<div id="fir" class="hi">
<div id='no' class="ss">
<div id='ff' class="fox">
<button class="target"></button>
<button class="target"></button>
<button class="target"></button>
</div>
</div>
</div>
var cache = {};
var el = document.querySelectorAll('target');
var el = cache['target'];
if (!el) {
el = document.querySelectorAll('target');
cache['target'] = el;
}
--enable-precise-memory-info
flag.
Test case name | Result |
---|---|
uncached | |
cached |
Test name | Executions per second |
---|---|
uncached | 3183545.5 Ops/sec |
cached | 99460488.0 Ops/sec |
Let's break down the provided benchmark and explain what's being tested, compared, and their pros/cons.
Benchmark Overview
The benchmark is designed to test whether caching the querySelector
method makes a difference in the execution time of the code. The benchmark creates two test cases:
document.querySelectorAll('target')
without any caching.var cache = {};
) to store the results of previous executions. If the result is not found in the cache, it executes document.querySelectorAll('target')
and stores the result in the cache.Comparison of Approaches
The two approaches being compared are:
document.querySelectorAll('target')
on every execution, without any caching. The browser has to re-compute the query selector for each execution.document.querySelectorAll('target')
and stores the result in the cache.Pros and Cons
Library and Purpose
In this benchmark, the querySelector
method is a part of the JavaScript DOM API. It's used to select all elements with a given tag name or CSS selector.
The cache library (or rather, the simple cache object created in the script preparation code) is not a separate library, but rather a custom implementation for caching results. This approach allows the benchmark to test whether caching makes a difference without relying on an external library.
Special JS Feature or Syntax
There doesn't appear to be any special JavaScript features or syntax being used in this benchmark. The focus is on testing the caching behavior of the querySelector
method.
Other Alternatives
If you were to implement this benchmark using a different approach, some alternatives could include:
querySelectorAll
with a deep
option or using the querySelector
method in combination with textContent
.Keep in mind that the specific alternatives will depend on the requirements and goals of your benchmark.