@plantinformatics/vcf-genotype-brapi/src/utils/data/cache-node.js

Client and server functions to access genotype data from VCF via a custom web API and BrAPI

// old API is available via require()
// let flatCache = require('flat-cache');
import { /*FlatCache,*/ create } from 'flat-cache';



/* global require */

/* global exports */


/*----------------------------------------------------------------------------*/

/** function API signature generated by ChatGPT, see ./cache-browser.js */
/** Implementation copied from pretzel/lb4app/lb3app/common/utilities/results-cache.js  */
/**
 * File-based persistent cache for Node.js, implemented using flat-cache.
 * @class CacheWrapper
 */
export class CacheWrapper {
  /** If cache is not initialised, initialise it, calling .load().
   * The constructor signature provides the same interface as
   * cache-browser.js.
   *
   * Default cacheDir is .cache in server cwd, i.e. lb4app/lb3app/.cache/
   * (previously : /app/node_modules/flat-cache/.cache) 
   * Default cacheId is cache1 (i.e. file .cache/cache1)
   * Cache format is json.
   * @param {string} dbName
   * @param {string} storeName
   */
  constructor(dbName, storeName) {
    {
      const
      cacheId = storeName,
      cacheDir = './Cache/' + dbName;
      /* old API : cache = flatCache.load(cacheName);
       * cache = new FlatCache();  cache.load(cacheName);
       * Unlike create(), .load() does not set the given name as cacheId
       * (although the function header comment says : If specified `cacheDir`
       * will be used as the directory to persist the data to. refn :
       * node_modules/flat-cache/dist/index.js )
       */
      this.cache = create({ cacheId, cacheDir });
    }
  }

  /**
   * Caches data in a file using flat-cache.
   * @param {string} key - The key to store the data under.
   * @param {any} value - The value to store.
   */
  set(key, value) {
    this.cache.setKey(key, value);
    /** https://github.com/royriojas/flat-cache#readme : "Non visited
     * keys are removed when cache.save() is called" if noPrune is not
     * true
     */
    this.cache.save(/*noPrune*/ true);
  }

  /**
   * Retrieves cached data from flat-cache.
   * @param {string} key - The key to retrieve the data for.
   * @returns {any|null} The cached value or null if not found.
   */
  get(key) {
    let cacheContent = this.cache.getKey(key);
    return cacheContent;
  }
}