Move BEEFY code to consensus (#13484)

* Move beefy primitives to consensus dir
* Move beefy gadget to client consensus folder
* Rename beefy crates

substrate/primitives/consensus/beefy/src/payload.rs

@@ -0,0 +1,105 @@
+// This file is part of Substrate.
+
+// Copyright (C) Parity Technologies (UK) Ltd.
+// SPDX-License-Identifier: Apache-2.0
+
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// 	http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+use codec::{Decode, Encode};
+use scale_info::TypeInfo;
+use sp_runtime::traits::Block;
+use sp_std::prelude::*;
+
+/// Id of different payloads in the [`crate::Commitment`] data.
+pub type BeefyPayloadId = [u8; 2];
+
+/// Registry of all known [`BeefyPayloadId`].
+pub mod known_payloads {
+	use crate::BeefyPayloadId;
+
+	/// A [`Payload`](super::Payload) identifier for Merkle Mountain Range root hash.
+	///
+	/// Encoded value should contain a [`crate::MmrRootHash`] type (i.e. 32-bytes hash).
+	pub const MMR_ROOT_ID: BeefyPayloadId = *b"mh";
+}
+
+/// A BEEFY payload type allowing for future extensibility of adding additional kinds of payloads.
+///
+/// The idea is to store a vector of SCALE-encoded values with an extra identifier.
+/// Identifiers MUST be sorted by the [`BeefyPayloadId`] to allow efficient lookup of expected
+/// value. Duplicated identifiers are disallowed. It's okay for different implementations to only
+/// support a subset of possible values.
+#[derive(Decode, Encode, Debug, PartialEq, Eq, Clone, Ord, PartialOrd, Hash, TypeInfo)]
+pub struct Payload(Vec<(BeefyPayloadId, Vec<u8>)>);
+
+impl Payload {
+	/// Construct a new payload given an initial vallue
+	pub fn from_single_entry(id: BeefyPayloadId, value: Vec<u8>) -> Self {
+		Self(vec![(id, value)])
+	}
+
+	/// Returns a raw payload under given `id`.
+	///
+	/// If the [`BeefyPayloadId`] is not found in the payload `None` is returned.
+	pub fn get_raw(&self, id: &BeefyPayloadId) -> Option<&Vec<u8>> {
+		let index = self.0.binary_search_by(|probe| probe.0.cmp(id)).ok()?;
+		Some(&self.0[index].1)
+	}
+
+	/// Returns a decoded payload value under given `id`.
+	///
+	/// In case the value is not there or it cannot be decoded does not match `None` is returned.
+	pub fn get_decoded<T: Decode>(&self, id: &BeefyPayloadId) -> Option<T> {
+		self.get_raw(id).and_then(|raw| T::decode(&mut &raw[..]).ok())
+	}
+
+	/// Push a `Vec<u8>` with a given id into the payload vec.
+	/// This method will internally sort the payload vec after every push.
+	///
+	/// Returns self to allow for daisy chaining.
+	pub fn push_raw(mut self, id: BeefyPayloadId, value: Vec<u8>) -> Self {
+		self.0.push((id, value));
+		self.0.sort_by_key(|(id, _)| *id);
+		self
+	}
+}
+
+/// Trait for custom BEEFY payload providers.
+pub trait PayloadProvider<B: Block> {
+	/// Provide BEEFY payload if available for `header`.
+	fn payload(&self, header: &B::Header) -> Option<Payload>;
+}
+
+#[cfg(test)]
+mod tests {
+	use super::*;
+
+	#[test]
+	fn payload_methods_work_as_expected() {
+		let id1: BeefyPayloadId = *b"hw";
+		let msg1: String = "1. Hello World!".to_string();
+		let id2: BeefyPayloadId = *b"yb";
+		let msg2: String = "2. Yellow Board!".to_string();
+		let id3: BeefyPayloadId = *b"cs";
+		let msg3: String = "3. Cello Cord!".to_string();
+
+		let payload = Payload::from_single_entry(id1, msg1.encode())
+			.push_raw(id2, msg2.encode())
+			.push_raw(id3, msg3.encode());
+
+		assert_eq!(payload.get_decoded(&id1), Some(msg1));
+		assert_eq!(payload.get_decoded(&id2), Some(msg2));
+		assert_eq!(payload.get_raw(&id3), Some(&msg3.encode()));
+		assert_eq!(payload.get_raw(&known_payloads::MMR_ROOT_ID), None);
+	}
+}