memo for range & entries

packages/api-derive/src/staking/erasExposure.ts

@@ -7,7 +7,7 @@ import { Exposure } from '@polkadot/types/interfaces';
 import { DeriveEraExposure, DeriveEraExposures, DeriveEraPointsAll, DeriveEraValPoints } from '../types';
 
 import { Observable, combineLatest, of } from 'rxjs';
-import { map, switchMap } from 'rxjs/operators';
+import { map, switchMap, take } from 'rxjs/operators';
 import { StorageKey } from '@polkadot/types';
 
 import { memo } from '../util';
@@ -35,7 +35,7 @@ export function erasExposure (api: ApiInterfaceRx): (withActive?: boolean) => Ob
             // we could just do entries over the full set, however the set can be quite large - split it into
             // batches - may need to re-visit this, or alternatively use pages keys for exceptionally large sets
             allPoints.map(({ era }): Observable<[StorageKey, Exposure][]> =>
-              api.query.staking.erasStakers.entries(era)
+              api.query.staking.erasStakers.entries(era).pipe(take(1))
             )
           )
         ])

packages/api-derive/src/staking/erasPoints.ts

@@ -7,7 +7,7 @@ import { ActiveEraInfo, Balance, EraIndex, EraRewardPoints } from '@polkadot/typ
 import { DeriveEraPointsAll, DeriveEraValPoints } from '../types';
 
 import { Observable, combineLatest, of } from 'rxjs';
-import { map, switchMap } from 'rxjs/operators';
+import { map, switchMap, take } from 'rxjs/operators';
 import { Option, u32 } from '@polkadot/types';
 
 import { memo } from '../util';
@@ -53,10 +53,10 @@ export function erasPoints (api: ApiInterfaceRx): (withActive?: boolean) => Obse
         combineLatest([
           of(indexes),
           indexes.length
-            ? api.query.staking.erasRewardPoints.multi<EraRewardPoints>(indexes)
+            ? api.query.staking.erasRewardPoints.multi<EraRewardPoints>(indexes).pipe(take(1))
             : of([]),
           indexes.length
-            ? api.query.staking.erasValidatorReward.multi<Option<Balance>>(indexes)
+            ? api.query.staking.erasValidatorReward.multi<Option<Balance>>(indexes).pipe(take(1))
             : of([])
         ])
       ),

packages/api-derive/src/staking/validators.ts

@@ -7,7 +7,7 @@ import { AccountId, Exposure } from '@polkadot/types/interfaces';
 import { DeriveStakingValidators } from '../types';
 
 import { Observable, combineLatest, of } from 'rxjs';
-import { map, switchMap } from 'rxjs/operators';
+import { map, switchMap, take } from 'rxjs/operators';
 import { StorageKey } from '@polkadot/types';
 
 import { memo } from '../util';
@@ -17,7 +17,7 @@ function queryNextStakers (api: ApiInterfaceRx): Observable<AccountId[]> {
   // subscriptions, so we need a trigger - currentIndex acts as that trigger to refresh
   return api.derive.session.indexes().pipe(
     switchMap(({ activeEra }): Observable<[StorageKey, Exposure][]> =>
-      api.query.staking.erasStakers.entries(activeEra.addn(1))
+      api.query.staking.erasStakers.entries(activeEra.addn(1)).pipe(take(1))
     ),
     map((entries): AccountId[] =>
       entries.map(([key]): AccountId => key.args[1] as AccountId)