Benchmark: Caching the DateTimeFormatter

Script Preparation code:

var formatter = new Intl.DateTimeFormat('jp', {
    weekday: 'short',
})

Tests:

Un-cached
Intl.DateTimeFormat('jp', { weekday: 'short' }).format(new Date())
Cached
formatter.format(new Date())

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Un-cached
Cached

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 28 days ago):

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark and explain what's being tested, compared, and some considerations.

**Benchmark Definition**

The benchmark is designed to test the performance difference between two approaches: caching and non-caching the creation of an `Intl.DateTimeFormatter` instance. The benchmark definition provides a script preparation code that creates a formatter instance with specific settings (weekday format in Japanese), and two HTML preparation codes, which are empty in this case.

**Test Cases**

There are two test cases:

1. **Un-cached**: This test case runs the `Intl.DateTimeFormat('jp', { weekday: 'short' }).format(new Date())` benchmark definition directly.
2. **Cached**: This test case uses the previously created formatter instance (`formatter`) and runs the `.format(new Date())` method on it.

**Options Compared**

The two approaches being compared are:

1. **Caching**: Creating a new `Intl.DateTimeFormatter` instance every time the benchmark is run.
2. **Non-caching**: Reusing the same formatter instance throughout the test.

**Pros and Cons of Each Approach**

* **Caching (Reusing the Same Instance)**:
	+ Pros:
		- Can lead to faster execution times since only one instance needs to be created.
		- Reduces overhead related to creating new instances.
	+ Cons:
		- May not accurately represent real-world scenarios where instances are recreated frequently.
* **Non-caching (Creating a New Instance Each Time)**:
	+ Pros:
		- More realistic representation of real-world usage, as instances are often recreated for each test run.
	+ Cons:
		- Can lead to slower execution times due to the overhead of creating new instances.

**Library and Purpose**

The `Intl.DateTimeFormatter` library is part of the ECMAScript Internationalization API, which provides support for formatting dates and numbers in various languages. In this benchmark, it's used to format dates with specific locale settings (Japanese).

**Special JS Feature or Syntax**

There are no special JavaScript features or syntax mentioned in the benchmark definition.

**Other Alternatives**

If you were to run a similar benchmark, you might also consider comparing:

* Using a caching mechanism like memoization or a cache library.
* Optimizing the formatter instance creation process (e.g., using a factory function).
* Comparing different locale settings or date formats.

Keep in mind that the specific options and variations will depend on your use case and requirements.

Latest run results:

Run details: (Test run date: 3 years ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 11_2_3) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/89.0.4389.128 Safari/537.36

Browser/OS: Chrome 89 on Mac OS X 11.2.3

View result in a separate tab

Test name	Executions per second
Un-cached	8401.5 Ops/sec
Cached	519036.8 Ops/sec

Related benchmarks:

Caching the DateTimeFormatter (version: 0)

Comparing performance of: Un-cached vs Cached

Created: 3 years ago by: Guest

Jump to the latest result

Un-cached

Cached

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 28 days ago):