(function(){
"use strict";
function byteArrayToHex(arrayBuffer){
const chunks = [];
(new Uint32Array(arrayBuffer)).forEach(function(num){
chunks.push(num.toString(16));
});
return chunks.map(function(chunk){
return "0".repeat(8 - chunk.length) + chunk;
}).join("");
}
const container = document.getElementById("tests");
const iframe = document.getElementById("iframe");
const template = document.querySelector(".test");
template.parentElement.removeChild(template);
function getElements(){
const doc = iframe.contentDocument;
return Array.from(doc.querySelectorAll(".testRect"));
}
function formatNumber(number){
const str = number.toString();
return "" + str.substring(0, str.length - 2) + "" +
str.substring(str.length - 2);
}
const properties = ["x", "y", "width", "height", "top", "left", "right", "bottom"];
async function performTest(output, callback){
const rects = getElements().map(function(element){
return {
name: element.dataset.name,
data: callback(element)
};
});
const data = new Float64Array(rects.length * properties.length);
rects.forEach(function(rect, i){
properties.forEach(function(property, j){
data[i * properties.length + j] = rect.data[property];
});
});
const hash = await crypto.subtle.digest("SHA-256", data);
output.querySelector(".hash").textContent = byteArrayToHex(hash);
const dataNode = output.querySelector(".data");
dataNode.innerHTML = "
| " +
rects.map(function(rect){
return "" + rect.name + " | ";
}).join("") +
"
---|
hash | " +
rects.map(function(rect){
return " | ";
}).join("") +
"
" +
properties.map(function(property){
return "" + property + " | " + rects.map(function(rect){
return "" +
formatNumber(rect.data[property]) +
" | ";
}).join("") + "
";
}).join("") +
"
";
rects.forEach(async function(rect){
const data = new Float64Array(properties.length);
properties.forEach(function(property, i){
data[i] = rect.data[property];
});
const hash = await crypto.subtle.digest("SHA-256", data);
dataNode.querySelector(
".rectHash[data-name=\"" + rect.name + "\"]"
).textContent = byteArrayToHex(hash);
});
}
function createTest(title, callback){
const output = template.cloneNode(true);
output.querySelector(".title").textContent = title;
output.querySelector(".refresh").addEventListener("click", function(){
performTest(output, callback);
});
output.querySelector(".performance").addEventListener("click", function(){
let count = 200;
let totalCount = 0;
let totalDuration = 0;
return function(){
let duration = 0;
let i = 0;
while (duration < 1000){
const start = Date.now();
for (; i < count; i += 1){
const rects = getElements().map(function(element){
return {
name: element.dataset.name,
data: callback(element)
};
});
const data = new Float64Array(rects.length * properties.length);
rects.forEach(function(rect, i){
properties.forEach(function(property, j){
data[i * properties.length + j] = rect.data[property];
});
});
}
duration += Date.now() - start;
if (duration < 1000){
count += Math.ceil(
count * (1000 - duration) / 1000
);
}
}
totalCount += count;
totalDuration += duration;
alert(
(totalCount / (totalDuration / 1000)).toFixed(2) + " tests/s\n" +
(totalDuration * 1000 / totalCount).toFixed(2) + " µs/test\n" +
"(" + totalCount + " samples)"
);
};
}());
container.appendChild(output);
performTest(output, callback);
}
iframe.addEventListener("load", function(){
createTest("Element.getClientRects", function(element){
return element.getClientRects()[0];
});
createTest("Element.getBoundingClientRect", function(element){
return element.getBoundingClientRect();
});
createTest("Range.getClientRects", function(element){
const range = document.createRange();
range.selectNode(element);
return range.getClientRects()[0];
});
createTest("Range.getBoundingClientRect", function(element){
const range = document.createRange();
range.selectNode(element);
return range.getBoundingClientRect();
});
});
}());