Verify header justification during import (#76)

* reshuffle consensus libraries

* polkadot-useful type definitions for statement table

* begin BftService

* primary selection logic

* bft service implementation without I/O

* extract out `BlockImport` trait

* allow bft primitives to compile on wasm

* Block builder (substrate)

* take polkadot-consensus down to the core.

* test for preemption

* fix test build

* Fix wasm build

* Bulid on any block

* Test for block builder.

* Block import tests for client.

* Tidy ups

* clean up block builder instantiation

* justification verification logic

* JustifiedHeader and import

* Propert block generation for tests

* Fixed rpc tests

polkadot/api/src/lib.rs

@@ -28,12 +28,12 @@ extern crate substrate_state_machine as state_machine;
 extern crate error_chain;
 
 use client::backend::Backend;
-use client::blockchain::BlockId;
 use client::Client;
 use polkadot_runtime::runtime;
 use polkadot_executor::Executor as LocalDispatch;
 use substrate_executor::{NativeExecutionDispatch, NativeExecutor};
 use primitives::{AccountId, SessionKey};
+use primitives::block::Id as BlockId;
 use primitives::parachain::DutyRoster;
 
 error_chain! {

polkadot/primitives/src/block.rs

@@ -23,6 +23,8 @@ use rstd::vec::Vec;
 use codec::{Input, Slicable};
 use transaction::UncheckedTransaction;
 
+pub use primitives::block::Id;
+
 /// Used to refer to a block number.
 pub type Number = u64;
 

substrate/bft/Cargo.toml

@@ -5,10 +5,8 @@ authors = ["Parity Technologies <admin@parity.io>"]
 
 [dependencies]
 futures = "0.1.17"
-substrate-client = { path = "../client" }
 substrate-codec = { path = "../codec" }
 substrate-primitives = { path = "../primitives" }
-substrate-state-machine = { path = "../state-machine" }
 ed25519 = { path = "../ed25519" }
 tokio-timer = "0.1.2"
 parking_lot = "0.4"

substrate/bft/src/error.rs

@@ -19,7 +19,7 @@
 error_chain! {
 	errors {
 		/// Missing state at block with given Id.
-		StateUnavailable(b: ::client::BlockId) {
+		StateUnavailable(b: ::primitives::block::Id) {
 			description("State missing at given block."),
 			display("State unavailable at block {:?}", b),
 		}

substrate/bft/src/generic/accumulator.rs

@@ -83,6 +83,13 @@ impl<D, S> UncheckedJustification<D, S> {
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub struct Justification<D,S>(UncheckedJustification<D,S>);
 
+impl<D, S> Justification<D, S> {
+	/// Convert this justification back to unchecked.
+	pub fn uncheck(self) -> UncheckedJustification<D, S> {
+		self.0
+	}
+}
+
 impl<D, S> ::std::ops::Deref for Justification<D, S> {
 	type Target = UncheckedJustification<D, S>;