Newer
Older
// Copyright 2020 Parity Technologies (UK) Ltd.
// This file is part of Polkadot.
// Polkadot 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.
// Polkadot 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 Polkadot. If not, see <http://www.gnu.org/licenses/>.
//! Utility function to make it easier to connect to validators.
use std::collections::HashMap;
use std::pin::Pin;
use futures::{
task::{Poll, self},
stream,
};
use streamunordered::{StreamUnordered, StreamYield};
use polkadot_node_subsystem::{
errors::RuntimeApiError,
messages::{AllMessages, NetworkBridgeMessage},
SubsystemContext,
};
use polkadot_primitives::v1::{Hash, ValidatorId, AuthorityDiscoveryId, SessionIndex};
use sc_network::PeerId;
/// Utility function to make it easier to connect to validators.
pub async fn connect_to_validators<Context: SubsystemContext>(
ctx: &mut Context,
relay_parent: Hash,
validators: Vec<ValidatorId>,
) -> Result<ConnectionRequest, Error> {
let current_index = crate::request_session_index_for_child_ctx(relay_parent, ctx).await?.await??;
connect_to_past_session_validators(ctx, relay_parent, validators, current_index).await
}
/// Utility function to make it easier to connect to validators in the past sessions.
pub async fn connect_to_past_session_validators<Context: SubsystemContext>(
ctx: &mut Context,
relay_parent: Hash,
validators: Vec<ValidatorId>,
session_index: SessionIndex,
) -> Result<ConnectionRequest, Error> {
let session_info = crate::request_session_info_ctx(
relay_parent,
session_index,
ctx,
).await?.await??;
let (session_validators, discovery_keys) = match session_info {
Some(info) => (info.validators, info.discovery_keys),
None => return Err(RuntimeApiError::from(
format!("No SessionInfo found for the index {}", session_index)
).into()),
};
let id_to_index = session_validators.iter()
.zip(0usize..)
.collect::<HashMap<_, _>>();
// We assume the same ordering in authorities as in validators so we can do an index search
let maybe_authorities: Vec<_> = validators.iter()
.map(|id| {
let validator_index = id_to_index.get(&id);
validator_index.and_then(|i| discovery_keys.get(*i).cloned())
})
.collect();
let authorities: Vec<_> = maybe_authorities.iter()
.cloned()
.filter_map(|id| id)
.collect();
let validator_map = validators.into_iter()
.zip(maybe_authorities.into_iter())
.filter_map(|(k, v)| v.map(|v| (v, k)))
.collect::<HashMap<AuthorityDiscoveryId, ValidatorId>>();
let connections = connect_to_authorities(ctx, authorities).await?;
Ok(ConnectionRequest {
validator_map,
connections,
})
}
async fn connect_to_authorities<Context: SubsystemContext>(
ctx: &mut Context,
validator_ids: Vec<AuthorityDiscoveryId>,
) -> Result<mpsc::Receiver<(AuthorityDiscoveryId, PeerId)>, Error> {
const PEERS_CAPACITY: usize = 8;
let (connected, connected_rx) = mpsc::channel(PEERS_CAPACITY);
ctx.send_message(AllMessages::NetworkBridge(
NetworkBridgeMessage::ConnectToValidators {
validator_ids,
connected,
}
/// A struct that assists performing multiple concurrent connection requests.
///
/// This allows concurrent connections to validator sets at different `relay_parents`
/// and multiplexes their results into a single `Stream`.
#[derive(Default)]
pub struct ConnectionRequests {
// added connection requests relay_parent -> StreamUnordered token
id_map: HashMap<Hash, usize>,
// Connection requests themselves.
requests: StreamUnordered<ConnectionRequest>,
}
impl stream::FusedStream for ConnectionRequests {
fn is_terminated(&self) -> bool {
false
}
}
impl ConnectionRequests {
/// Insert a new connection request.
///
/// If a `ConnectionRequest` under a given `relay_parent` already exists it will
/// be revoked and substituted with a new one.
pub fn put(&mut self, relay_parent: Hash, request: ConnectionRequest) {
self.remove(&relay_parent);
let token = self.requests.push(request);
self.id_map.insert(relay_parent, token);
}
/// Remove a connection request by a given `relay_parent`.
pub fn remove(&mut self, relay_parent: &Hash) {
if let Some(token) = self.id_map.remove(relay_parent) {
Pin::new(&mut self.requests).remove(token);
}
}
/// Is a connection at this relay parent already present in the request
pub fn contains_request(&self, relay_parent: &Hash) -> bool {
self.id_map.contains_key(relay_parent)
}
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
}
impl stream::Stream for ConnectionRequests {
/// (relay_parent, validator_id, peer_id).
type Item = (Hash, ValidatorId, PeerId);
fn poll_next(mut self: Pin<&mut Self>, cx: &mut task::Context) -> Poll<Option<Self::Item>> {
// If there are currently no requests going on, pend instead of
// polling `StreamUnordered` which would lead to it terminating
// and returning `Poll::Ready(None)`.
if self.requests.is_empty() {
return Poll::Pending;
}
match Pin::new(&mut self.requests).poll_next(cx) {
Poll::Ready(Some((yielded, token))) => {
match yielded {
StreamYield::Item(item) => {
if let Some((relay_parent, _)) = self.id_map.iter()
.find(|(_, &val)| val == token)
{
return Poll::Ready(Some((*relay_parent, item.0, item.1)));
}
}
StreamYield::Finished(_) => {
// `ConnectionRequest` is fullfilled, but not revoked
}
}
},
_ => {},
}
Poll::Pending
}
}
/// A pending connection request to validators.
/// This struct implements `Stream` to allow for asynchronous
/// discovery of validator addresses.
///
/// NOTE: the request will be revoked on drop.
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
#[must_use = "dropping a request will result in its immediate revokation"]
pub struct ConnectionRequest {
validator_map: HashMap<AuthorityDiscoveryId, ValidatorId>,
#[must_use = "streams do nothing unless polled"]
connections: mpsc::Receiver<(AuthorityDiscoveryId, PeerId)>,
}
impl stream::Stream for ConnectionRequest {
type Item = (ValidatorId, PeerId);
fn poll_next(mut self: Pin<&mut Self>, cx: &mut task::Context) -> Poll<Option<Self::Item>> {
if self.validator_map.is_empty() {
return Poll::Ready(None);
}
match Pin::new(&mut self.connections).poll_next(cx) {
Poll::Ready(Some((id, peer_id))) => {
if let Some(validator_id) = self.validator_map.remove(&id) {
return Poll::Ready(Some((validator_id, peer_id)));
} else {
// unknown authority_id
// should be unreachable
}
}
_ => {},
}
Poll::Pending
}
}
#[cfg(test)]
mod tests {
use super::*;
use polkadot_primitives::v1::ValidatorPair;
use sp_core::{Pair, Public};
use futures::{executor, poll, StreamExt, SinkExt};
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
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
#[test]
fn adding_a_connection_request_works() {
let mut connection_requests = ConnectionRequests::default();
executor::block_on(async move {
assert_eq!(poll!(Pin::new(&mut connection_requests).next()), Poll::Pending);
let validator_1 = ValidatorPair::generate().0.public();
let validator_2 = ValidatorPair::generate().0.public();
let auth_1 = AuthorityDiscoveryId::from_slice(&[1; 32]);
let auth_2 = AuthorityDiscoveryId::from_slice(&[2; 32]);
let mut validator_map = HashMap::new();
validator_map.insert(auth_1.clone(), validator_1.clone());
validator_map.insert(auth_2.clone(), validator_2.clone());
let (mut rq1_tx, rq1_rx) = mpsc::channel(8);
let peer_id_1 = PeerId::random();
let peer_id_2 = PeerId::random();
let connection_request_1 = ConnectionRequest {
validator_map,
connections: rq1_rx,
};
let relay_parent_1 = Hash::repeat_byte(1);
connection_requests.put(relay_parent_1.clone(), connection_request_1);
rq1_tx.send((auth_1, peer_id_1.clone())).await.unwrap();
rq1_tx.send((auth_2, peer_id_2.clone())).await.unwrap();
let res = Pin::new(&mut connection_requests).next().await.unwrap();
assert_eq!(res, (relay_parent_1, validator_1, peer_id_1));
let res = Pin::new(&mut connection_requests).next().await.unwrap();
assert_eq!(res, (relay_parent_1, validator_2, peer_id_2));
assert_eq!(
poll!(Pin::new(&mut connection_requests).next()),
Poll::Pending,
);
});
}
#[test]
fn adding_two_connection_requests_works() {
let mut connection_requests = ConnectionRequests::default();
executor::block_on(async move {
assert_eq!(poll!(Pin::new(&mut connection_requests).next()), Poll::Pending);
let validator_1 = ValidatorPair::generate().0.public();
let validator_2 = ValidatorPair::generate().0.public();
let auth_1 = AuthorityDiscoveryId::from_slice(&[1; 32]);
let auth_2 = AuthorityDiscoveryId::from_slice(&[2; 32]);
let mut validator_map_1 = HashMap::new();
let mut validator_map_2 = HashMap::new();
validator_map_1.insert(auth_1.clone(), validator_1.clone());
validator_map_2.insert(auth_2.clone(), validator_2.clone());
let (mut rq1_tx, rq1_rx) = mpsc::channel(8);
let (mut rq2_tx, rq2_rx) = mpsc::channel(8);
let peer_id_1 = PeerId::random();
let peer_id_2 = PeerId::random();
let connection_request_1 = ConnectionRequest {
validator_map: validator_map_1,
connections: rq1_rx,
};
let connection_request_2 = ConnectionRequest {
validator_map: validator_map_2,
connections: rq2_rx,
};
let relay_parent_1 = Hash::repeat_byte(1);
let relay_parent_2 = Hash::repeat_byte(2);
connection_requests.put(relay_parent_1.clone(), connection_request_1);
connection_requests.put(relay_parent_2.clone(), connection_request_2);
rq1_tx.send((auth_1, peer_id_1.clone())).await.unwrap();
rq2_tx.send((auth_2, peer_id_2.clone())).await.unwrap();
let res = Pin::new(&mut connection_requests).next().await.unwrap();
assert_eq!(res, (relay_parent_1, validator_1, peer_id_1));
let res = Pin::new(&mut connection_requests).next().await.unwrap();
assert_eq!(res, (relay_parent_2, validator_2, peer_id_2));
assert_eq!(
poll!(Pin::new(&mut connection_requests).next()),
Poll::Pending,
);
});
}
#[test]
fn replacing_a_connection_request_works() {
let mut connection_requests = ConnectionRequests::default();
executor::block_on(async move {
assert_eq!(poll!(Pin::new(&mut connection_requests).next()), Poll::Pending);
let validator_1 = ValidatorPair::generate().0.public();
let validator_2 = ValidatorPair::generate().0.public();
let auth_1 = AuthorityDiscoveryId::from_slice(&[1; 32]);
let auth_2 = AuthorityDiscoveryId::from_slice(&[2; 32]);
let mut validator_map_1 = HashMap::new();
let mut validator_map_2 = HashMap::new();
validator_map_1.insert(auth_1.clone(), validator_1.clone());
validator_map_2.insert(auth_2.clone(), validator_2.clone());
let (mut rq1_tx, rq1_rx) = mpsc::channel(8);
let (mut rq2_tx, rq2_rx) = mpsc::channel(8);
let peer_id_1 = PeerId::random();
let peer_id_2 = PeerId::random();
let connection_request_1 = ConnectionRequest {
validator_map: validator_map_1,
connections: rq1_rx,
};
let connection_request_2 = ConnectionRequest {
validator_map: validator_map_2,
connections: rq2_rx,
};
let relay_parent = Hash::repeat_byte(3);
connection_requests.put(relay_parent.clone(), connection_request_1);
rq1_tx.send((auth_1.clone(), peer_id_1.clone())).await.unwrap();
let res = Pin::new(&mut connection_requests).next().await.unwrap();
assert_eq!(res, (relay_parent, validator_1, peer_id_1.clone()));
connection_requests.put(relay_parent.clone(), connection_request_2);
assert!(rq1_tx.send((auth_1, peer_id_1.clone())).await.is_err());
rq2_tx.send((auth_2, peer_id_2.clone())).await.unwrap();
let res = Pin::new(&mut connection_requests).next().await.unwrap();
assert_eq!(res, (relay_parent, validator_2, peer_id_2));
assert_eq!(
poll!(Pin::new(&mut connection_requests).next()),
Poll::Pending,
);
});
}
}