| 1 | /** |
| 2 | * Copyright (c) Meta Platforms, Inc. and its affiliates. |
| 3 | * |
| 4 | * This source code is licensed under the MIT license found in the |
| 5 | * LICENSE file in the root directory of this source tree. |
| 6 | * |
| 7 | * @flow |
| 8 | */ |
| 9 | |
| 10 | import {disableClientCache} from 'shared/ReactFeatureFlags'; |
| 11 | import { |
| 12 | cache as cacheImpl, |
| 13 | cacheSignal as cacheSignalImpl, |
| 14 | } from './ReactCacheImpl'; |
| 15 | |
| 16 | function noopCache<A: Iterable<mixed>, T>(fn: (...A) => T): (...A) => T { |
| 17 | // On the client (i.e. not a Server Components environment) `cache` has |
| 18 | // no caching behavior. We just return the function as-is. |
| 19 | // |
| 20 | // We intend to implement client caching in a future major release. In the |
| 21 | // meantime, it's only exposed as an API so that Shared Components can use |
| 22 | // per-request caching on the server without breaking on the client. But it |
| 23 | // does mean they need to be aware of the behavioral difference. |
| 24 | // |
| 25 | // The rest of the behavior is the same as the server implementation — it |
| 26 | // returns a new reference, extra properties like `displayName` are not |
| 27 | // preserved, the length of the new function is 0, etc. That way apps can't |
| 28 | // accidentally depend on those details. |
| 29 | return function () { |
| 30 | // $FlowFixMe[incompatible-type]: We don't want to use rest arguments since we transpile the code. |
| 31 | return fn.apply(null, arguments); |
| 32 | }; |
| 33 | } |
| 34 | |
| 35 | export const cache: typeof noopCache = disableClientCache |
| 36 | ? noopCache |
| 37 | : cacheImpl; |
| 38 | |
| 39 | function noopCacheSignal(): null | AbortSignal { |
| 40 | return null; |
| 41 | } |
| 42 | |
| 43 | export const cacheSignal: () => null | AbortSignal = disableClientCache |
| 44 | ? noopCacheSignal |
| 45 | : cacheSignalImpl; |