Current File : /opt/alt/alt-nodejs11/root/usr/lib/node_modules/npm/node_modules.bundled/mem//index.js
'use strict';
const mimicFn = require('mimic-fn');
const cacheStore = new WeakMap();
const defaultCacheKey = function (x) {
if (arguments.length === 1 && (x === null || x === undefined || (typeof x !== 'function' && typeof x !== 'object'))) {
return x;
}
return JSON.stringify(arguments);
};
module.exports = (fn, opts) => {
opts = Object.assign({
cacheKey: defaultCacheKey,
cache: new Map()
}, opts);
const memoized = function () {
const cache = cacheStore.get(memoized);
const key = opts.cacheKey.apply(null, arguments);
if (cache.has(key)) {
const c = cache.get(key);
if (typeof opts.maxAge !== 'number' || Date.now() < c.maxAge) {
return c.data;
}
}
const ret = fn.apply(null, arguments);
cache.set(key, {
data: ret,
maxAge: Date.now() + (opts.maxAge || 0)
});
return ret;
};
mimicFn(memoized, fn);
cacheStore.set(memoized, opts.cache);
return memoized;
};
module.exports.clear = fn => {
const cache = cacheStore.get(fn);
if (cache && typeof cache.clear === 'function') {
cache.clear();
}
};
