light: search for common ancestor with peers

ethcore/light/src/client/header_chain.rs

@@ -276,7 +276,7 @@ mod tests {
 			header.set_timestamp(rolling_timestamp);
 			header.set_difficulty(*genesis_header.difficulty() * i.into());
 
-			chain.insert(::rlp::encode(&header).to_vec());
+			chain.insert(::rlp::encode(&header).to_vec()).unwrap();
 
 			parent_hash = header.hash();
 			rolling_timestamp += 10;

ethcore/light/src/client/mod.rs

@@ -18,6 +18,7 @@
 
 use ethcore::block_import_error::BlockImportError;
 use ethcore::block_status::BlockStatus;
+use ethcore::ids::BlockId;
 use ethcore::verification::queue::{self, HeaderQueue};
 use ethcore::transaction::SignedTransaction;
 use ethcore::blockchain_info::BlockChainInfo;
@@ -33,7 +34,7 @@ use request;
 
 use self::header_chain::HeaderChain;
 
-mod cht;
+pub mod cht;
 mod header_chain;
 
 /// Configuration for the light client.
@@ -84,16 +85,8 @@ impl Client {
 		}
 	}
 
-	/// Get the header queue info.
+	/// Get the chain info.
-	pub fn queue_info(&self) -> queue::QueueInfo {
+	pub fn chain_info(&self) -> BlockChainInfo {
-		self.queue.queue_info()
-	}
-
-}
-
-// dummy implementation -- may draw from canonical cache further on.
-impl Provider for Client {
-	fn chain_info(&self) -> BlockChainInfo {
 		let best_block = self.chain.best_block();
 		let first_block = self.chain.first_block();
 		let genesis_hash = self.chain.genesis_hash();
@@ -111,6 +104,28 @@ impl Provider for Client {
 		}
 	}
 
+	/// Get the header queue info.
+	pub fn queue_info(&self) -> queue::QueueInfo {
+		self.queue.queue_info()
+	}
+
+	/// Get a block header by Id.
+	pub fn get_header(&self, id: BlockId) -> Option<Bytes> {
+		self.chain.get_header(id)
+	}
+
+	/// Get the `i`th CHT root.
+	pub fn cht_root(&self, i: usize) -> Option<H256> {
+		self.chain.cht_root(i)
+	}
+}
+
+// dummy implementation -- may draw from canonical cache further on.
+impl Provider for Client {
+	fn chain_info(&self) -> BlockChainInfo {
+		Client::chain_info(self)
+	}
+
 	fn reorg_depth(&self, _a: &H256, _b: &H256) -> Option<u64> {
 		None
 	}

ethcore/light/src/net/mod.rs

@@ -38,7 +38,7 @@ use request::{self, HashOrNumber, Request};
 
 use self::buffer_flow::{Buffer, FlowParams};
 use self::context::Ctx;
-use self::error::{Error, Punishment};
+use self::error::Punishment;
 
 mod buffer_flow;
 mod context;
@@ -48,6 +48,7 @@ mod status;
 #[cfg(test)]
 mod tests;
 
+pub use self::error::Error;
 pub use self::context::{EventContext, IoContext};
 pub use self::status::{Status, Capabilities, Announcement};
 

sync/src/lib.rs

@@ -54,6 +54,7 @@ extern crate ethcore_ipc as ipc;
 mod chain;
 mod blocks;
 mod block_sync;
+mod light_sync;
 mod sync_io;
 mod snapshot;
 mod transactions_stats;

sync/src/light_sync/mod.rs

@@ -28,12 +28,14 @@ use std::collections::{BinaryHeap, HashMap};
 use std::fmt;
 use std::sync::Arc;
 
-use light::client::{Client, BlockDescriptor};
+use ethcore::header::Header;
-use light::net::{Error as NetError, Handler, EventContext, Capabilities, ReqId};
+
+use light::client::Client;
+use light::net::{Announcement, Error as NetError, Handler, EventContext, Capabilities, ReqId, Status};
 use light::request;
 use network::PeerId;
 use rlp::{UntrustedRlp, View};
-use util::{U256, H256};
+use util::{Bytes, U256, H256, Mutex, RwLock};
 
 // How many headers we request at a time when searching for best
 // common ancestor with peer.
@@ -53,6 +55,12 @@ enum Error {
 	ProtocolLevel(NetError),
 }
 
+impl From<NetError> for Error {
+	fn from(net_error: NetError) -> Self {
+		Error::ProtocolLevel(net_error)
+	}
+}
+
 impl fmt::Display for Error {
 	fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
 		match *self {
@@ -87,13 +95,13 @@ impl UnconfirmedPeer {
 	fn create(ctx: &EventContext, chain_info: ChainInfo, best_num: u64) -> Result<Self, Error> {
 		let this = ctx.peer();
 
-		if ctx.max_requests(this, request::Kind::Headers) < UNCONFIRMED_SEARCH_SIZE {
+		if ctx.max_requests(this, request::Kind::Headers) < UNCONFIRMED_SEARCH_SIZE as usize {
 			return Err(Error::UselessPeer); // a peer which allows this few header reqs isn't useful anyway.
 		}
 
 		let req_id = try!(ctx.request_from(this, request::Request::Headers(request::Headers {
 			start: best_num.into(),
-			max: ::std::cmp::min(best_num, UNCONFIRMED_SEARCH_SIZE),
+			max: ::std::cmp::min(best_num, UNCONFIRMED_SEARCH_SIZE) as usize,
 			skip: 0,
 			reverse: true,
 		})));
@@ -101,7 +109,7 @@ impl UnconfirmedPeer {
 		Ok(UnconfirmedPeer {
 			chain_info: chain_info,
 			last_batched: best_num,
-			req_id: ReqId,
+			req_id: req_id,
 		})
 	}
 
@@ -142,13 +150,15 @@ impl UnconfirmedPeer {
 		// nothing found, nothing prehistoric.
 		// send the next request.
 		let req_id = try!(ctx.request_from(this, request::Request::Headers(request::Headers {
-			start: cur_num,
+			start: cur_num.into(),
-			max: ::std::cmp::min(cur_num, UNCONFIRMED_SEARCH_SIZE),
+			max: ::std::cmp::min(cur_num, UNCONFIRMED_SEARCH_SIZE) as usize,
 			skip: 0,
 			reverse: true,
 		})));
 
 		self.req_id = req_id;
+
+		Ok(None)
 	}
 }
 
@@ -168,13 +178,13 @@ pub struct LightSync {
 	best_seen: Mutex<Option<(H256, U256)>>, // best seen block on the network.
 	peers: RwLock<HashMap<PeerId, Peer>>, // peers which are relevant to synchronization.
 	client: Arc<Client>,
-	downloader: Downloader,
-	assigned_requests: HashMap<ReqId, HeaderRequest>,
 }
 
 impl Handler for LightSync {
 	fn on_connect(&self, ctx: &EventContext, status: &Status, capabilities: &Capabilities) {
-		if !capabilities.serve_headers || status.head_num <= self.client.best_block().number {
+		let our_best = self.client.chain_info().best_block_number;
+
+		if !capabilities.serve_headers || status.head_num <= our_best {
 			trace!(target: "sync", "Ignoring irrelevant peer: {}", ctx.peer());
 			return;
 		}
@@ -184,7 +194,6 @@ impl Handler for LightSync {
 			head_hash: status.head_hash,
 			head_num: status.head_num,
 		};
-		let our_best = self.client.chain_info().best_block_number;
 		let unconfirmed = match UnconfirmedPeer::create(ctx, chain_info, our_best) {
 			Ok(unconfirmed) => unconfirmed,
 			Err(e) => {
@@ -193,7 +202,7 @@ impl Handler for LightSync {
 			}
 		};
 
-		self.peers.write().insert(ctx.peer(), Mutex::new(unconfirmed));
+		self.peers.write().insert(ctx.peer(), Peer::SearchCommon(Mutex::new(unconfirmed)));
 	}
 }
 
@@ -206,7 +215,7 @@ impl LightSync {
 	pub fn new(client: Arc<Client>) -> Self {
 		LightSync {
 			best_seen: Mutex::new(None),
-			peers: HashMap::new(),
+			peers: RwLock::new(HashMap::new()),
 			client: client,
 		}
 	}