@ authors = ["Ethcore <admin@ethcore.io>"]
 [dependencies]
 log = "0.3"
 env_logger = "0.3"
-ethcore-util = "0.1.0"
+ethcore-util = { path = "../ethcore-util" }
 evmjit = { path = "rust-evmjit", optional = true }
 rustc-serialize = "0.3"
 

src/bin/client.rs

@@ -0,0 +1,17 @@
+extern crate ethcore_util as util;
+
+use std::io::*;
+use util::network::{NetworkService};
+
+
+fn main() {
+	let mut service = NetworkService::start().unwrap();
+	loop {
+		let mut cmd = String::new();
+		stdin().read_line(&mut cmd).unwrap();
+		if cmd == "quit" || cmd == "exit" || cmd == "q" {
+			break;
+		}
+	}
+}
+

src/eth.rs

@@ -0,0 +1,46 @@
+use util::hash::H256;
+use util::bytes::Bytes;
+use util::uint::U256;
+
+pub enum QueueStatus {
+	/// Part of the known chain
+	Known,
+	/// Part of the unknown chain
+	Unknown,
+}
+
+pub enum BlockStatus {
+	InChain,
+	Queued(QueueStatus),
+	Bad,
+}
+
+pub struct BlockChainInfo {
+	pub total_difficulty: U256,
+	pub pending_total_difficulty: U256,
+	pub genesis_hash: H256,
+	pub last_block_hash: H256,
+	pub last_block_number: BlockNumber
+}
+
+pub struct BlockQueueStats;
+pub struct TreeRoute;
+
+pub type BlockNumber = u32;
+pub type BlockHeader = ::blockheader::Header;
+
+pub trait BlockChainClient : Sync {
+	fn block_header(&self, h: &H256) -> Option<BlockHeader>;
+	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_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 tree_route(&self, from: &H256, to: &H256) -> TreeRoute;
+	fn import_block(&mut self, b: Bytes) -> BlockStatus;
+	fn queue_stats(&self) -> BlockQueueStats;
+	fn clear_queue(&mut self) -> BlockQueueStats;
+	fn info(&self) -> BlockChainInfo;
+}

src/lib.rs

@@ -1,5 +1,5 @@
 //! Ethcore's ethereum implementation
-//! 
+//!
 //! ### Rust version
 //! - beta
 //! - nightly
@@ -7,44 +7,44 @@
 //! ### Supported platforms:
 //! - OSX
 //! - Linux/Ubuntu
-//! 
+//!
 //! ### Dependencies:
 //! - RocksDB 3.13
 //! - LLVM 3.7 (optional, required for `jit`)
 //! - evmjit (optional, required for `jit`)
 //!
 //! ### Dependencies Installation
-//! 
+//!
 //! - OSX
-//! 
+//!
 //!   - rocksdb
 //!   ```bash
 //!   brew install rocksdb
 //!   ```
-//!   
+//!
 //!   - llvm
-//!     
+//!
 //!       - download llvm 3.7 from http://llvm.org/apt/
 //!
 //!       ```bash
 //!       cd llvm-3.7.0.src
 //!       mkdir build && cd $_
-//!       cmake -G "Unix Makefiles" .. -DCMAKE_C_FLAGS_RELEASE= -DCMAKE_CXX_FLAGS_RELEASE= -DCMAKE_INSTALL_PREFIX=/usr/local/Cellar/llvm/3.7 -DCMAKE_BUILD_TYPE=Release 
+//!       cmake -G "Unix Makefiles" .. -DCMAKE_C_FLAGS_RELEASE= -DCMAKE_CXX_FLAGS_RELEASE= -DCMAKE_INSTALL_PREFIX=/usr/local/Cellar/llvm/3.7 -DCMAKE_BUILD_TYPE=Release
 //!       make && make install
 //!       ```
 //!   - evmjit
-//!   
+//!
 //!       - download from https://github.com/debris/evmjit
-//!       
+//!
 //!       ```bash
 //!       cd evmjit
 //!       mkdir build && cd $_
 //!       cmake -DLLVM_DIR=/usr/local/lib/llvm-3.7/share/llvm/cmake ..
 //!       make && make install
 //!       ```
-//! 
+//!
 //! - Linux/Ubuntu
-//! 
+//!
 //!   - rocksdb
 //!
 //!     ```bash
@@ -52,15 +52,15 @@
 //!     tar xvf rocksdb-3.13.tar.gz && cd rocksdb-rocksdb-3.13 && make shared_lib
 //!     sudo make install
 //!     ```
-//!   
+//!
 //!   - llvm
-//!   
+//!
 //!       - install using packages from http://llvm.org/apt/
-//!   
+//!
 //!   - evmjit
-//!   
+//!
 //!       - download from https://github.com/debris/evmjit
-//!       
+//!
 //!       ```bash
 //!       cd evmjit
 //!       mkdir build && cd $_
@@ -88,6 +88,9 @@ pub mod blockheader;
 pub mod transaction;
 pub mod networkparams;
 pub mod denominations;
+pub mod eth;
+
+pub mod sync;
 
 #[test]
 fn it_works() {

src/sync/chain.rs

@@ -0,0 +1,560 @@
+use std::collections::{HashSet, HashMap};
+use std::cmp::{min, max};
+use std::ops::{Add, Sub};
+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::rlptraits::{Stream, View};
+use eth::{BlockNumber, BlockChainClient};
+
+pub struct SyncIo<'s, 'h> where 'h:'s {
+	network: &'s mut HandlerIo<'h>,
+	chain: &'s mut BlockChainClient
+}
+
+impl<'s, 'h> SyncIo<'s, 'h> {
+	fn disable_peer(&mut self, peer_id: &PeerId) {
+		self.network.disable_peer(*peer_id);
+	}
+}
+
+const STATUS_PACKET: u8 = 0x00;
+const NEW_BLOCK_HASHES_PACKET: u8 = 0x01;
+const TRANSACTIONS_PACKET: u8 = 0x02;
+const GET_BLOCK_HEADERS_PACKET: u8 = 0x03;
+const BLOCK_HEADERS_PACKET: u8 = 0x04;
+const GET_BLOCK_BODIES_PACKET: u8 = 0x05;
+const BLOCK_BODIES_PACKET: u8 = 0x06;
+const NEW_BLOCK_PACKET: u8 = 0x07;
+
+const GET_NODE_DATA_PACKET: u8 = 0x0d;
+const NODE_DATA_PACKET: u8 = 0x0e;
+const GET_RECEIPTS_PACKET: u8 = 0x0f;
+const RECEIPTS_PACKET: u8 = 0x10;
+
+struct Header {
+	///Header data
+	data: Bytes,
+	/// Block hash
+	hash: H256,
+	/// Parent hash
+	parent: H256,
+}
+
+/// Used to identify header by transactions and uncles hashes
+#[derive(Eq, PartialEq, Hash)]
+struct HeaderId {
+	transactions_root: H256,
+	uncles: H256
+}
+
+#[derive(Copy, Clone, Eq, PartialEq, Debug)]
+pub enum SyncState {
+	/// Initial chain sync has not started yet
+	NotSynced,
+	/// Initial chain sync complete. Waiting for new packets
+	Idle,
+	/// Block downloading paused. Waiting for block queue to process blocks and free space
+	Waiting,
+	/// Downloading blocks
+	Blocks,
+	/// Downloading blocks learned from NewHashes packet
+	NewBlocks,
+}
+
+pub struct SyncStatus {
+	state: SyncState,
+	protocol_version: u8,
+	start_block_number: BlockNumber,
+	current_block_number: BlockNumber,
+	highest_block_number: BlockNumber,
+	blocks_total: usize,
+	blocks_received: usize
+}
+
+#[derive(PartialEq, Eq, Debug)]
+enum PeerAsking
+{
+	Nothing,
+	State,
+	BlockHeaders,
+	BlockBodies,
+}
+
+struct PeerInfo {
+	protocol_version: u32,
+	genesis: H256,
+	network_id: U256,
+	latest: H256,
+	difficulty: U256,
+	asking: PeerAsking,
+	asking_blocks: Vec<BlockNumber>
+}
+
+type Body = Bytes;
+
+pub struct ChainSync {
+	/// Sync state
+	state: SyncState,
+	/// Last block number for the start of sync
+	starting_block: BlockNumber,
+	/// Highest block number seen
+	highest_block: BlockNumber,
+	/// Set of block header numbers being downloaded
+	downloading_headers: HashSet<BlockNumber>,
+	/// Set of block body numbers being downloaded
+	downloading_bodies: HashSet<BlockNumber>,
+	/// Downloaded headers.
+	headers: Vec<(BlockNumber, Vec<Header>)>, //TODO: use BTreeMap once range API is sable. For now it a vector sorted in descending order
+	/// Downloaded bodies
+	bodies: Vec<(BlockNumber, Vec<Body>)>, //TODO: use BTreeMap once range API is sable. For now it a vector sorted in descending order
+	/// Peer info
+	peers: HashMap<PeerId, PeerInfo>,
+	/// Used to map body to header
+	header_ids: HashMap<HeaderId, BlockNumber>,
+	/// Last impoted block number
+	last_imported_block: BlockNumber,
+	/// Syncing total  difficulty
+	syncing_difficulty: U256,
+	/// True if common block for our and remote chain has been found
+	have_common_block: bool,
+}
+
+
+impl ChainSync {
+
+	pub fn new(io: &mut SyncIo) -> ChainSync {
+		let mut sync = ChainSync {
+			state: SyncState::NotSynced,
+			starting_block: 0,
+			highest_block: 0,
+			downloading_headers: HashSet::new(),
+			downloading_bodies: HashSet::new(),
+			headers: Vec::new(),
+			bodies: Vec::new(),
+			peers: HashMap::new(),
+			header_ids: HashMap::new(),
+			last_imported_block: 0,
+			syncing_difficulty: U256::from(0u64),
+			have_common_block: false
+		};
+		sync.restart(io);
+		sync
+	}
+
+	/// @returns Synchonization status
+	pub fn status(&self) -> SyncStatus {
+		SyncStatus {
+			state: self.state.clone(),
+			protocol_version: 63,
+			start_block_number: self.starting_block,
+			current_block_number: 0, //TODO:
+			highest_block_number: self.highest_block,
+			blocks_total: (self.last_imported_block - self.starting_block) as usize,
+			blocks_received: (self.highest_block - self.starting_block) as usize
+		}
+	}
+
+	/// Abort all sync activity
+	pub fn abort(&mut self, io: &mut SyncIo) {
+		self.restart(io);
+		self.peers.clear();
+	}
+
+	/// @returns true is Sync is in progress
+	pub fn is_syncing(&self) {
+		self.state != SyncState::Idle;
+	}
+
+	fn reset(&mut self) {
+		self.downloading_headers.clear();
+		self.downloading_bodies.clear();
+		self.headers.clear();
+		self.bodies.clear();
+		for (_, ref mut p) in self.peers.iter_mut() {
+			p.asking_blocks.clear();
+		}
+		self.header_ids.clear();
+		self.syncing_difficulty = From::from(0u64);
+		self.state = SyncState::Idle;
+	}
+
+	/// Restart sync
+	pub fn restart(&mut self, io: &mut SyncIo) {
+		self.reset();
+		self.last_imported_block = 0;
+		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;
+		self.state = SyncState::NotSynced;
+	}
+
+	/// Called by peer to report status
+	pub 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),
+			difficulty: r.val_at(2),
+			latest: r.val_at(3),
+			genesis: r.val_at(4),
+			asking: PeerAsking::Nothing,
+			asking_blocks: Vec::new(),
+		};
+		let old = self.peers.insert(peer_id.clone(), peer);
+		if old.is_some() {
+			panic!("ChainSync: new peer already exists");
+		}
+		self.sync_peer(io, peer_id, false);
+	}
+
+	/// 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) {
+		let item_count = r.item_count();
+		trace!(target: "sync", "BlockHeaders ({} 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 headers");
+			return;
+		}
+		if self.state  == SyncState::Waiting {
+			trace!(target: "sync", "Ignored block headers while waiting");
+			return;
+		}
+	}
+
+	/// Called by peer once it has new block bodies
+	pub fn on_peer_block_bodies(&mut self, io: &mut SyncIo, peer: &PeerId, r: &Rlp) {
+	}
+
+	/// Called by peer once it has new block bodies
+	pub fn on_peer_new_block(&mut self, io: &mut SyncIo, peer: &PeerId, r: &Rlp) {
+	}
+
+	pub fn on_peer_new_hashes(&mut self, io: &mut SyncIo, peer: &PeerId, r: &Rlp) {
+	}
+
+	/// Called by peer when it is disconnecting
+	pub fn on_peer_aborting(&mut self, peer: &PeerId) {
+	}
+
+	/// Resume downloading after witing state
+	fn continue_sync(&mut self) {
+	}
+
+	/// Called after all blocks have been donloaded
+	fn complete_sync(&mut self) {
+	}
+
+	/// Enter waiting state
+	fn pause_sync(&mut self) {
+	}
+
+	fn reset_sync(&mut self)  {
+	}
+
+	fn sync_peer(&mut self, io: &mut SyncIo,  peer_id: &PeerId, force: bool) {
+		let (peer_latest, peer_difficulty) = {
+			let peer = self.peers.get_mut(&peer_id).expect("ChainSync: unknown peer");
+			if peer.asking != PeerAsking::Nothing
+			{
+				debug!(target: "sync", "Can't sync with this peer - outstanding asks.");
+				return;
+			}
+			if self.state == SyncState::Waiting
+			{
+				debug!(target: "sync", "Waiting for block queue");
+				return;
+			}
+			(peer.latest.clone(), peer.difficulty.clone())
+		};
+
+		let td = io.chain.info().pending_total_difficulty;
+		let syncing_difficulty = max(self.syncing_difficulty, td);
+		if force || peer_difficulty > syncing_difficulty {
+			// start sync
+			self.syncing_difficulty = peer_difficulty;
+			if self.state == SyncState::Idle || self.state == SyncState::NotSynced {
+				self.state = SyncState::Blocks;
+			}
+			self.request_headers_by_hash(io, peer_id, &peer_latest, 1, 0, false);
+		}
+		else if self.state == SyncState::Blocks {
+			self.request_blocks(io, peer_id);
+		}
+	}
+
+	fn request_blocks(&mut self, io: &mut SyncIo, peer_id: &PeerId) {
+		self.clear_peer_download(peer_id);
+		// check to see if we need to download any block bodies first
+		let mut needed_bodies: Vec<H256> = Vec::new();
+		let mut needed_numbers: Vec<BlockNumber> = Vec::new();
+		let mut index = 0usize;
+
+		if self.have_common_block && !self.headers.is_empty() && self.headers.last().unwrap().0 == self.last_imported_block + 1 {
+			let mut header = self.headers.len() - 1;
+			while header != 0 && needed_bodies.len() < 1024 && index < self.headers[header].1.len() {
+				let block = self.headers[header].0 + index as BlockNumber;
+				if !self.downloading_bodies.contains(&block) && !self.bodies.have_item(&block) {
+					needed_bodies.push(self.headers[header].1[index].hash.clone());
+					needed_numbers.push(block);
+					self.downloading_bodies.insert(block);
+				}
+				index += 1;
+				if index >= self.headers[header].1.len() {
+					index = 0;
+					header -= 1;
+				}
+			}
+		}
+		if !needed_bodies.is_empty() {
+			replace(&mut self.peers.get_mut(peer_id).unwrap().asking_blocks, needed_numbers);
+			self.request_bodies(io, peer_id, needed_bodies);
+		}
+		else {
+			// check if need to download headers
+			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;
+				if !self.headers.is_empty() {
+					start = min(start, self.headers.last().unwrap().0 as usize - 1);
+				}
+				if start <= 1 {
+					self.have_common_block = true; //reached genesis
+				}
+			}
+			if self.have_common_block {
+				start = self.last_imported_block as usize + 1;
+				let mut next = self.headers.len() - 1;
+				let mut count = 0usize;
+				if !self.headers.is_empty() && start >= self.headers.last().unwrap().0 as usize {
+					start = self.headers.last().unwrap().0 as usize + self.headers.last().unwrap().1.len();
+					next -=1;
+				}
+				while count == 0 && next != 0 {
+					count = min(1024, self.headers[next].0 as usize - start);
+					while count > 0 && self.downloading_headers.contains(&(start as BlockNumber)) {
+						start +=1;
+						count -=1;
+					}
+				}
+				let mut headers: Vec<BlockNumber> = Vec::new();
+				for block in start..(start + count) {
+					if !self.downloading_headers.contains(&(block as BlockNumber)) {
+						headers.push(block as BlockNumber);
+						self.downloading_headers.insert(block as BlockNumber);
+					}
+				}
+				count = self.headers.len();
+				if count > 0 {
+					replace(&mut self.peers.get_mut(peer_id).unwrap().asking_blocks, headers);
+					assert!(!self.headers.have_item(&(start as BlockNumber)));
+					self.request_headers_by_number(io, peer_id, start as BlockNumber, count, 0, false);
+				}
+				else if start >= (self.headers[next].0 as usize) {
+					start = self.headers[next].0 as usize + self.headers[next].1.len();
+					next -=1;
+				}
+			}
+			else {
+				self.request_headers_by_number(io, peer_id, start as BlockNumber, 1, 0, false);
+			}
+		}
+	}
+
+	fn clear_peer_download(&mut self, peer: &PeerId) {
+	}
+	fn clear_all_download(&mut self) {
+	}
+	fn collect_blocks(&mut self) {
+	}
+
+	fn request_headers_by_hash(&mut self, sync: &mut SyncIo, peer_id: &PeerId, h: &H256, count: usize, skip: usize, reverse: bool) {
+		let mut rlp = RlpStream::new_list(4);
+		rlp.append(h);
+		rlp.append(&count);
+		rlp.append(&skip);
+		rlp.append(&if reverse {1u32} else {0u32});
+		self.send_request(sync, peer_id, PeerAsking::BlockHeaders, GET_BLOCK_HEADERS_PACKET, rlp.out());
+	}
+
+	fn request_headers_by_number(&mut self, sync: &mut SyncIo, peer_id: &PeerId, n: BlockNumber, count: usize, skip: usize, reverse: bool) {
+		let mut rlp = RlpStream::new_list(4);
+		rlp.append(&n);
+		rlp.append(&count);
+		rlp.append(&skip);
+		rlp.append(&if reverse {1u32} else {0u32});
+		self.send_request(sync, peer_id, PeerAsking::BlockHeaders, GET_BLOCK_HEADERS_PACKET, rlp.out());
+	}
+
+	fn request_bodies(&mut self, sync: &mut SyncIo, peer_id: &PeerId, hashes: Vec<H256>) {
+		let mut rlp = RlpStream::new_list(hashes.len());
+		for h in hashes {
+			rlp.append(&h);
+		}
+		self.send_request(sync, peer_id, PeerAsking::BlockHeaders, GET_BLOCK_BODIES_PACKET, rlp.out());
+	}
+
+	fn send_request(&mut self, sync: &mut SyncIo, peer_id: &PeerId, asking: PeerAsking,  packet_id: PacketId, packet: Bytes) {
+		{
+			let mut peer = self.peers.get_mut(&peer_id).expect("ChainSync: unknown peer");
+			if peer.asking != PeerAsking::Nothing {
+				warn!(target:"sync", "Asking {:?} while requesting {:?}", asking, peer.asking);
+			}
+		}
+		match sync.network.send(*peer_id, packet_id, packet) {
+			Err(e) => {
+				warn!(target:"sync", "Error sending request: {:?}", e);
+				sync.disable_peer(peer_id);
+				self.on_peer_aborting(peer_id);
+			}
+			Ok(_) => {
+				let mut peer = self.peers.get_mut(&peer_id).unwrap();
+				peer.asking = asking;
+			}
+		}
+	}
+}
+
+pub trait ToUsize {
+	fn to_usize(&self) -> usize;
+}
+
+pub trait FromUsize {
+	fn from(s: usize) -> Self;
+}
+
+impl ToUsize for BlockNumber {
+	fn to_usize(&self) -> usize {
+		*self as usize
+	}
+}
+
+impl FromUsize for BlockNumber {
+	fn from(s: usize) -> BlockNumber {
+		s as BlockNumber
+	}
+}
+
+pub trait RangeCollection<K, V> {
+	fn have_item(&self, key: &K) -> bool;
+	fn find_item(&self, key: &K) -> Option<&V>;
+	fn remove_head(&mut self, start: &K);
+	fn remove_tail(&mut self, start: &K);
+	fn insert_item(&mut self, key: K, value: V);
+}
+
+impl<K, V> RangeCollection<K, V> for Vec<(K, Vec<V>)> where K: Ord + PartialEq + Add<Output = K> + Sub<Output = K> + Copy + FromUsize + ToUsize {
+	fn have_item(&self, key: &K) -> bool {
+		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,
+				_ => false
+			},
+		}
+	}
+
+	fn find_item(&self, key: &K) -> Option<&V> {
+		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()),
+				_ => None
+			},
+		}
+	}
+
+	/// 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()) {
+			Ok(index) => { self.remove(index); },
+			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 => {
+						v.truncate((*key - *k).to_usize());
+						empty = v.is_empty();
+					}
+					_ => {}
+				}
+				if empty {
+					self.remove(index + 1);
+				}
+			},
+		}
+	}
+
+	/// Remove range elements up to key
+	fn remove_head(&mut self, key: &K) {
+		if *key == FromUsize::from(0) {
+			return
+		}
+
+		let prev = *key - FromUsize::from(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 => {
+						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());
+						::std::mem::replace(k, new_k);
+					}
+					_ => {}
+				}
+				if empty {
+					self.remove(index + 1);
+				}
+			},
+		}
+	}
+
+	fn insert_item(&mut self, key: K, value: V) {
+		assert!(!self.have_item(&key));
+
+		let mut lower = match self.binary_search_by(|&(k, _)| k.cmp(&key).reverse()) {
+			Ok(index) => index,
+			Err(index) => index,
+		};
+
+		lower += 1;
+
+		let mut to_remove: Option<usize> = None;
+		if lower < self.len() && self[lower].0 + FromUsize::from(self[lower].1.len()) == key {
+				// extend into existing chunk
+				self[lower].1.push(value);
+		}
+		else {
+			// insert a new chunk
+			let mut range: Vec<V> = vec![value];
+			self.insert(lower, (key, range));
+		};
+		let next = lower - 1;
+		if next < self.len()
+		{
+			{
+				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)
+				{
+					inserted.1.append(&mut next.1);
+					to_remove = Some(lower - 1);
+				}
+			}
+
+			if let Some(r) = to_remove {
+				self.remove(r);
+			}
+		}
+	}
+}

src/sync/mod.rs

@@ -0,0 +1,35 @@
+use std::sync::{Arc};
+use eth::{BlockChainClient};
+use util::network::{Error as NetworkError, ProtocolHandler, NetworkService, HandlerIo, TimerToken, PeerId};
+
+mod chain;
+
+
+pub fn new(service: &mut NetworkService, eth_cleint: Arc<BlockChainClient>) {
+
+}
+
+struct EthSync {
+	idle: bool,
+	chain: Arc<BlockChainClient+Send>
+}
+
+impl ProtocolHandler for EthSync {
+	fn initialize(&mut self, io: &mut HandlerIo) {
+		io.register_timer(1000);
+	}
+
+	fn read(&mut self, io: &mut HandlerIo, peer: &PeerId, packet_id: u8, data: &[u8]) {
+	}
+
+	fn connected(&mut self, io: &mut HandlerIo, peer: &PeerId) {
+	}
+
+	fn disconnected(&mut self, io: &mut HandlerIo, peer: &PeerId) {
+	}
+
+	fn timeout(&mut self, io: &mut HandlerIo, timer: TimerToken) {
+	}
+}
+
+