/******************************************************
* Use different arLen and arOb1..arOb4 functions to see
* how per-element memory overhead changes
******************************************************/

var seed = 1, m = 2147483648

function lcr()
{
    seed = (seed * 1103515245 + 12345) % m
    return seed / m
}

var rand = lcr // can be Math.random()

function rc()
{
    return String.fromCharCode(Math.floor(97 + rand() * 26))
}

function key()
{
    var s = ""
    for (var i = 0; i < 6; i++)
    {
        s += rc()
    }
    return s
}

function float()
{
    return Math.round((Math.random() * 2 + 4) * 1000) / 1000
}

function ob_uniq()
{
    var a = {}
    for (var i = 0; i < 10; i++)
    {
        a[key()] = float()
    }
    return a
}

var sameProp = ob_uniq()

function ob_same()
{
    seed = 123
    return ob_uniq()
}

var arLen

function arOb1()
{
    var a = new Array(arLen)
    for (var i = 0; i < a.length; i++)
    {
        a[i] = ob_uniq()
    }
    return a
}

function arOb2()
{
    var a = new Array(arLen)
    for (var i = 0; i < a.length; i++)
    {
        a[i] = ob_same()
    }
    return a
}

function arOb3()
{
    var o = ob_same()

    var a = new Array(arLen)
    for (var i = 0; i < a.length; i++)
    {
        var oo = {}
        for (var p in o)
        {
            oo[p] = float()
        }
        a[i] = oo
    }
    return a
}

function arOb4()
{
    var o = ob_same()
    var a = {}
    for (var p in o)
    {
        a[p] = new Array(arLen)
    }
    for (var i = 0; i < arLen; i++)
    {
        for (var p in o)
        {
            a[p][i] = float()
        }
    }
    return a
}

function getAt(a, idx)
{
    if (a instanceof Array)
    {
        return a[idx]
    }

    var element = {}
    for (var p in a)
    {
        element[p] = a[p][idx]
    }
    return element
}

function usage()
{
    return process.memoryUsage().heapUsed
}

var u0 = usage()
setInterval(function () { console.log(((usage() - u0) / arLen).toFixed(0)) }, 2000)

arLen = 100000
var a = arOb4()
console.log(getAt(a, 2345))