Benchmark: copy ArrayBuffer: DataView vs Uint8Array.set vs Float64Array.set vs by bytes (2)

Script Preparation code:

var size = 0xFFFF;
var buf = new ArrayBuffer(size);
var view = new DataView(buf);
var byte = new Uint8Array(buf);

var data = new Uint8Array(size);

for (let i = 0; i < size; i++) {
	data[i] = 100*Math.random();
}

Tests:

DataView
for (let i = 0; i < size; i++) { view.setUint8(i, data[i]); }
Uint8Array by byte
for (let i = 0; i < size; i++) { byte[i] = data[i]; }
Uint8Array with set
byte.set(data);
with Float64Array
(new Float64Array(buf, 0, size/8)) .set(new Float64Array(data.buffer, 0, size/8));

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
DataView
Uint8Array by byte
Uint8Array with set
with Float64Array

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 27 days ago):

LLMs can make mistakes. Check important info.

Let's break down the provided JSON and explain what is being tested, the different approaches compared, their pros and cons, and other considerations.

**Benchmark Definition**

The benchmark definition is a script that prepares the test environment. It creates an `ArrayBuffer` with a size of 0xFFFF (65535), a `DataView` object that can be used to access the buffer as a typed array, and a `Uint8Array` object that is initialized from the same buffer.

The script then generates a random data array with the same size as the `ArrayBuffer`. This data will be used in the subsequent test cases to measure performance differences between different approaches.

**Individual Test Cases**

There are four test cases:

1. **DataView**: The test case measures the performance of using a `DataView` object to set each element of the `data` array.
2. **Uint8Array by byte**: This test case measures the performance of setting each element of the `data` array directly on the `byte` array, without using any built-in methods like `set`.
3. **Uint8Array with set**: Similar to the previous test case, but uses the `set` method provided by the `Uint8Array` object.
4. **with Float64Array**: This test case measures the performance of setting each element of the `data` array on a `Float64Array` object created from the same buffer.

**Library and Purpose**

* None of these test cases use any external libraries or dependencies other than JavaScript's built-in functions.
* However, it's worth noting that using `DataView` and `Uint8Array` objects implies the use of typed arrays, which is a feature provided by the Web API.

**Special JS Feature/Syntax**

None of the test cases explicitly use any special JavaScript features or syntax. They are all relatively straightforward implementations of basic array operations.

**Other Considerations**

* The benchmark uses a fixed-size `ArrayBuffer` and generates random data for each iteration, which may not accurately represent real-world scenarios where memory allocation and deallocation can be costly.
* The test cases only measure the performance of setting elements in an array, without considering other aspects like array indexing or manipulation.
* The use of Chrome 112 as the browser in all tests may introduce some bias due to the specific version's implementation.

**Alternatives**

To run a similar benchmark, you could consider using:

1. Browser-specific benchmarking libraries or tools, such as Benchmark.js or jsperf.
2. Node.js with its built-in `bench` module.
3. A framework like Jest or Mocha for running JavaScript tests and benchmarks.

Keep in mind that the specific approach will depend on your needs, the type of performance you want to measure, and the target environment (e.g., web, desktop, mobile).

Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/112.0.0.0 Safari/537.36

Browser/OS: Chrome 112 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
DataView	158.2 Ops/sec
Uint8Array by byte	173.6 Ops/sec
Uint8Array with set	1018924.3 Ops/sec
with Float64Array	964288.8 Ops/sec

Related benchmarks:

copy ArrayBuffer: DataView vs Uint8Array.set vs Float64Array.set vs by bytes (2) (version: 0)

Comparing performance of: DataView vs Uint8Array by byte vs Uint8Array with set vs with Float64Array

Created: one year ago by: Guest

Jump to the latest result

DataView

Uint8Array by byte

Uint8Array with set

with Float64Array

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 27 days ago):