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;
}

function uniqueObjectR(v) {
    var used = {};
    var res = [];

    for (var i = 0; i < v.length; i++) {
        var value = v[i];
        if (!used.hasOwnProperty(value)) {
            used[value] = true;
            res.push(value);
        }
    }

    return res;
}

// 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;
}

function uniqueSortR(v) {
    var res = v.slice().sort(function(a, b) {
        return a - b;
    });
    var last = res[0];

    for (var i = 1, k = 1; i < res.length; i++) {
        var value = res[i];

        if (last !== value) {
            last = value;
            res[k++] = value;
        }
    }

    res.length = k;

    return res;
}

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

function uniqueSetR(v) {
    return [...new Set(v)];
}

function uniqueSetR2(v) {
    var used = new Set();
    var res = [];

    for (var i = 0; i < v.length; i++) {
        var value = v[i];
        if (!used.has(value)) {
            used.add(value);
            res.push(value);
        }
    }

    return res;
}

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

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

// High-resolution time
function hrtime(note, start) {
    var timeDiff = process.hrtime(start);
    console.log('\n\033[33m' + note + '\033[37m');
    console.log('Time', parseInt(timeDiff[0] * 1e3 + timeDiff[1] / 1e6) + 'ms');
}

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

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

    // Result
    hrtime(name, start);
    console.log('MemoryUsage', String(process.memoryUsage().heapUsed - mem).replace(/(\d{3})(\d{3})?$/, function(m, a, b){
        return ' ' + a + (b ? ' ' + b : '');
    }) + ' bytes');
    // console.log(fn(source), source);
}

// Params
var source = getRandomArray(1000, 10);
var limit = 50000;

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

// Testcases
testcase('Testcase#object', source, uniqueObject);
testcase('Testcase#objectR', source, uniqueObjectR);
testcase('Testcase#sort', source, uniqueSort);
testcase('Testcase#sortR', source, uniqueSortR);
testcase('Testcase#Set', source, uniqueSet);
testcase('Testcase#SetR', source, uniqueSetR);
testcase('Testcase#SetR2', source, uniqueSetR2);