fiftyone.pipeline.engines/lruCache.js

Shared base functionality for implementing engines for the 51Degrees Pipeline API

/* *********************************************************************
 * This Original Work is copyright of 51 Degrees Mobile Experts Limited.
 * Copyright 2026 51 Degrees Mobile Experts Limited, Davidson House,
 * Forbury Square, Reading, Berkshire, United Kingdom RG1 3EU.
 *
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 * (EUPL) v.1.2 and is subject to its terms as set out below.
 *
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 *
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 * clause in Article 5 of the EUPL shall not apply.
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const DataKeyedCache = require('./dataKeyedCache');
const LRU = require('./lru');

/**
 * An instance of DataKeyed cache using a least recently used (LRU) method
 **/
class LRUcache extends DataKeyedCache {
  /**
   * Constructor for LRUcache
   *
   * @param {object} options options for the lru cache
   * @param {number} options.size maximum entries in the cache
   */
  constructor ({ size = 100 }) {
    super(...arguments);

    this.cache = new LRU(size);
  }

  get (cacheKey) {
    return this.cache.read(cacheKey);
  }

  put (cacheKey, value) {
    this.cache.write(cacheKey, value);
  }
}

module.exports = LRUcache;