packages/api-derive/src/staking/erasRewards.ts
// Copyright 2017-2021 @polkadot/api-derive authors & contributors
// SPDX-License-Identifier: Apache-2.0
import type { ApiInterfaceRx } from '@polkadot/api/types';
import type { Option } from '@polkadot/types';
import type { Balance, EraIndex } from '@polkadot/types/interfaces';
import type { Observable } from '@polkadot/x-rxjs';
import type { DeriveEraRewards } from '../types';
import { of } from '@polkadot/x-rxjs';
import { map, switchMap } from '@polkadot/x-rxjs/operators';
import { deriveCache, memo } from '../util';
import { filterEras } from './util';
const CACHE_KEY = 'eraRewards';
function mapRewards (eras: EraIndex[], optRewards: Option<Balance>[]): DeriveEraRewards[] {
return eras.map((era, index): DeriveEraRewards => ({
era,
eraReward: optRewards[index].unwrapOrDefault()
}));
}
export function _erasRewards (instanceId: string, api: ApiInterfaceRx): (eras: EraIndex[], withActive: boolean) => Observable<DeriveEraRewards[]> {
return memo(instanceId, (eras: EraIndex[], withActive: boolean): Observable<DeriveEraRewards[]> => {
if (!eras.length) {
return of([]);
}
const cached: DeriveEraRewards[] = withActive
? []
: eras
.map((era) => deriveCache.get<DeriveEraRewards>(`${CACHE_KEY}-${era.toString()}`))
.filter((value): value is DeriveEraRewards => !!value);
const remaining = filterEras(eras, cached);
if (!remaining.length) {
return of(cached);
}
return api.query.staking.erasValidatorReward.multi<Option<Balance>>(remaining).pipe(
map((optRewards) => {
const query = mapRewards(remaining, optRewards);
!withActive && query.forEach((q) => deriveCache.set(`${CACHE_KEY}-${q.era.toString()}`, q));
return eras.map((era): DeriveEraRewards =>
cached.find((cached) => era.eq(cached.era)) ||
query.find((query) => era.eq(query.era)) as DeriveEraRewards
);
})
);
});
}
export function erasRewards (instanceId: string, api: ApiInterfaceRx): (withActive?: boolean) => Observable<DeriveEraRewards[]> {
return memo(instanceId, (withActive = false): Observable<DeriveEraRewards[]> =>
api.derive.staking.erasHistoric(withActive).pipe(
switchMap((eras) => api.derive.staking._erasRewards(eras, withActive))
)
);
}