referrerpolicy=no-referrer-when-downgrade
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
// This file is part of Substrate.

// Copyright (C) Parity Technologies (UK) Ltd.
// SPDX-License-Identifier: GPL-3.0-or-later WITH Classpath-exception-2.0

// This program 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.

// This program 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 this program. If not, see <https://www.gnu.org/licenses/>.

//! RPC API for BEEFY.

#![warn(missing_docs)]

use parking_lot::RwLock;
use sp_consensus_beefy::AuthorityIdBound;
use std::sync::Arc;

use sc_rpc::{
	utils::{BoundedVecDeque, PendingSubscription},
	SubscriptionTaskExecutor,
};
use sp_application_crypto::RuntimeAppPublic;
use sp_runtime::traits::Block as BlockT;

use futures::{task::SpawnError, FutureExt, StreamExt};
use jsonrpsee::{
	core::async_trait,
	proc_macros::rpc,
	types::{ErrorObject, ErrorObjectOwned},
	PendingSubscriptionSink,
};
use log::warn;

use sc_consensus_beefy::communication::notification::{
	BeefyBestBlockStream, BeefyVersionedFinalityProofStream,
};

mod notification;

#[derive(Debug, thiserror::Error)]
/// Top-level error type for the RPC handler
pub enum Error {
	/// The BEEFY RPC endpoint is not ready.
	#[error("BEEFY RPC endpoint not ready")]
	EndpointNotReady,
	/// The BEEFY RPC background task failed to spawn.
	#[error("BEEFY RPC background task failed to spawn")]
	RpcTaskFailure(#[from] SpawnError),
}

/// The error codes returned by jsonrpc.
pub enum ErrorCode {
	/// Returned when BEEFY RPC endpoint is not ready.
	NotReady = 1,
	/// Returned on BEEFY RPC background task failure.
	TaskFailure = 2,
}

impl From<Error> for ErrorCode {
	fn from(error: Error) -> Self {
		match error {
			Error::EndpointNotReady => ErrorCode::NotReady,
			Error::RpcTaskFailure(_) => ErrorCode::TaskFailure,
		}
	}
}

impl From<Error> for ErrorObjectOwned {
	fn from(error: Error) -> Self {
		let message = error.to_string();
		let code = ErrorCode::from(error);
		ErrorObject::owned(code as i32, message, None::<()>)
	}
}

// Provides RPC methods for interacting with BEEFY.
#[rpc(client, server)]
pub trait BeefyApi<Notification, Hash> {
	/// Returns the block most recently finalized by BEEFY, alongside its justification.
	#[subscription(
		name = "beefy_subscribeJustifications" => "beefy_justifications",
		unsubscribe = "beefy_unsubscribeJustifications",
		item = Notification,
	)]
	fn subscribe_justifications(&self);

	/// Returns hash of the latest BEEFY finalized block as seen by this client.
	///
	/// The latest BEEFY block might not be available if the BEEFY gadget is not running
	/// in the network or if the client is still initializing or syncing with the network.
	/// In such case an error would be returned.
	#[method(name = "beefy_getFinalizedHead")]
	async fn latest_finalized(&self) -> Result<Hash, Error>;
}

/// Implements the BeefyApi RPC trait for interacting with BEEFY.
pub struct Beefy<Block: BlockT, AuthorityId: AuthorityIdBound> {
	finality_proof_stream: BeefyVersionedFinalityProofStream<Block, AuthorityId>,
	beefy_best_block: Arc<RwLock<Option<Block::Hash>>>,
	executor: SubscriptionTaskExecutor,
}

impl<Block, AuthorityId> Beefy<Block, AuthorityId>
where
	Block: BlockT,
	AuthorityId: AuthorityIdBound,
{
	/// Creates a new Beefy Rpc handler instance.
	pub fn new(
		finality_proof_stream: BeefyVersionedFinalityProofStream<Block, AuthorityId>,
		best_block_stream: BeefyBestBlockStream<Block>,
		executor: SubscriptionTaskExecutor,
	) -> Result<Self, Error> {
		let beefy_best_block = Arc::new(RwLock::new(None));

		let stream = best_block_stream.subscribe(100_000);
		let closure_clone = beefy_best_block.clone();
		let future = stream.for_each(move |best_beefy| {
			let async_clone = closure_clone.clone();
			async move { *async_clone.write() = Some(best_beefy) }
		});

		executor.spawn("substrate-rpc-subscription", Some("rpc"), future.map(drop).boxed());
		Ok(Self { finality_proof_stream, beefy_best_block, executor })
	}
}

#[async_trait]
impl<Block, AuthorityId> BeefyApiServer<notification::EncodedVersionedFinalityProof, Block::Hash>
	for Beefy<Block, AuthorityId>
where
	Block: BlockT,
	AuthorityId: AuthorityIdBound,
	<AuthorityId as RuntimeAppPublic>::Signature: Send + Sync,
{
	fn subscribe_justifications(&self, pending: PendingSubscriptionSink) {
		let stream = self
			.finality_proof_stream
			.subscribe(100_000)
			.map(|vfp| notification::EncodedVersionedFinalityProof::new::<Block, AuthorityId>(vfp));

		sc_rpc::utils::spawn_subscription_task(
			&self.executor,
			PendingSubscription::from(pending).pipe_from_stream(stream, BoundedVecDeque::default()),
		);
	}

	async fn latest_finalized(&self) -> Result<Block::Hash, Error> {
		self.beefy_best_block.read().as_ref().cloned().ok_or(Error::EndpointNotReady)
	}
}

#[cfg(test)]
mod tests {
	use super::*;

	use codec::{Decode, Encode};
	use jsonrpsee::{core::EmptyServerParams as EmptyParams, RpcModule};
	use sc_consensus_beefy::{
		communication::notification::BeefyVersionedFinalityProofSender,
		justification::BeefyVersionedFinalityProof,
	};
	use sp_consensus_beefy::{ecdsa_crypto, known_payloads, Payload, SignedCommitment};
	use sp_runtime::traits::{BlakeTwo256, Hash};
	use substrate_test_runtime_client::runtime::Block;

	fn setup_io_handler() -> (
		RpcModule<Beefy<Block, ecdsa_crypto::AuthorityId>>,
		BeefyVersionedFinalityProofSender<Block, ecdsa_crypto::AuthorityId>,
	) {
		let (_, stream) = BeefyBestBlockStream::<Block>::channel();
		setup_io_handler_with_best_block_stream(stream)
	}

	fn setup_io_handler_with_best_block_stream(
		best_block_stream: BeefyBestBlockStream<Block>,
	) -> (
		RpcModule<Beefy<Block, ecdsa_crypto::AuthorityId>>,
		BeefyVersionedFinalityProofSender<Block, ecdsa_crypto::AuthorityId>,
	) {
		let (finality_proof_sender, finality_proof_stream) =
			BeefyVersionedFinalityProofStream::<Block, ecdsa_crypto::AuthorityId>::channel();

		let handler =
			Beefy::new(finality_proof_stream, best_block_stream, sc_rpc::testing::test_executor())
				.expect("Setting up the BEEFY RPC handler works");

		(handler.into_rpc(), finality_proof_sender)
	}

	#[tokio::test]
	async fn uninitialized_rpc_handler() {
		let (rpc, _) = setup_io_handler();
		let request = r#"{"jsonrpc":"2.0","method":"beefy_getFinalizedHead","params":[],"id":1}"#;
		let expected_response = r#"{"jsonrpc":"2.0","id":1,"error":{"code":1,"message":"BEEFY RPC endpoint not ready"}}"#;
		let (response, _) = rpc.raw_json_request(&request, 1).await.unwrap();

		assert_eq!(expected_response, response);
	}

	#[tokio::test]
	async fn latest_finalized_rpc() {
		let (sender, stream) = BeefyBestBlockStream::<Block>::channel();
		let (io, _) = setup_io_handler_with_best_block_stream(stream);

		let hash = BlakeTwo256::hash(b"42");
		let r: Result<(), ()> = sender.notify(|| Ok(hash));
		r.unwrap();

		// Verify RPC `beefy_getFinalizedHead` returns expected hash.
		let request = r#"{"jsonrpc":"2.0","method":"beefy_getFinalizedHead","params":[],"id":1}"#;
		let expected = "{\
			\"jsonrpc\":\"2.0\",\
			\"id\":1,\
			\"result\":\"0x2f0039e93a27221fcf657fb877a1d4f60307106113e885096cb44a461cd0afbf\"\
		}";
		let not_ready: &str = "{\
			\"jsonrpc\":\"2.0\",\
			\"id\":1,\
			\"error\":{\"code\":1,\"message\":\"BEEFY RPC endpoint not ready\"}\
		}";

		let deadline = std::time::Instant::now() + std::time::Duration::from_secs(2);
		while std::time::Instant::now() < deadline {
			let (response, _) = io.raw_json_request(request, 1).await.expect("RPC requests work");
			if response != not_ready {
				assert_eq!(response, expected);
				// Success
				return
			}
			tokio::time::sleep(std::time::Duration::from_millis(50)).await;
		}

		panic!(
			"Deadline reached while waiting for best BEEFY block to update. Perhaps the background task is broken?"
		);
	}

	#[tokio::test]
	async fn subscribe_and_unsubscribe_with_wrong_id() {
		let (rpc, _) = setup_io_handler();
		// Subscribe call.
		let _sub = rpc
			.subscribe_unbounded("beefy_subscribeJustifications", EmptyParams::new())
			.await
			.unwrap();

		// Unsubscribe with wrong ID
		let (response, _) = rpc
			.raw_json_request(
				r#"{"jsonrpc":"2.0","method":"beefy_unsubscribeJustifications","params":["FOO"],"id":1}"#,
				1,
			)
			.await
			.unwrap();
		let expected = r#"{"jsonrpc":"2.0","id":1,"result":false}"#;

		assert_eq!(response, expected);
	}

	fn create_finality_proof() -> BeefyVersionedFinalityProof<Block, ecdsa_crypto::AuthorityId> {
		let payload =
			Payload::from_single_entry(known_payloads::MMR_ROOT_ID, "Hello World!".encode());
		BeefyVersionedFinalityProof::<Block, ecdsa_crypto::AuthorityId>::V1(SignedCommitment {
			commitment: sp_consensus_beefy::Commitment {
				payload,
				block_number: 5,
				validator_set_id: 0,
			},
			signatures: vec![],
		})
	}

	#[tokio::test]
	async fn subscribe_and_listen_to_one_justification() {
		let (rpc, finality_proof_sender) = setup_io_handler();

		// Subscribe
		let mut sub = rpc
			.subscribe_unbounded("beefy_subscribeJustifications", EmptyParams::new())
			.await
			.unwrap();

		// Notify with finality_proof
		let finality_proof = create_finality_proof();
		let r: Result<(), ()> = finality_proof_sender.notify(|| Ok(finality_proof.clone()));
		r.unwrap();

		// Inspect what we received
		let (bytes, recv_sub_id) = sub.next::<sp_core::Bytes>().await.unwrap().unwrap();
		let recv_finality_proof: BeefyVersionedFinalityProof<Block, ecdsa_crypto::AuthorityId> =
			Decode::decode(&mut &bytes[..]).unwrap();
		assert_eq!(&recv_sub_id, sub.subscription_id());
		assert_eq!(recv_finality_proof, finality_proof);
	}
}