From ccdf5d587372f23d2ad9a4d6f05d5b01a8a67c3a Mon Sep 17 00:00:00 2001
From: Robert Habermeier <rphmeier@gmail.com>
Date: Mon, 19 Dec 2016 12:28:42 +0100
Subject: [PATCH] increase tick timer and limit peers to one req

---
 ethcore/light/src/net/error.rs |  8 ++++++--
 ethcore/light/src/net/mod.rs   | 35 +++++++++++++++++++++++++---------
 sync/src/light_sync/mod.rs     |  2 --
 3 files changed, 32 insertions(+), 13 deletions(-)

diff --git a/ethcore/light/src/net/error.rs b/ethcore/light/src/net/error.rs
index 42d038679..6a7746543 100644
--- a/ethcore/light/src/net/error.rs
+++ b/ethcore/light/src/net/error.rs
@@ -62,6 +62,8 @@ pub enum Error {
 	UnsupportedProtocolVersion(u8),
 	/// Bad protocol version.
 	BadProtocolVersion,
+	/// Peer is overburdened.
+	Overburdened,
 }
 
 impl Error {
@@ -79,6 +81,7 @@ impl Error {
 			Error::NotServer => Punishment::Disable,
 			Error::UnsupportedProtocolVersion(_) => Punishment::Disable,
 			Error::BadProtocolVersion => Punishment::Disable,
+			Error::Overburdened => Punishment::None,
 		}
 	}
 }
@@ -107,8 +110,9 @@ impl fmt::Display for Error {
 			Error::UnknownPeer => write!(f, "Unknown peer"),
 			Error::UnsolicitedResponse => write!(f, "Peer provided unsolicited data"),
 			Error::NotServer => write!(f, "Peer not a server."),
-			Error::UnsupportedProtocolVersion(pv) => write!(f, "Unsupported protocol version: {}", pv),	
+			Error::UnsupportedProtocolVersion(pv) => write!(f, "Unsupported protocol version: {}", pv),
 			Error::BadProtocolVersion => write!(f, "Bad protocol version in handshake"),
+			Error::Overburdened => write!(f, "Peer overburdened"),
 		}
 	}
-}
\ No newline at end of file
+}
diff --git a/ethcore/light/src/net/mod.rs b/ethcore/light/src/net/mod.rs
index 464c71fbe..766cd9c4b 100644
--- a/ethcore/light/src/net/mod.rs
+++ b/ethcore/light/src/net/mod.rs
@@ -55,6 +55,9 @@ pub use self::status::{Status, Capabilities, Announcement};
 const TIMEOUT: TimerToken = 0;
 const TIMEOUT_INTERVAL_MS: u64 = 1000;
 
+const TICK_TIMEOUT: TimerToken = 1;
+const TICK_TIMEOUT_INTERVAL_MS: u64 = 5000;
+
 // minimum interval between updates.
 const UPDATE_INTERVAL_MS: i64 = 5000;
 
@@ -132,8 +135,9 @@ struct Peer {
 	status: Status,
 	capabilities: Capabilities,
 	remote_flow: Option<(Buffer, FlowParams)>,
-	sent_head: H256, // last head we've given them.
+	sent_head: H256, // last chain head we've given them.
 	last_update: SteadyTime,
+	idle: bool, // make into a current percentage of max buffer being requested?
 }
 
 impl Peer {
@@ -263,10 +267,16 @@ impl LightProtocol {
 	pub fn max_requests(&self, peer: PeerId, kind: request::Kind) -> usize {
 		self.peers.read().get(&peer).and_then(|peer| {
 			let mut peer = peer.lock();
-			match peer.remote_flow.as_mut() {
-				Some(&mut (ref mut buf, ref flow)) => {
+			let idle = peer.idle;
+			match peer.remote_flow {
+				Some((ref mut buf, ref flow)) => {
 					flow.recharge(buf);
-					Some(flow.max_amount(&*buf, kind))
+
+					if !idle {
+						Some(0)
+					} else {
+						Some(flow.max_amount(&*buf, kind))
+					}
 				}
 				None => None,
 			}
@@ -284,6 +294,8 @@ impl LightProtocol {
 		let peer = try!(peers.get(peer_id).ok_or_else(|| Error::UnknownPeer));
 		let mut peer = peer.lock();
 
+		if !peer.idle { return Err(Error::Overburdened) }
+
 		match peer.remote_flow {
 			Some((ref mut buf, ref flow)) => {
 				flow.recharge(buf);
@@ -309,6 +321,7 @@ impl LightProtocol {
 
 		io.send(*peer_id, packet_id, packet_data);
 
+		peer.idle = false;
 		self.pending_requests.write().insert(req_id, Requested {
 			request: request,
 			timestamp: SteadyTime::now(),
@@ -412,6 +425,8 @@ impl LightProtocol {
 		match peers.get(peer) {
 			Some(peer_info) => {
 				let mut peer_info = peer_info.lock();
+				peer_info.idle = true;
+
 				match peer_info.remote_flow.as_mut() {
 					Some(&mut (ref mut buf, ref mut flow)) => {
 						let actual_buffer = ::std::cmp::min(cur_buffer, *flow.limit());
@@ -620,6 +635,7 @@ impl LightProtocol {
 			remote_flow: remote_flow,
 			sent_head: pending.sent_head,
 			last_update: pending.last_update,
+			idle: true,
 		}));
 
 		for handler in &self.handlers {
@@ -1124,7 +1140,10 @@ fn punish(peer: PeerId, io: &IoContext, e: Error) {
 
 impl NetworkProtocolHandler for LightProtocol {
 	fn initialize(&self, io: &NetworkContext) {
-		io.register_timer(TIMEOUT, TIMEOUT_INTERVAL_MS).expect("Error registering sync timer.");
+		io.register_timer(TIMEOUT, TIMEOUT_INTERVAL_MS)
+			.expect("Error registering sync timer.");
+		io.register_timer(TICK_TIMEOUT, TICK_TIMEOUT_INTERVAL_MS)
+			.expect("Error registering sync timer.");
 	}
 
 	fn read(&self, io: &NetworkContext, peer: &PeerId, packet_id: u8, data: &[u8]) {
@@ -1141,10 +1160,8 @@ impl NetworkProtocolHandler for LightProtocol {
 
 	fn timeout(&self, io: &NetworkContext, timer: TimerToken) {
 		match timer {
-			TIMEOUT =>  {
-				self.timeout_check(io);
-				self.tick_handlers(io);
-			},
+			TIMEOUT => self.timeout_check(io),
+			TICK_TIMEOUT => self.tick_handlers(io),
 			_ => warn!(target: "les", "received timeout on unknown token {}", timer),
 		}
 	}
diff --git a/sync/src/light_sync/mod.rs b/sync/src/light_sync/mod.rs
index 97ddfad46..6f5a53c5f 100644
--- a/sync/src/light_sync/mod.rs
+++ b/sync/src/light_sync/mod.rs
@@ -417,8 +417,6 @@ impl<L: LightChainClient> LightSync<L> {
 				rng.shuffle(&mut peer_ids);
 
 				for peer in &peer_ids {
-					let peer_info = peers.get(peer).expect("key known to be present; qed");
-					let mut peer_info = peer_info.lock();
 					if ctx.max_requests(*peer, request::Kind::Headers) >= req.max {
 						match ctx.request_from(*peer, request::Request::Headers(req.clone())) {
 							Ok(id) => {