38 lines
1.4 KiB
TypeScript
38 lines
1.4 KiB
TypeScript
// Copyright 2017-2021 @polkadot/api-derive authors & contributors
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// SPDX-License-Identifier: Apache-2.0
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import type { ApiInterfaceRx } from '@polkadot/api/types';
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import type { Vec } from '@polkadot/types';
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import type { EventRecord, SignedBlock } from '@polkadot/types/interfaces';
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import type { Observable } from '@polkadot/x-rxjs';
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import type { HeaderExtended, SignedBlockExtended } from '../type/types';
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import { combineLatest, of } from '@polkadot/x-rxjs';
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import { map, switchMap } from '@polkadot/x-rxjs/operators';
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import { createSignedBlockExtended } from '../type';
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import { memo } from '../util';
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/**
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* @name subscribeNewBlocks
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* @returns The latest block & events for that block
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*/
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export function subscribeNewBlocks (instanceId: string, api: ApiInterfaceRx): () => Observable<SignedBlockExtended> {
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return memo(instanceId, (): Observable<SignedBlockExtended> =>
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api.derive.chain.subscribeNewHeads().pipe(
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switchMap((header): Observable<[SignedBlock, Vec<EventRecord>, HeaderExtended]> => {
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const blockHash = header.createdAtHash || header.hash;
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return combineLatest(
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api.rpc.chain.getBlock(blockHash),
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api.query.system.events.at(blockHash),
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of(header)
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);
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}),
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map(([block, events, header]) =>
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createSignedBlockExtended(block.registry, block, events, header.validators)
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)
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)
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);
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}
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