From 5346539ef83cfa2b3720265c0fcdddae9c6dc761 Mon Sep 17 00:00:00 2001
From: Robert Habermeier <rphmeier@gmail.com>
Date: Thu, 15 Dec 2016 18:45:11 +0100
Subject: [PATCH] minimal header import and client service

---
 ethcore/light/src/client/mod.rs     | 29 +++++++++++-
 ethcore/light/src/client/service.rs | 73 +++++++++++++++++++++++++++++
 sync/src/light_sync/sync_round.rs   |  3 +-
 3 files changed, 102 insertions(+), 3 deletions(-)
 create mode 100644 ethcore/light/src/client/service.rs

diff --git a/ethcore/light/src/client/mod.rs b/ethcore/light/src/client/mod.rs
index 4b8a37366..d51f2c484 100644
--- a/ethcore/light/src/client/mod.rs
+++ b/ethcore/light/src/client/mod.rs
@@ -35,13 +35,18 @@ use request;
 
 use self::header_chain::HeaderChain;
 
+pub use self::service::Service;
+
 pub mod cht;
+
 mod header_chain;
+mod service;
 
 /// Configuration for the light client.
 #[derive(Debug, Default, Clone)]
 pub struct Config {
-	queue: queue::Config,
+	/// Verification queue config.
+	pub queue: queue::Config,
 }
 
 /// Trait for interacting with the header chain abstractly.
@@ -139,6 +144,28 @@ impl Client {
 	pub fn cht_root(&self, i: usize) -> Option<H256> {
 		self.chain.cht_root(i)
 	}
+
+	/// Import a set of pre-verified headers from the queue.
+	pub fn import_verified(&self) {
+		const MAX: usize = 256;
+
+		let mut bad = Vec::new();
+		let mut good = Vec::new();
+		for verified_header in self.queue.drain(MAX) {
+			let hash = verified_header.hash();
+
+			match self.chain.insert(::rlp::encode(&verified_header).to_vec()) {
+				Ok(()) => good.push(hash),
+				Err(e) => {
+					debug!(target: "client", "Error importing header {}: {}", hash, e);
+					bad.push(hash);
+				}
+			}
+		}
+
+		self.queue.mark_as_bad(&bad);
+		self.queue.mark_as_good(&good);
+	}
 }
 
 impl LightChainClient for Client {
diff --git a/ethcore/light/src/client/service.rs b/ethcore/light/src/client/service.rs
new file mode 100644
index 000000000..79c53bac6
--- /dev/null
+++ b/ethcore/light/src/client/service.rs
@@ -0,0 +1,73 @@
+// Copyright 2015, 2016 Parity Technologies (UK) Ltd.
+// This file is part of Parity.
+
+// Parity is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// Parity is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with Parity.  If not, see <http://www.gnu.org/licenses/>.
+
+//! Minimal IO service for light client.
+//! Just handles block import messages and passes them to the client.
+
+use std::sync::Arc;
+
+use ethcore::service::ClientIoMessage;
+use ethcore::spec::Spec;
+use io::{IoContext, IoError, IoHandler, IoService};
+
+use super::{Client, Config as ClientConfig};
+
+/// Light client service.
+pub struct Service {
+	client: Arc<Client>,
+	_io_service: IoService<ClientIoMessage>,
+}
+
+impl Service {
+	/// Start the service: initialize I/O workers and client itself.
+	pub fn start(config: ClientConfig, spec: &Spec) -> Result<Self, IoError> {
+		let io_service = try!(IoService::<ClientIoMessage>::start());
+		let client = Arc::new(Client::new(config, spec, io_service.channel()));
+		try!(io_service.register_handler(Arc::new(ImportBlocks(client.clone()))));
+
+		Ok(Service {
+			client: client,
+			_io_service: io_service,
+		})
+	}
+
+	/// Get a handle to the client.
+	pub fn client(&self) -> &Arc<Client> {
+		&self.client
+	}
+}
+
+struct ImportBlocks(Arc<Client>);
+
+impl IoHandler<ClientIoMessage> for ImportBlocks {
+	fn message(&self, _io: &IoContext<ClientIoMessage>, message: &ClientIoMessage) {
+		if let ClientIoMessage::BlockVerified = *message {
+			self.0.import_verified();
+		}
+	}
+}
+
+#[cfg(test)]
+mod tests {
+	use super::Service;
+	use ethcore::spec::Spec;
+
+	#[test]
+	fn it_works() {
+		let spec = Spec::new_test();
+		Service::start(Default::default(), &spec).unwrap();
+	}
+}
diff --git a/sync/src/light_sync/sync_round.rs b/sync/src/light_sync/sync_round.rs
index 0442cc5ce..5f121d00c 100644
--- a/sync/src/light_sync/sync_round.rs
+++ b/sync/src/light_sync/sync_round.rs
@@ -225,6 +225,7 @@ impl Fetcher {
 					}
 
 					self.complete_requests.insert(subchain_parent, request);
+					self.collect_ready();
 				}
 
 				// state transition not triggered until drain is finished.
@@ -267,8 +268,6 @@ impl Fetcher {
 	}
 
 	fn drain(mut self, headers: &mut Vec<Header>, max: usize) -> SyncRound {
-		self.collect_ready();
-
 		let max = ::std::cmp::min(max, self.ready.len());
 		headers.extend(self.ready.drain(0..max));