Implement PIP messages, request builder, and handlers (#4945)

* return errors on database corruption

* fix tests, json tests

* fix remainder of build

* buffer flow -> request credits

* proving state backend

* generate transaction proofs from provider

* network messages for transaction proof

* transaction proof test

* test for transaction proof message

* fix call bug

* request transaction proofs from on_demand

* most of proved_execution rpc

* proved execution future

* initial request definitions

* RLP encoding and decoding for requests

* proofs of non-existance in ProvingBlockChainClient

* new requests in provider.

* encode and decode responses

* complete initial request changes

* handle request packet in LightProtocol

* handle response packets

* implement requesting from

* re-do cost table

* get tests compiling

* fix cost table RLP encoding

* roundtrip tests for request types

* request builder tests

* move request_builder -> request::builder

* get network tests working

* return only complete headers responses

* request builder improvements

* New version of jsonrpc.

* split request filling into fill,complete

* Better invalid encoding messages

* Fixing deprecated methods of tokio_core

* use PIP messages in on_demand, old API

* migrate oneshot::complete to send in on_demand

* get on_demand tests to compile

* port ethsync to PIP messages

* adjust to minor on_demand API changes in RPC

* Using dedicated branch for jsonrpc

* Bump

ethcore/light/Cargo.toml

@@ -1,5 +1,5 @@
 [package]
-description = "Parity LES primitives"
+description = "Parity Light Client Implementation"
 homepage = "http://parity.io"
 license = "GPL-3.0"
 name = "ethcore-light"

ethcore/light/src/client/header_chain.rs

@@ -24,7 +24,6 @@
 //!   - It stores only headers (and a pruned subset of them)
 //!   - To allow for flexibility in the database layout once that's incorporated.
 // TODO: use DB instead of memory. DB Layout: just the contents of `candidates`/`headers`
-//
 
 use std::collections::{BTreeMap, HashMap};
 

ethcore/light/src/client/mod.rs

@@ -31,7 +31,7 @@ use ethcore::service::ClientIoMessage;
 use ethcore::encoded;
 use io::IoChannel;
 
-use util::{Bytes, DBValue, H256, Mutex, RwLock};
+use util::{H256, Mutex, RwLock};
 
 use self::header_chain::{AncestryIter, HeaderChain};
 
@@ -315,50 +315,3 @@ impl LightChainClient for Client {
 		Client::cht_root(self, i)
 	}
 }
-
-// dummy implementation, should be removed when a `TestClient` is added.
-impl ::provider::Provider for Client {
-	fn chain_info(&self) -> BlockChainInfo {
-		Client::chain_info(self)
-	}
-
-	fn reorg_depth(&self, _a: &H256, _b: &H256) -> Option<u64> {
-		None
-	}
-
-	fn earliest_state(&self) -> Option<u64> {
-		None
-	}
-
-	fn block_header(&self, id: BlockId) -> Option<encoded::Header> {
-		Client::block_header(self, id)
-	}
-
-	fn block_body(&self, _id: BlockId) -> Option<encoded::Body> {
-		None
-	}
-
-	fn block_receipts(&self, _hash: &H256) -> Option<Bytes> {
-		None
-	}
-
-	fn state_proof(&self, _req: ::request::StateProof) -> Vec<Bytes> {
-		Vec::new()
-	}
-
-	fn contract_code(&self, _req: ::request::ContractCode) -> Bytes {
-		Vec::new()
-	}
-
-	fn header_proof(&self, _req: ::request::HeaderProof) -> Option<(encoded::Header, Vec<Bytes>)> {
-		None
-	}
-
-	fn transaction_proof(&self, _req: ::request::TransactionProof) -> Option<Vec<DBValue>> {
-		None
-	}
-
-	fn ready_transactions(&self) -> Vec<::ethcore::transaction::PendingTransaction> {
-		Vec::new()
-	}
-}

ethcore/light/src/lib.rs

@@ -26,7 +26,7 @@
 //! use-cases like sending transactions from a personal account.
 //!
 //! The light client performs a header-only sync, doing verification and pruning
-//! historical blocks. Upon pruning, batches of 2048 blocks have a number => hash
+//! historical blocks. Upon pruning, batches of 2048 blocks have a number => (hash, TD)
 //! mapping sealed into "canonical hash tries" which can later be used to verify
 //! historical block queries from peers.
 
@@ -57,7 +57,7 @@ mod types;
 
 pub use self::provider::Provider;
 pub use self::transaction_queue::TransactionQueue;
-pub use types::les_request as request;
+pub use types::request as request;
 
 #[macro_use]
 extern crate log;

ethcore/light/src/net/context.rs

@@ -12,15 +12,15 @@
 // 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/>.
+// along with Parity. If not, see <http://www.gnu.org/licenses/>.
 
 //! I/O and event context generalizations.
 
 use network::{NetworkContext, PeerId, NodeId};
 
 use super::{Announcement, LightProtocol, ReqId};
 use super::error::Error;
-use request::{self, Request};
+use request::Requests;
 
 /// An I/O context which allows sending and receiving packets as well as
 /// disconnecting peers. This is used as a generalization of the portions
@@ -50,13 +50,13 @@ pub trait IoContext {
 impl<'a> IoContext for NetworkContext<'a> {
 	fn send(&self, peer: PeerId, packet_id: u8, packet_body: Vec<u8>) {
 		if let Err(e) = self.send(peer, packet_id, packet_body) {
-			debug!(target: "les", "Error sending packet to peer {}: {}", peer, e);
+			debug!(target: "pip", "Error sending packet to peer {}: {}", peer, e);
 		}
 	}
 
 	fn respond(&self, packet_id: u8, packet_body: Vec<u8>) {
 		if let Err(e) = self.respond(packet_id, packet_body) {
-			debug!(target: "les", "Error responding to peer message: {}", e);
+			debug!(target: "pip", "Error responding to peer message: {}", e);
 		}
 	}
 
@@ -83,16 +83,17 @@ pub trait BasicContext {
 	fn persistent_peer_id(&self, peer: PeerId) -> Option<NodeId>;
 
 	/// Make a request from a peer.
-	fn request_from(&self, peer: PeerId, request: Request) -> Result<ReqId, Error>;
+	///
+	/// Fails on: nonexistent peer, network error, peer not server,
+	/// insufficient credits. Does not check capabilities before sending.
+	/// On success, returns a request id which can later be coordinated
+	/// with an event.
+	fn request_from(&self, peer: PeerId, request: Requests) -> Result<ReqId, Error>;
 
 	/// Make an announcement of new capabilities to the rest of the peers.
 	// TODO: maybe just put this on a timer in LightProtocol?
 	fn make_announcement(&self, announcement: Announcement);
 
-	/// Find the maximum number of requests of a specific type which can be made from
-	/// supplied peer.
-	fn max_requests(&self, peer: PeerId, kind: request::Kind) -> usize;
-
 	/// Disconnect a peer.
 	fn disconnect_peer(&self, peer: PeerId);
 
@@ -123,18 +124,14 @@ impl<'a> BasicContext for TickCtx<'a> {
 		self.io.persistent_peer_id(id)
 	}
 
-	fn request_from(&self, peer: PeerId, request: Request) -> Result<ReqId, Error> {
-		self.proto.request_from(self.io, &peer, request)
+	fn request_from(&self, peer: PeerId, requests: Requests) -> Result<ReqId, Error> {
+		self.proto.request_from(self.io, &peer, requests)
 	}
 
 	fn make_announcement(&self, announcement: Announcement) {
 		self.proto.make_announcement(self.io, announcement);
 	}
 
-	fn max_requests(&self, peer: PeerId, kind: request::Kind) -> usize {
-		self.proto.max_requests(peer, kind)
-	}
-
 	fn disconnect_peer(&self, peer: PeerId) {
 		self.io.disconnect_peer(peer);
 	}
@@ -160,18 +157,14 @@ impl<'a> BasicContext for Ctx<'a> {
 		self.io.persistent_peer_id(id)
 	}
 
-	fn request_from(&self, peer: PeerId, request: Request) -> Result<ReqId, Error> {
-		self.proto.request_from(self.io, &peer, request)
+	fn request_from(&self, peer: PeerId, requests: Requests) -> Result<ReqId, Error> {
+		self.proto.request_from(self.io, &peer, requests)
 	}
 
 	fn make_announcement(&self, announcement: Announcement) {
 		self.proto.make_announcement(self.io, announcement);
 	}
 
-	fn max_requests(&self, peer: PeerId, kind: request::Kind) -> usize {
-		self.proto.max_requests(peer, kind)
-	}
-
 	fn disconnect_peer(&self, peer: PeerId) {
 		self.io.disconnect_peer(peer);
 	}

ethcore/light/src/net/error.rs

@@ -56,6 +56,8 @@ pub enum Error {
 	UnknownPeer,
 	/// Unsolicited response.
 	UnsolicitedResponse,
+	/// Bad back-reference in request.
+	BadBackReference,
 	/// Not a server.
 	NotServer,
 	/// Unsupported protocol version.
@@ -78,6 +80,7 @@ impl Error {
 			Error::WrongNetwork => Punishment::Disable,
 			Error::UnknownPeer => Punishment::Disconnect,
 			Error::UnsolicitedResponse => Punishment::Disable,
+			Error::BadBackReference => Punishment::Disable,
 			Error::NotServer => Punishment::Disable,
 			Error::UnsupportedProtocolVersion(_) => Punishment::Disable,
 			Error::BadProtocolVersion => Punishment::Disable,
@@ -109,6 +112,7 @@ impl fmt::Display for Error {
 			Error::WrongNetwork => write!(f, "Wrong network"),
 			Error::UnknownPeer => write!(f, "Unknown peer"),
 			Error::UnsolicitedResponse => write!(f, "Peer provided unsolicited data"),
+			Error::BadBackReference => write!(f, "Bad back-reference in request."),
 			Error::NotServer => write!(f, "Peer not a server."),
 			Error::UnsupportedProtocolVersion(pv) => write!(f, "Unsupported protocol version: {}", pv),
 			Error::BadProtocolVersion => write!(f, "Bad protocol version in handshake"),