packages/api-derive/src/imOnline/receivedHeartbeats.ts
// Copyright 2017-2024 @polkadot/api-derive authors & contributors
// SPDX-License-Identifier: Apache-2.0
import type { Observable } from 'rxjs';
import type { Option, u32 } from '@polkadot/types';
import type { AccountId } from '@polkadot/types/interfaces';
import type { Codec } from '@polkadot/types/types';
import type { DeriveApi, DeriveHeartbeats } from '../types.js';
import { combineLatest, map, of, switchMap } from 'rxjs';
import { BN_ZERO } from '@polkadot/util';
import { memo } from '../util/index.js';
type Result = [DeriveHeartbeats, AccountId[], Option<Codec>[], u32[]];
function mapResult ([result, validators, heartbeats, numBlocks]: Result): DeriveHeartbeats {
validators.forEach((validator, index): void => {
const validatorId = validator.toString();
const blockCount = numBlocks[index];
const hasMessage = !heartbeats[index].isEmpty;
const prev = result[validatorId];
if (!prev || prev.hasMessage !== hasMessage || !prev.blockCount.eq(blockCount)) {
result[validatorId] = {
blockCount,
hasMessage,
isOnline: hasMessage || blockCount.gt(BN_ZERO)
};
}
});
return result;
}
/**
* @description Return a boolean array indicating whether the passed accounts had received heartbeats in the current session
*/
export function receivedHeartbeats (instanceId: string, api: DeriveApi): () => Observable<DeriveHeartbeats> {
return memo(instanceId, (): Observable<DeriveHeartbeats> =>
api.query.imOnline?.receivedHeartbeats
? api.derive.staking.overview().pipe(
switchMap(({ currentIndex, validators }): Observable<Result> =>
combineLatest([
of({}),
of(validators),
api.query.imOnline.receivedHeartbeats.multi(
validators.map((_address, index) => [currentIndex, index])),
api.query.imOnline.authoredBlocks.multi(
validators.map((address) => [currentIndex, address]))
])
),
map(mapResult)
)
: of({})
);
}