33 lines
1.2 KiB
TypeScript
33 lines
1.2 KiB
TypeScript
// Copyright 2017-2020 @polkadot/api-derive authors & contributors
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// SPDX-License-Identifier: Apache-2.0
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import { ApiInterfaceRx } from '@polkadot/api/types';
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import { EventRecord, Hash, SignedBlock } from '@polkadot/types/interfaces';
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import { FullNewBlock } from '../types';
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import { Observable, combineLatest, of } from 'rxjs';
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import { map, switchMap } from 'rxjs/operators';
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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<FullNewBlock> {
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return memo(instanceId, (): Observable<FullNewBlock> =>
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api.derive.chain.subscribeNewHeads().pipe(
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switchMap((header): Observable<[Hash, EventRecord[], SignedBlock]> => {
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const blockHash = header.hash;
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return combineLatest(
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of(blockHash),
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api.query.system.events.at(blockHash),
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api.rpc.chain.getBlock(header.hash)
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);
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}),
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map(([blockHash, events, block]) => ({ block: block.block, blockHash, blockNumber: block.block.header.number.unwrap(), events, justification: block.justification }))
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)
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);
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}
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