Benchmark: Uint8Arraybn - MeasureThat.net

Script Preparation code:

var data = [1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9];
var f32 = new Uint8Array(data);
var f33 = f32.buffer;

Tests:

sub
var copy = f32.subarray(10, 20);
sub_buf
var copy = f33.slice(10, 20);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
sub
sub_buf

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 2 years ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/105.0.0.0 Safari/537.36 OPR/91.0.4516.77

Browser/OS: Opera 91 on Windows

View result in a separate tab

Test name	Executions per second
sub	1778806.9 Ops/sec
sub_buf	285749.2 Ops/sec

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

LLMs can make mistakes. Check important info.

**Overview**

MeasureThat.net is a website that allows users to create and run JavaScript microbenchmarks. The provided benchmark definition and test cases are designed to measure the performance of two different approaches for copying subsets of a Uint8Array.

**Benchmark Definition**

The benchmark definition consists of a single script preparation code, which creates a large Uint8Array `data` containing 50 repetitions of a sequence of numbers. It then creates two additional variables: `f32`, a new Uint8Array created from the original data using the `Uint8Array` constructor, and `f33`, which is assigned the value of `f32.buffer`. The script preparation code does not include any HTML code.

**Test Cases**

The benchmark consists of two individual test cases:

1. `sub`: This test case measures the performance of copying a subset of the original Uint8Array using the `subarray` method.
2. `sub_buf`: This test case measures the performance of copying a subset of the original Uint8Array using the `slice` method.

**Options Compared**

The two test cases compare the performance of two different approaches:

1. Using `subarray` (Test Case `sub`)
2. Using `slice` (Test Case `sub_buf`)

**Pros and Cons**

* **Using `subarray`**:
	+ Pros: This approach can be more flexible, as it allows for arbitrary starting and ending indices.
	+ Cons: This approach can be slower, especially when dealing with large arrays, since it requires creating a new array object.
* **Using `slice`**:
	+ Pros: This approach is often faster than using `subarray`, especially for smaller subsets, since it only requires copying a subset of the buffer.
	+ Cons: This approach can be less flexible, as it only allows for fixed starting and ending indices.

**Library: Buffer**

The benchmark uses the built-in `Buffer` class, which is a Node.js module that provides an efficient way to work with binary data. In this case, the `f33` variable is assigned the value of `f32.buffer`, which creates a new buffer object from the `Uint8Array` instance.

**Special JavaScript Feature/ Syntax**

None mentioned in the benchmark definition or test cases.

**Other Alternatives**

If you need to copy subsets of an array, there are other alternatives:

1. Using `map`: You can use the `map` method to create a new array with the desired subset.
2. Using `Array.prototype.slice.call()`: You can use this method to create a new array from a subset of another array.

However, in most cases, using `slice` or `subarray` is still the best approach for copying subsets of an array.

I hope this explanation helps!

Related benchmarks:

Uint8Arraybn (version: 0)

Comparing performance of: sub vs sub_buf

Created: 2 years ago by: Guest

Jump to the latest result

sub

sub_buf

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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