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
// 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/>.

use crate::types::{ExtendedPeerInfo, SyncEvent, SyncEventStream, SyncStatus, SyncStatusProvider};

use futures::{channel::oneshot, Stream};
use sc_network_types::PeerId;

use sc_consensus::{BlockImportError, BlockImportStatus, JustificationSyncLink, Link};
use sc_network::{NetworkBlock, NetworkSyncForkRequest};
use sc_utils::mpsc::{tracing_unbounded, TracingUnboundedSender};
use sp_runtime::traits::{Block as BlockT, NumberFor};

use std::{
	pin::Pin,
	sync::{
		atomic::{AtomicBool, AtomicUsize, Ordering},
		Arc,
	},
};

/// Commands send to `SyncingEngine`
pub enum ToServiceCommand<B: BlockT> {
	SetSyncForkRequest(Vec<PeerId>, B::Hash, NumberFor<B>),
	RequestJustification(B::Hash, NumberFor<B>),
	ClearJustificationRequests,
	BlocksProcessed(
		usize,
		usize,
		Vec<(Result<BlockImportStatus<NumberFor<B>>, BlockImportError>, B::Hash)>,
	),
	JustificationImported(PeerId, B::Hash, NumberFor<B>, bool),
	AnnounceBlock(B::Hash, Option<Vec<u8>>),
	NewBestBlockImported(B::Hash, NumberFor<B>),
	EventStream(TracingUnboundedSender<SyncEvent>),
	Status(oneshot::Sender<SyncStatus<B>>),
	NumActivePeers(oneshot::Sender<usize>),
	NumDownloadedBlocks(oneshot::Sender<usize>),
	NumSyncRequests(oneshot::Sender<usize>),
	PeersInfo(oneshot::Sender<Vec<(PeerId, ExtendedPeerInfo<B>)>>),
	OnBlockFinalized(B::Hash, B::Header),
	// Status {
	// 	pending_response: oneshot::Sender<SyncStatus<B>>,
	// },
}

/// Handle for communicating with `SyncingEngine` asynchronously
#[derive(Clone)]
pub struct SyncingService<B: BlockT> {
	tx: TracingUnboundedSender<ToServiceCommand<B>>,
	/// Number of peers we're connected to.
	num_connected: Arc<AtomicUsize>,
	/// Are we actively catching up with the chain?
	is_major_syncing: Arc<AtomicBool>,
}

impl<B: BlockT> SyncingService<B> {
	/// Create new handle
	pub fn new(
		tx: TracingUnboundedSender<ToServiceCommand<B>>,
		num_connected: Arc<AtomicUsize>,
		is_major_syncing: Arc<AtomicBool>,
	) -> Self {
		Self { tx, num_connected, is_major_syncing }
	}

	/// Get the number of peers known to `SyncingEngine` (both full and light).
	pub fn num_connected_peers(&self) -> usize {
		self.num_connected.load(Ordering::Relaxed)
	}

	/// Get the number of active peers.
	pub async fn num_active_peers(&self) -> Result<usize, oneshot::Canceled> {
		let (tx, rx) = oneshot::channel();
		let _ = self.tx.unbounded_send(ToServiceCommand::NumActivePeers(tx));

		rx.await
	}

	/// Get the number of downloaded blocks.
	pub async fn num_downloaded_blocks(&self) -> Result<usize, oneshot::Canceled> {
		let (tx, rx) = oneshot::channel();
		let _ = self.tx.unbounded_send(ToServiceCommand::NumDownloadedBlocks(tx));

		rx.await
	}

	/// Get the number of sync requests.
	pub async fn num_sync_requests(&self) -> Result<usize, oneshot::Canceled> {
		let (tx, rx) = oneshot::channel();
		let _ = self.tx.unbounded_send(ToServiceCommand::NumSyncRequests(tx));

		rx.await
	}

	/// Get peer information.
	pub async fn peers_info(
		&self,
	) -> Result<Vec<(PeerId, ExtendedPeerInfo<B>)>, oneshot::Canceled> {
		let (tx, rx) = oneshot::channel();
		let _ = self.tx.unbounded_send(ToServiceCommand::PeersInfo(tx));

		rx.await
	}

	/// Notify the `SyncingEngine` that a block has been finalized.
	pub fn on_block_finalized(&self, hash: B::Hash, header: B::Header) {
		let _ = self.tx.unbounded_send(ToServiceCommand::OnBlockFinalized(hash, header));
	}

	/// Get sync status
	///
	/// Returns an error if `SyncingEngine` has terminated.
	pub async fn status(&self) -> Result<SyncStatus<B>, oneshot::Canceled> {
		let (tx, rx) = oneshot::channel();
		let _ = self.tx.unbounded_send(ToServiceCommand::Status(tx));

		rx.await
	}
}

impl<B: BlockT + 'static> NetworkSyncForkRequest<B::Hash, NumberFor<B>> for SyncingService<B> {
	/// Configure an explicit fork sync request.
	///
	/// Note that this function should not be used for recent blocks.
	/// Sync should be able to download all the recent forks normally.
	/// `set_sync_fork_request` should only be used if external code detects that there's
	/// a stale fork missing.
	///
	/// Passing empty `peers` set effectively removes the sync request.
	fn set_sync_fork_request(&self, peers: Vec<PeerId>, hash: B::Hash, number: NumberFor<B>) {
		let _ = self
			.tx
			.unbounded_send(ToServiceCommand::SetSyncForkRequest(peers, hash, number));
	}
}

impl<B: BlockT> JustificationSyncLink<B> for SyncingService<B> {
	/// Request a justification for the given block from the network.
	///
	/// On success, the justification will be passed to the import queue that was part at
	/// initialization as part of the configuration.
	fn request_justification(&self, hash: &B::Hash, number: NumberFor<B>) {
		let _ = self.tx.unbounded_send(ToServiceCommand::RequestJustification(*hash, number));
	}

	fn clear_justification_requests(&self) {
		let _ = self.tx.unbounded_send(ToServiceCommand::ClearJustificationRequests);
	}
}

#[async_trait::async_trait]
impl<B: BlockT> SyncStatusProvider<B> for SyncingService<B> {
	/// Get high-level view of the syncing status.
	async fn status(&self) -> Result<SyncStatus<B>, ()> {
		let (rtx, rrx) = oneshot::channel();

		let _ = self.tx.unbounded_send(ToServiceCommand::Status(rtx));
		rrx.await.map_err(|_| ())
	}
}

impl<B: BlockT> Link<B> for SyncingService<B> {
	fn blocks_processed(
		&self,
		imported: usize,
		count: usize,
		results: Vec<(Result<BlockImportStatus<NumberFor<B>>, BlockImportError>, B::Hash)>,
	) {
		let _ = self
			.tx
			.unbounded_send(ToServiceCommand::BlocksProcessed(imported, count, results));
	}

	fn justification_imported(
		&self,
		who: PeerId,
		hash: &B::Hash,
		number: NumberFor<B>,
		success: bool,
	) {
		let _ = self
			.tx
			.unbounded_send(ToServiceCommand::JustificationImported(who, *hash, number, success));
	}

	fn request_justification(&self, hash: &B::Hash, number: NumberFor<B>) {
		let _ = self.tx.unbounded_send(ToServiceCommand::RequestJustification(*hash, number));
	}
}

impl<B: BlockT> SyncEventStream for SyncingService<B> {
	/// Get syncing event stream.
	fn event_stream(&self, name: &'static str) -> Pin<Box<dyn Stream<Item = SyncEvent> + Send>> {
		let (tx, rx) = tracing_unbounded(name, 100_000);
		let _ = self.tx.unbounded_send(ToServiceCommand::EventStream(tx));
		Box::pin(rx)
	}
}

impl<B: BlockT> NetworkBlock<B::Hash, NumberFor<B>> for SyncingService<B> {
	fn announce_block(&self, hash: B::Hash, data: Option<Vec<u8>>) {
		let _ = self.tx.unbounded_send(ToServiceCommand::AnnounceBlock(hash, data));
	}

	fn new_best_block_imported(&self, hash: B::Hash, number: NumberFor<B>) {
		let _ = self.tx.unbounded_send(ToServiceCommand::NewBestBlockImported(hash, number));
	}
}

impl<B: BlockT> sp_consensus::SyncOracle for SyncingService<B> {
	fn is_major_syncing(&self) -> bool {
		self.is_major_syncing.load(Ordering::Relaxed)
	}

	fn is_offline(&self) -> bool {
		self.num_connected.load(Ordering::Relaxed) == 0
	}
}