local_javascript_performance.js

function isSubset(_haystack, _needle, _haystack_length, _needle_length) {
    return new Promise(function(resolve, reject) {
        var i = 0;
        var j = 0;
        for (i = 0; i < _needle_length; i++) {
            for (j = 0; j < _haystack_length; j++) {
                if (_needle[i] == _haystack[j]) {
                    break;
                }
            }
            if (j == _haystack_length) {
                resolve("Absent");
            }
        }
        resolve("Present");
    });
}
var buffer_1 = new ArrayBuffer(20000);
var buffer_2 = new ArrayBuffer(1000000);
var needle = new Uint8Array(buffer_1);
var haystack = new Uint8Array(buffer_2);
needle.fill(222)
haystack.fill(111)
needle_length = needle.length;
haystack_length = haystack.length;
isSubset(haystack, needle, haystack_length, needle_length)
    .then(function(result) {
        console.log("Result: " + result);
    })
    .catch(function() {
        console.log("Error");
    });