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    quick-lru
    TypeScript icon, indicating that this package has built-in type declarations

    6.0.0 • Public • Published

    quick-lru Coverage Status

    Simple “Least Recently Used” (LRU) cache

    Useful when you need to cache something and limit memory usage.

    Inspired by the hashlru algorithm, but instead uses Map to support keys of any type, not just strings, and values can be undefined.

    Install

    $ npm install quick-lru
    

    Usage

    import QuickLRU from 'quick-lru';
    
    const lru = new QuickLRU({maxSize: 1000});
    
    lru.set('🦄', '🌈');
    
    lru.has('🦄');
    //=> true
    
    lru.get('🦄');
    //=> '🌈'

    API

    new QuickLRU(options?)

    Returns a new instance.

    options

    Type: object

    maxSize

    Required
    Type: number

    The maximum number of items before evicting the least recently used items.

    maxAge

    Type: number
    Default: Infinity

    The maximum number of milliseconds an item should remain in cache. By default maxAge will be Infinity, which means that items will never expire.

    Lazy expiration happens upon the next write or read call.

    Individual expiration of an item can be specified by the set(key, value, options) method.

    onEviction

    Optional
    Type: (key, value) => void

    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).

    Instance

    The instance is an Iterable of [key, value] pairs so you can use it directly in a for…of loop.

    Both key and value can be of any type.

    .set(key, value, options?)

    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 on the constructor, otherwise the item will never expire.

    .get(key)

    Get an item.

    .has(key)

    Check if an item exists.

    .peek(key)

    Get an item without marking it as recently used.

    .delete(key)

    Delete an item.

    Returns true if the item is removed or false if the item doesn't exist.

    .clear()

    Delete all items.

    .resize(maxSize)

    Update the maxSize, 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.

    .keys()

    Iterable for all the keys.

    .values()

    Iterable for all the values.

    .entriesAscending()

    Iterable for all entries, starting with the oldest (ascending in recency).

    .entriesDescending()

    Iterable for all entries, starting with the newest (descending in recency).

    .size

    The stored item count.

    Related


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    Install

    npm i quick-lru

    DownloadsWeekly Downloads

    11,256,440

    Version

    6.0.0

    License

    MIT

    Unpacked Size

    14.3 kB

    Total Files

    5

    Last publish

    Collaborators

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