// node cachemanager
import { caching } from 'cache-manager';
// storage for the cachemanager
import { DiskStoreCache, create } from 'cache-manager-fs-stream';
// initialize caching on disk
const diskstore = create({
  ttl: 60 * 60 /* seconds */,
  maxsize: 1000 * 1000 * 1000 /* max size in bytes on disk */,
  path: 'diskcache',
  binaryEncode: true, // File will be binary encoded (serialized with v8)
  zip: true, // use zip to compress the cache files
});

const diskCache = await caching(diskstore);

// ...
var cacheKey = 'userImageWatermarked:' + user.id + ':' + image.id;
var ttl = 60 * 60 * 24 * 7 * 1000; // in ms

// wrapper function, see more examples at node-cache-manager
const result = diskCache.wrap(
  cacheKey,
  // called if the cache misses in order to generate the value to cache
  async () => {
    // get the image from the database
    return value; // value can be object, Buffer, Stream
  },
  // Options, see node-cache-manager for more examples
  { ttl: ttl },
);

// default values

// time to live in seconds
options.ttl = 60;
// path for cached files
options.path = 'cache/';
// prevent filling of the cache with the files from the cache-directory
options.preventfill = false;
// if true the main cache files will be zipped (not the binary ones)
options.zip = false;
// maximum size of the cache in bytes
options.maxsize = 1000 * 1000 * 1000;
// if true, the binary files are encoded with v8
options.binaryEncode = false;