topical media & game development
mobile-query-three-plugins-statsplus-statsmemory.js / js
author: mrdoob / mrdoob.com/
author: jetienne / jetienne.com/
var StatsMemory = function (){
var msMin = 100;
var msMax = 0;
var container = document.createElement( 'div' );
container.id = 'stats';
container.style.cssText = 'width:80px;opacity:0.9;cursor:pointer';
var msDiv = document.createElement( 'div' );
msDiv.id = 'ms';
msDiv.style.cssText = 'padding:0 0 3px 3px;text-align:left;background-color:#020;';
container.appendChild( msDiv );
var msText = document.createElement( 'div' );
msText.id = 'msText';
msText.style.cssText = 'color:#0f0;font-family:Helvetica,Arial,sans-serif;font-size:9px;font-weight:bold;line-height:15px';
msText.innerHTML= 'Memory';
msDiv.appendChild( msText );
var msGraph = document.createElement( 'div' );
msGraph.id = 'msGraph';
msGraph.style.cssText = 'position:relative;width:74px;height:30px;background-color:#0f0';
msDiv.appendChild( msGraph );
while ( msGraph.children.length < 74 ) {
var bar = document.createElement( 'span' );
bar.style.cssText = 'width:1px;height:30px;float:left;background-color:#131';
msGraph.appendChild( bar );
}
var updateGraph = function ( dom, height, color ) {
var child = dom.appendChild( dom.firstChild );
child.style.height = height + 'px';
if( color ) child.style.backgroundColor = color;
}
// create an alias in case `window.performance.memory` isnt supported
if( window.performance && window.performance.memory ){
var memory = window.performance.memory;
}else{
var memory = { usedJSHeapSize : 0 };
}
// sanity check -
if( memory.totalJSHeapSize === 0 ){
// open -a "/Applications/Google Chrome.app" --args --enable-memory-info
console.warn('totalJSHeapSize === 0... for chrome use --enable-memory-info. other browsers dont have this feature.')
}
var lastTime = Date.now();
var lastUsedHeap= memory.usedJSHeapSize;
return {
domElement: container,
update: function () {
// refresh only 30time per second
if( Date.now() - lastTime < 1000/30 ) return;
lastTime = Date.now()
var delta = memory.usedJSHeapSize - lastUsedHeap;
lastUsedHeap = memory.usedJSHeapSize;
var color = delta < 0 ? '#830' : '#131';
var ms = memory.usedJSHeapSize
msMin = Math.min( msMin, ms );
msMax = Math.max( msMax, ms );
msText.textContent = "Mem: " + bytesToSize(ms, 2);
var normValue = ms / (30*1024*1024);
var height = Math.min( 30, 30 - normValue * 30 );
updateGraph( msGraph, height, color);
function bytesToSize( bytes, nFractDigit ){
var sizes = ['Bytes', 'KB', 'MB', 'GB', 'TB'];
if (bytes == 0) return 'n/a';
nFractDigit = nFractDigit !== undefined ? nFractDigit : 0;
var precision = Math.pow(10, nFractDigit);
var i = Math.floor(Math.log(bytes) / Math.log(1024));
return Math.round(bytes*precision / Math.pow(1024, i))/precision + ' ' + sizes[i];
};
}
}
};
(C) Æliens
04/09/2009
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