Benchmark: RegExp literal cache or not

Script Preparation code:

var text = ['Micheal', '<a>Haha</a>'];
var RE_HTML_TAG = /<[^>]+>/;

Tests:

Cache
text.map(function(x){ RE_HTML_TAG.test(x) });
No cache
text.map(function(x){ /<[^>]+>/.test(x) });

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Cache
No cache

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 4 months ago)

User agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:146.0) Gecko/20100101 Firefox/146.0

Browser/OS: Firefox 146 on Ubuntu

View result in a separate tab

Test name	Executions per second
Cache	19734314.0 Ops/sec
No cache	15913800.0 Ops/sec

Autogenerated LLM Summary (model llama3.2:3b, generated one year ago):

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark definition and test cases to understand what is being tested.

**Benchmark Definition:**

The website uses JavaScript microbenchmarks, specifically targeting performance-related aspects of regular expression (RegExp) usage in JavaScript.

The benchmark definition consists of two variations:

1. **Cache**: This option involves creating a cached version of the RegExp object using `var RE_HTML_TAG = /<[^>]+>/;`. The cache stores the compiled RegExp pattern for future use, which should reduce overhead by avoiding repeated pattern compilation.
2. **No Cache**: In this variation, no caching is used, and the RegExp pattern is recompiled every time it's needed.

**Options Compared:**

The benchmark compares two approaches:

1. Using a cached RegExp object (`var RE_HTML_TAG = /<[^>]+>/;`)
2. Not using a cached RegExp object (i.e., recompiling the pattern every time)

**Pros and Cons:**

* **Cached RegExp Object (Cache)**:
	+ Pros:
		- Reduced overhead due to reduced pattern compilation.
		- Can lead to better performance in benchmarking, as repeated patterns are not compiled multiple times.
	+ Cons:
		- May incur additional memory usage due to stored cached patterns.
		- Could potentially increase memory leaks if the cache is not properly cleaned up.
* **No Cached RegExp Object (No Cache)**:
	+ Pros:
		- Lowers memory usage, reducing the risk of memory leaks.
	+ Cons:
		- Increases overhead due to repeated pattern compilation.

**Library and Purpose:**

The `RegExp` object in JavaScript provides a built-in mechanism for creating regular expression patterns. The `test()` method is used to check if the subject string matches the pattern. In this benchmark, both variations use the same `test()` method, but with different caching strategies.

**Special JS Feature or Syntax:**

This benchmark does not explicitly mention any special JavaScript features or syntax beyond the standard `RegExp` object usage.

**Other Alternatives:**

If you're interested in exploring other approaches or alternatives to this benchmark, consider the following:

* Using a Just-In-Time (JIT) compiler like SpiderMonkey (for Firefox) or V8 (for Chrome) to optimize RegExp performance.
* Investigating other caching strategies, such as memoization or lazy evaluation.
* Examining alternative regular expression libraries or frameworks that might offer improved performance or features.

In summary, this benchmark compares two caching strategies for RegExp objects in JavaScript: using a cached object versus not using one. The results should provide insights into the performance implications of these approaches and help identify potential optimization opportunities.

Related benchmarks:

RegExp literal cache or not (version: 1)

Comparing performance of: Cache vs No cache

Created: 6 years ago by: Registered User

Jump to the latest result

Cache

No cache

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated one year ago):