braid/node_modules/mem/index.d.ts

72 lines
2.2 KiB
TypeScript

export interface CacheStorage<
KeyType extends unknown,
ValueType extends unknown
> {
has(key: KeyType): boolean;
get(key: KeyType): ValueType | undefined;
set(key: KeyType, value: ValueType): void;
delete(key: KeyType): void;
clear?: () => void;
}
export interface Options<
ArgumentsType extends unknown[],
CacheKeyType extends unknown,
ReturnType extends unknown
> {
/**
* Milliseconds until the cache expires.
*
* @default Infinity
*/
readonly maxAge?: number;
/**
* Determines the cache key for storing the result based on the function arguments. By default, if there's only one argument and it's a [primitive](https://developer.mozilla.org/en-US/docs/Glossary/Primitive), it's used directly as a key, otherwise it's all the function arguments JSON stringified as an array.
*
* You could for example change it to only cache on the first argument `x => JSON.stringify(x)`.
*/
readonly cacheKey?: (...arguments: ArgumentsType) => CacheKeyType;
/**
* Use a different cache storage. Must implement the following methods: `.has(key)`, `.get(key)`, `.set(key, value)`, `.delete(key)`, and optionally `.clear()`. You could for example use a `WeakMap` instead or [`quick-lru`](https://github.com/sindresorhus/quick-lru) for a LRU cache.
*
* @default new Map()
*/
readonly cache?: CacheStorage<CacheKeyType, ReturnType>;
/**
* Cache rejected promises.
*
* @default false
*/
readonly cachePromiseRejection?: boolean;
}
/**
* [Memoize](https://en.wikipedia.org/wiki/Memoization) functions - An optimization used to speed up consecutive function calls by caching the result of calls with identical input.
*
* @param fn - Function to be memoized.
*/
declare const mem: {
<
ArgumentsType extends unknown[],
ReturnType extends unknown,
CacheKeyType extends unknown
>(
fn: (...arguments: ArgumentsType) => ReturnType,
options?: Options<ArgumentsType, CacheKeyType, ReturnType>
): (...arguments: ArgumentsType) => ReturnType;
/**
* Clear all cached data of a memoized function.
*
* @param fn - Memoized function.
*/
clear<ArgumentsType extends unknown[], ReturnType extends unknown>(
fn: (...arguments: ArgumentsType) => ReturnType
): void;
};
export default mem;