diffusion/src/node_modules/util/memoize.js

Diffusion JavaScript client

/*eslint valid-jsdoc: "off"*/
var a2a = require('./array').argumentsToArray;

function defaultCacheKey(args) {
    return args;
}

/**
 * Wrap a function with an automatic memoization layer.
 *
 * @param {Function} function
 *      - The function to cache results for.
 * @param {Object} [cache={}]
 *      - The internal cache to use.
 * @param {Function} [matcher]
 *      - The matcher function to return a cache key from an array of arguments
 *
 * @returns {Function} The memoized function
 */
function memoize(f, cache, matcher) {
    matcher = matcher || defaultCacheKey;
    cache = cache || {};

    var c = function() {
        var args = a2a(arguments);
        var a = matcher(args);
        var r = cache[a];

        if (r) {
            return r;
        } else {
            r = f.apply(f, args);
        }

        cache[a] = r;
        return r;
    };

    // eslint-disable-next-line no-underscore-dangle
    c._uncached = f;
    return c;
}

module.exports = memoize;