Sync optimization (#1385)

* Minor sync fixes

* Fixed session count sub

* handle NewBlock when downloading

* Accept new blocks right away

* block collection update fixed

sync/src/blocks.rs

@@ -295,6 +295,10 @@ impl BlockCollection {
 		let old_subchains: HashSet<_> = { self.heads.iter().cloned().collect() };
 		for s in self.heads.drain(..) {
 			let mut h = s.clone();
+			if !self.blocks.contains_key(&h) {
+				new_heads.push(h);
+				continue;
+			}
 			loop {
 				match self.parents.get(&h) {
 					Some(next) => {
@@ -394,7 +398,7 @@ mod test {
 		assert_eq!(&bc.drain()[..], &blocks[6..16]);
 		assert_eq!(hashes[15], bc.heads[0]);
 
-		bc.insert_headers(headers[16..].to_vec());
+		bc.insert_headers(headers[15..].to_vec());
 		bc.drain();
 		assert!(bc.is_empty());
 	}
@@ -420,5 +424,24 @@ mod test {
 		assert!(bc.head.is_some());
 		assert_eq!(hashes[21], bc.heads[0]);
 	}
+
+	#[test]
+	fn insert_headers_no_gap() {
+		let mut bc = BlockCollection::new();
+		assert!(is_empty(&bc));
+		let client = TestBlockChainClient::new();
+		let nblocks = 200;
+		client.add_blocks(nblocks, EachBlockWith::Nothing);
+		let blocks: Vec<_> = (0 .. nblocks).map(|i| (&client as &BlockChainClient).block(BlockID::Number(i as BlockNumber)).unwrap()).collect();
+		let headers: Vec<_> = blocks.iter().map(|b| Rlp::new(b).at(0).as_raw().to_vec()).collect();
+		let hashes: Vec<_> = headers.iter().map(|h| HeaderView::new(h).sha3()).collect();
+		let heads: Vec<_> = hashes.iter().enumerate().filter_map(|(i, h)| if i % 20 == 0 { Some(h.clone()) } else { None }).collect();
+		bc.reset_to(heads);
+
+		bc.insert_headers(headers[1..2].to_vec());
+		assert!(bc.drain().is_empty());
+		bc.insert_headers(headers[0..1].to_vec());
+		assert_eq!(bc.drain().len(), 2);
+	}
 }
 

sync/src/chain.rs

@@ -100,6 +100,7 @@ use io::SyncIo;
 use time;
 use super::SyncConfig;
 use blocks::BlockCollection;
+use rand::{thread_rng, Rng};
 
 known_heap_size!(0, PeerInfo);
 
@@ -308,7 +309,6 @@ impl ChainSync {
 		}
 		self.syncing_difficulty = From::from(0u64);
 		self.state = SyncState::Idle;
-		self.blocks.clear();
 		self.active_peers = self.peers.keys().cloned().collect();
 	}
 
@@ -393,7 +393,7 @@ impl ChainSync {
 		self.clear_peer_download(peer_id);
 		let expected_hash = self.peers.get(&peer_id).and_then(|p| p.asking_hash);
 		let expected_asking = if self.state == SyncState::ChainHead { PeerAsking::Heads } else { PeerAsking::BlockHeaders };
-		if !self.reset_peer_asking(peer_id, expected_asking) {
+		if !self.reset_peer_asking(peer_id, expected_asking) || expected_hash.is_none() {
 			trace!(target: "sync", "Ignored unexpected headers");
 			self.continue_sync(io);
 			return Ok(());
@@ -533,10 +533,6 @@ impl ChainSync {
 		let header_rlp = try!(block_rlp.at(0));
 		let h = header_rlp.as_raw().sha3();
 		trace!(target: "sync", "{} -> NewBlock ({})", peer_id, h);
-		if self.state != SyncState::Idle {
-			trace!(target: "sync", "NewBlock ignored while seeking");
-			return Ok(());
-		}
 		let header: BlockHeader = try!(header_rlp.as_val());
 		let mut unknown = false;
 		{
@@ -544,7 +540,6 @@ impl ChainSync {
 			peer.latest_hash = header.hash();
 			peer.latest_number = Some(header.number());
 		}
-		if header.number <= self.last_imported_block + 1 {
 		match io.chain().import_block(block_rlp.as_raw().to_vec()) {
 			Err(Error::Import(ImportError::AlreadyInChain)) => {
 				trace!(target: "sync", "New block already in chain {:?}", h);
@@ -568,11 +563,10 @@ impl ChainSync {
 				io.disable_peer(peer_id);
 			}
 		};
-		}
-		else {
-			unknown = true;
-		}
 		if unknown {
+			if self.state != SyncState::Idle {
+				trace!(target: "sync", "NewBlock ignored while seeking");
+			} else {
 				trace!(target: "sync", "New unknown block {:?}", h);
 				//TODO: handle too many unknown blocks
 				let difficulty: U256 = try!(r.val_at(1));
@@ -585,6 +579,7 @@ impl ChainSync {
 				}
 				self.sync_peer(io, peer_id, true);
 			}
+		}
 		Ok(())
 	}
 
@@ -661,7 +656,7 @@ impl ChainSync {
 	/// Resume downloading
 	fn continue_sync(&mut self, io: &mut SyncIo) {
 		let mut peers: Vec<(PeerId, U256)> = self.peers.iter().map(|(k, p)| (*k, p.difficulty.unwrap_or_else(U256::zero))).collect();
-		peers.sort_by(|&(_, d1), &(_, d2)| d1.cmp(&d2).reverse()); //TODO: sort by rating
+		thread_rng().shuffle(&mut peers); //TODO: sort by rating
 		trace!(target: "sync", "Syncing with {}/{} peers", self.active_peers.len(), peers.len());
 		for (p, _) in peers {
 			if self.active_peers.contains(&p) {
@@ -688,6 +683,10 @@ impl ChainSync {
 
 	/// Find something to do for a peer. Called for a new peer or when a peer is done with it's task.
 	fn sync_peer(&mut self, io: &mut SyncIo, peer_id: PeerId, force: bool) {
+		if !self.active_peers.contains(&peer_id) {
+			trace!(target: "sync", "Skipping deactivated peer");
+			return;
+		}
 		let (peer_latest, peer_difficulty) = {
 			let peer = self.peers.get_mut(&peer_id).unwrap();
 			if peer.asking != PeerAsking::Nothing {

util/src/network/host.rs

@@ -191,7 +191,7 @@ pub struct NetworkContext<'s, Message> where Message: Send + Sync + Clone + 'sta
 	sessions: Arc<RwLock<Slab<SharedSession>>>,
 	session: Option<SharedSession>,
 	session_id: Option<StreamToken>,
-	reserved_peers: &'s HashSet<NodeId>,
+	_reserved_peers: &'s HashSet<NodeId>,
 }
 
 impl<'s, Message> NetworkContext<'s, Message> where Message: Send + Sync + Clone + 'static, {
@@ -207,7 +207,7 @@ impl<'s, Message> NetworkContext<'s, Message> where Message: Send + Sync + Clone
 			session_id: id,
 			session: session,
 			sessions: sessions,
-			reserved_peers: reserved_peers,
+			_reserved_peers: reserved_peers,
 		}
 	}
 
@@ -837,9 +837,9 @@ impl<Message> Host<Message> where Message: Send + Sync + Clone {
 				let mut s = session.lock().unwrap();
 				if !s.expired() {
 					if s.is_ready() {
+						self.num_sessions.fetch_sub(1, AtomicOrdering::SeqCst);
 						for (p, _) in self.handlers.read().unwrap().iter() {
 							if s.have_capability(p)  {
-								self.num_sessions.fetch_sub(1, AtomicOrdering::SeqCst);
 								to_disconnect.push(p);
 							}
 						}