sort-vs-object.js

// Unique with use object
function uniqueObject(array) {
    var hash = Object.create(null);
    var result = [];
    var value;

    for (var i = 0; i < array.length; i++) {
        value = array[i];
        if (!hash[value]) {
            hash[value] = true;
            result.push(value);
        }
    }

    return result;
}

// Unique with sort
function uniqueSort(v) {
    var y = [];
    var c = v.slice().sort(function(a, b) {
        return a - b;
    });

    var lastPush = c[0];
    y.push(lastPush);

    for (var j = 0; j < c.length; j++) {
        var value = c[j];

        if (j > 0 && lastPush < value) {
            lastPush = value;
            y.push(value);
        }
    }

    return y;
}

// new Set
function uniqueSet(v) {
    return Array.from(new Set(v));
}

// Get random number
function random(to) {
    return Math.floor(Math.random() * to);
}

// Generate random
function getRandomArray(length, maxNumber) {
    var arr = [];
    for (var i = 0; i < length; i++) {
        arr.push(random(maxNumber));
    }
    return arr;
}

// High-resolution time
function hrtime(note) {
    var end = process.hrtime(start)[1] / 1000000;
    console.log('\n\033[33m' + note + '\033[37m');
    console.log('Time', process.hrtime(start)[0] + 's, ' + end.toFixed(3) + 'ms');
    start = process.hrtime();
}

// Test func.
function testcase(name, source, fn) {
    // Reset
    gc();
    start = process.hrtime();
    // var startMemory = process.memoryUsage().heapUsed;

    // Testing
    for (var i = 0; i < limit; i++) {
        fn(source);
    }

    // Result
    hrtime(name);
    console.log('MemoryUsage', (process.memoryUsage().heapUsed - startMemory) + 'b');
}

// Params
var start = [];
var startMemory = process.memoryUsage().heapUsed;
var source = getRandomArray(1000, 10);
var limit = 500000;

// Output info params
console.log('Iteration — ' + limit);

// Testcases
testcase('Testcase#object', source, uniqueObject);
testcase('Testcase#sort', source, uniqueSort);
testcase('Testcase#Set', source, uniqueSet);

Run

node --expose-gc ./sort-vs-object.js

Изменения и дополнения:

function uniqueObject2(array) {
    var hash = Object.create(null);
    var length = array.length;
    var result = [];
    var value;

    for (var i = 0; i < length; i++) {
        value = array[i];
        if (!hash[value]) {
            hash[value] = true;
            result.push(value);
        }
    }

    return result;
}

function random(to) {
    return Math.floor(Math.random() * to);
}

function getRandomArray(length, maxNumber) {
    var arr = [];
    for (var i = 0; i < length; i++) {
        arr.push(random(maxNumber));
    }
    return arr;
}

var source = getRandomArray(1000, 10);

testcase('Testcase#object2', source, uniqueObject2);

Результат:

Iteration — 500000

Testcase#object
Time 3s, 790.357ms
MemoryUsage 4616592b

Testcase#object2
Time 2s, 580.334ms
MemoryUsage 4985672b

Testcase#sort
Time 22s, 115.686ms
MemoryUsage 3928992b

Testcase#Set
Time 45s, 582.532ms
MemoryUsage 7110944b

PS MemoryUsage показывает неверные данные