move storage keys computation to primitivs (#1254)

bridges/primitives/token-swap/Cargo.toml

@@ -10,18 +10,29 @@ license = "GPL-3.0-or-later WITH Classpath-exception-2.0"
 codec = { package = "parity-scale-codec", version = "2.0.0", default-features = false }
 scale-info = { version = "1.0", default-features = false, features = ["derive"] }
 
+# Bridge Dependencies
+
+bp-runtime = { path = "../runtime", default-features = false }
+
 # Substrate Dependencies
 
 frame-support = { git = "https://github.com/paritytech/substrate", branch = "master", default-features = false }
 sp-core = { git = "https://github.com/paritytech/substrate", branch = "master", default-features = false }
+sp-io = { git = "https://github.com/paritytech/substrate", branch = "master", default-features = false }
 sp-std = { git = "https://github.com/paritytech/substrate", branch = "master", default-features = false }
 
+[dev-dependencies]
+hex = "0.4"
+hex-literal = "0.3"
+
 [features]
 default = ["std"]
 std = [
+	"bp-runtime/std",
 	"codec/std",
 	"frame-support/std",
 	"scale-info/std",
 	"sp-core/std",
+	"sp-io/std",
 	"sp-std/std",
 ]

bridges/primitives/token-swap/src/lib.rs

@@ -16,10 +16,13 @@
 
 #![cfg_attr(not(feature = "std"), no_std)]
 
+pub mod storage_keys;
+
 use codec::{Decode, Encode};
 use frame_support::{weights::Weight, RuntimeDebug};
 use scale_info::TypeInfo;
-use sp_core::U256;
+use sp_core::{H256, U256};
+use sp_io::hashing::blake2_256;
 use sp_std::vec::Vec;
 
 /// Pending token swap state.
@@ -85,6 +88,18 @@ pub struct TokenSwap<ThisBlockNumber, ThisBalance, ThisAccountId, BridgedBalance
 	pub target_account_at_bridged_chain: BridgedAccountId,
 }
 
+impl<ThisBlockNumber, ThisBalance, ThisAccountId, BridgedBalance, BridgedAccountId>
+	TokenSwap<ThisBlockNumber, ThisBalance, ThisAccountId, BridgedBalance, BridgedAccountId>
+where
+	TokenSwap<ThisBlockNumber, ThisBalance, ThisAccountId, BridgedBalance, BridgedAccountId>:
+		Encode,
+{
+	/// Returns hash, used to identify this token swap.
+	pub fn hash(&self) -> H256 {
+		self.using_encoded(blake2_256).into()
+	}
+}
+
 /// SCALE-encoded `Currency::transfer` call on the bridged chain.
 pub type RawBridgedTransferCall = Vec<u8>;
 

bridges/primitives/token-swap/src/storage_keys.rs

@@ -0,0 +1,51 @@
+// Copyright 2019-2021 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/>.
+
+//! Storage keys of bridge token swap pallet.
+
+use frame_support::Identity;
+use sp_core::{storage::StorageKey, H256};
+
+/// Name of the `PendingSwaps` storage map.
+pub const PENDING_SWAPS_MAP_NAME: &str = "PendingSwaps";
+
+/// Storage key of `PendingSwaps` value with given token swap hash.
+pub fn pending_swaps_key(pallet_prefix: &str, token_swap_hash: H256) -> StorageKey {
+	bp_runtime::storage_map_final_key::<Identity>(
+		pallet_prefix,
+		PENDING_SWAPS_MAP_NAME,
+		token_swap_hash.as_ref(),
+	)
+}
+
+#[cfg(test)]
+mod tests {
+	use super::*;
+	use hex_literal::hex;
+
+	#[test]
+	fn pending_swaps_key_computed_properly() {
+		// If this test fails, then something has been changed in module storage that may break
+		// all previous swaps.
+		let storage_key = pending_swaps_key("BridgeTokenSwap", [42u8; 32].into()).0;
+		assert_eq!(
+			storage_key,
+			hex!("76276da64e7a4f454760eedeb4bad11adca2227fef56ad07cc424f1f5d128b9a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a").to_vec(),
+			"Unexpected storage key: {}",
+			hex::encode(&storage_key),
+		);
+	}
+}