Benchmark: Dataview vs Uint8Array - read byte

Script Preparation code:

var size = 1024;
var buffer = new ArrayBuffer(size);
var bytes = new Uint8Array(buffer);
var dv = new DataView(buffer);

for (var i = 0; i < size; i++)
  dv.setUint8(i, Math.ceil(Math.random() * 255));

Tests:

DataView
for (var i = 0; i < size; i++) dv.getUint8(i);
Uint8Array
for (var i = 0; i < size; i++) bytes[i];

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
DataView
Uint8Array

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/137.0.0.0 Safari/537.36

Browser/OS: Chrome 137 on Linux

View result in a separate tab

Test name	Executions per second
DataView	278788.1 Ops/sec
Uint8Array	323897.8 Ops/sec

Autogenerated LLM Summary (model llama3.1:latest, generated one year ago):

LLMs can make mistakes. Check important info.

Let's break down the provided JSON data and benchmark preparation code.

**Benchmark Definition**

The benchmark compares two approaches to read a single byte from a buffer:

1. Using `DataView` (an object that allows for direct manipulation of an ArrayBuffer)
2. Using `Uint8Array` (a typed array that can be used to represent an array of unsigned 8-bit integers)

**Test Case 1: DataView**

The test case uses the following code:
```javascript
for (var i = 0; i < size; i++)
  dv.getUint8(i);
```
Here, `dv` is a `DataView` object created from an ArrayBuffer. The test case simply calls the `getUint8()` method on the `dv` object to read a single byte at each index.

**Test Case 2: Uint8Array**

The test case uses the following code:
```javascript
for (var i = 0; i < size; i++)
  bytes[i];
```
Here, `bytes` is a `Uint8Array` object created from an ArrayBuffer. The test case simply accesses each element of the array using its index.

**Pros and Cons**

* **DataView**
	+ Pros: Direct access to the underlying buffer, can read/write single bytes or larger data types.
	+ Cons: May have performance overhead due to the need to create a `DataView` object and perform bounds checking.
* **Uint8Array**
	+ Pros: A typed array that provides a simple way to access elements using indices. Can be used for large-scale numerical computations.
	+ Cons: May incur performance overhead when accessing individual bytes, as it needs to perform bounds checking.

**Other Considerations**

* The test uses an ArrayBuffer of size 1024 and populates it with random values using `Math.ceil(Math.random() * 255)`. This simulates a real-world scenario where data is being read from or written to memory.
* The test runs for each approach, measuring the number of executions per second (EPS). The EPS value indicates how many times the respective code can execute in one second.

**Alternative Approaches**

Other alternatives for reading single bytes from a buffer include:

1. Using `ArrayBuffer.prototype.slice()` to create a new ArrayBuffer view and access the byte at each index.
2. Using a library like `TypedArrays` or `arraybuffer- viewer` that provides optimized methods for working with ArrayBuffers and typed arrays.

However, these alternatives may incur additional overhead or require more complex code, so they might not be suitable for performance-critical applications.

**Special JS Feature/Syntax**

None are used in this benchmark. The code uses standard JavaScript features like loops, conditionals, and array access.

If you have any further questions or would like me to clarify anything, feel free to ask!

Related benchmarks:

Dataview vs Uint8Array - read byte (version: 0)

Comparing performance of: DataView vs Uint8Array

Created: 7 years ago by: Guest

Jump to the latest result

DataView

Uint8Array

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.1:latest, generated one year ago):