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declare namespace QuickLRU {
interface Options<KeyType, ValueType> {
/**
The maximum number of milliseconds an item should remain in the cache.
@default Infinity
By default, `maxAge` will be `Infinity`, which means that items will never expire.
Lazy expiration upon the next write or read call.
Individual expiration of an item can be specified by the `set(key, value, maxAge)` method.
*/
readonly maxAge?: number;
/**
The maximum number of items before evicting the least recently used items.
*/
readonly maxSize: number;
/**
Called right before an item is evicted from the cache.
Useful for side effects or for items like object URLs that need explicit cleanup (`revokeObjectURL`).
*/
onEviction?: (key: KeyType, value: ValueType) => void;
}
}
declare class QuickLRU<KeyType, ValueType>
implements Iterable<[KeyType, ValueType]> {
/**
The stored item count.
*/
readonly size: number;
/**
Simple ["Least Recently Used" (LRU) cache](https://en.m.wikipedia.org/wiki/Cache_replacement_policies#Least_Recently_Used_.28LRU.29).
The instance is [`iterable`](https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Iteration_protocols) so you can use it directly in a [`for…of`](https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Statements/for...of) loop.
@example
```
import QuickLRU = require('quick-lru');
const lru = new QuickLRU({maxSize: 1000});
lru.set('🦄', '🌈');
lru.has('🦄');
//=> true
lru.get('🦄');
//=> '🌈'
```
*/
constructor(options: QuickLRU.Options<KeyType, ValueType>);
[Symbol.iterator](): IterableIterator<[KeyType, ValueType]>;
/**
Set an item. Returns the instance.
Individual expiration of an item can be specified with the `maxAge` option. If not specified, the global `maxAge` value will be used in case it is specified in the constructor, otherwise the item will never expire.
@returns The list instance.
*/
set(key: KeyType, value: ValueType, options?: {maxAge?: number}): this;
/**
Get an item.
@returns The stored item or `undefined`.
*/
get(key: KeyType): ValueType | undefined;
/**
Check if an item exists.
*/
has(key: KeyType): boolean;
/**
Get an item without marking it as recently used.
@returns The stored item or `undefined`.
*/
peek(key: KeyType): ValueType | undefined;
/**
Delete an item.
@returns `true` if the item is removed or `false` if the item doesn't exist.
*/
delete(key: KeyType): boolean;
/**
Delete all items.
*/
clear(): void;
/**
Update the `maxSize` in-place, discarding items as necessary. Insertion order is mostly preserved, though this is not a strong guarantee.
Useful for on-the-fly tuning of cache sizes in live systems.
*/
resize(maxSize: number): void;
/**
Iterable for all the keys.
*/
keys(): IterableIterator<KeyType>;
/**
Iterable for all the values.
*/
values(): IterableIterator<ValueType>;
/**
Iterable for all entries, starting with the oldest (ascending in recency).
*/
entriesAscending(): IterableIterator<[KeyType, ValueType]>;
/**
Iterable for all entries, starting with the newest (descending in recency).
*/
entriesDescending(): IterableIterator<[KeyType, ValueType]>;
}
export = QuickLRU;
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