Adding Bridges code as git subtree. (#2515)

* Add instructions.

* Squashed 'bridges/' content from commit 345e84a21

git-subtree-dir: bridges
git-subtree-split: 345e84a2146b56628e9888c9f5e129cb40e868a9

* Remove bridges workspace file to avoid confusing Cargo.

* Add some bridges primitives to Polkadot workspace.

* Improve docs.

polkadot/bridges/relays/rialto-client/Cargo.toml

@@ -0,0 +1,25 @@
+[package]
+name = "relay-rialto-client"
+version = "0.1.0"
+authors = ["Parity Technologies <admin@parity.io>"]
+edition = "2018"
+license = "GPL-3.0-or-later WITH Classpath-exception-2.0"
+
+[dependencies]
+codec = { package = "parity-scale-codec", version = "2.0.0" }
+headers-relay = { path = "../headers-relay" }
+relay-substrate-client = { path = "../substrate-client" }
+relay-utils = { path = "../utils" }
+
+# Bridge dependencies
+
+rialto-runtime = { path = "../../bin/rialto/runtime" }
+
+# Substrate Dependencies
+
+frame-system = { git = "https://github.com/paritytech/substrate.git", branch = "master" }
+frame-support = { git = "https://github.com/paritytech/substrate.git", branch = "master" }
+pallet-transaction-payment = { git = "https://github.com/paritytech/substrate.git", branch = "master" }
+sp-core = { git = "https://github.com/paritytech/substrate.git", branch = "master" }
+sp-keyring = { git = "https://github.com/paritytech/substrate.git", branch = "master" }
+sp-runtime = { git = "https://github.com/paritytech/substrate.git", branch = "master" }

polkadot/bridges/relays/rialto-client/src/lib.rs

@@ -0,0 +1,133 @@
+// Copyright 2019-2020 Parity Technologies (UK) Ltd.
+// This file is part of Parity Bridges Common.
+
+// Parity Bridges Common 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 Bridges Common 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 Bridges Common.  If not, see <http://www.gnu.org/licenses/>.
+
+//! Types used to connect to the Rialto-Substrate chain.
+
+use codec::Encode;
+use relay_substrate_client::{Chain, ChainBase, ChainWithBalances, Client, TransactionSignScheme};
+use sp_core::{storage::StorageKey, Pair};
+use sp_runtime::{generic::SignedPayload, traits::IdentifyAccount};
+use std::time::Duration;
+
+pub use rialto_runtime::BridgeMillauCall;
+
+/// Rialto header id.
+pub type HeaderId = relay_utils::HeaderId<rialto_runtime::Hash, rialto_runtime::BlockNumber>;
+
+/// Rialto chain definition
+#[derive(Debug, Clone, Copy)]
+pub struct Rialto;
+
+impl ChainBase for Rialto {
+	type BlockNumber = rialto_runtime::BlockNumber;
+	type Hash = rialto_runtime::Hash;
+	type Hasher = rialto_runtime::Hashing;
+	type Header = rialto_runtime::Header;
+}
+
+impl Chain for Rialto {
+	const NAME: &'static str = "Rialto";
+	const AVERAGE_BLOCK_INTERVAL: Duration = Duration::from_secs(5);
+
+	type AccountId = rialto_runtime::AccountId;
+	type Index = rialto_runtime::Index;
+	type SignedBlock = rialto_runtime::SignedBlock;
+	type Call = rialto_runtime::Call;
+}
+
+impl ChainWithBalances for Rialto {
+	type NativeBalance = rialto_runtime::Balance;
+
+	fn account_info_storage_key(account_id: &Self::AccountId) -> StorageKey {
+		use frame_support::storage::generator::StorageMap;
+		StorageKey(frame_system::Account::<rialto_runtime::Runtime>::storage_map_final_key(
+			account_id,
+		))
+	}
+}
+
+impl TransactionSignScheme for Rialto {
+	type Chain = Rialto;
+	type AccountKeyPair = sp_core::sr25519::Pair;
+	type SignedTransaction = rialto_runtime::UncheckedExtrinsic;
+
+	fn sign_transaction(
+		client: &Client<Self>,
+		signer: &Self::AccountKeyPair,
+		signer_nonce: <Self::Chain as Chain>::Index,
+		call: <Self::Chain as Chain>::Call,
+	) -> Self::SignedTransaction {
+		let raw_payload = SignedPayload::from_raw(
+			call,
+			(
+				frame_system::CheckSpecVersion::<rialto_runtime::Runtime>::new(),
+				frame_system::CheckTxVersion::<rialto_runtime::Runtime>::new(),
+				frame_system::CheckGenesis::<rialto_runtime::Runtime>::new(),
+				frame_system::CheckEra::<rialto_runtime::Runtime>::from(sp_runtime::generic::Era::Immortal),
+				frame_system::CheckNonce::<rialto_runtime::Runtime>::from(signer_nonce),
+				frame_system::CheckWeight::<rialto_runtime::Runtime>::new(),
+				pallet_transaction_payment::ChargeTransactionPayment::<rialto_runtime::Runtime>::from(0),
+			),
+			(
+				rialto_runtime::VERSION.spec_version,
+				rialto_runtime::VERSION.transaction_version,
+				*client.genesis_hash(),
+				*client.genesis_hash(),
+				(),
+				(),
+				(),
+			),
+		);
+		let signature = raw_payload.using_encoded(|payload| signer.sign(payload));
+		let signer: sp_runtime::MultiSigner = signer.public().into();
+		let (call, extra, _) = raw_payload.deconstruct();
+
+		rialto_runtime::UncheckedExtrinsic::new_signed(call, signer.into_account(), signature.into(), extra)
+	}
+}
+
+/// Rialto signing params.
+#[derive(Clone)]
+pub struct SigningParams {
+	/// Substrate transactions signer.
+	pub signer: sp_core::sr25519::Pair,
+}
+
+impl SigningParams {
+	/// Create signing params from SURI and password.
+	pub fn from_suri(suri: &str, password: Option<&str>) -> Result<Self, sp_core::crypto::SecretStringError> {
+		Ok(SigningParams {
+			signer: sp_core::sr25519::Pair::from_string(suri, password)?,
+		})
+	}
+}
+
+impl std::fmt::Debug for SigningParams {
+	fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+		write!(f, "{}", self.signer.public())
+	}
+}
+
+impl Default for SigningParams {
+	fn default() -> Self {
+		SigningParams {
+			signer: sp_keyring::AccountKeyring::Alice.pair(),
+		}
+	}
+}
+
+/// Rialto header type used in headers sync.
+pub type SyncHeader = relay_substrate_client::SyncHeader<rialto_runtime::Header>;