Benchmark: DataView vs Uint8Array (read bytes)

Script Preparation code:

var size = 0xFF;
var buf = new ArrayBuffer(size);
var view = new DataView(buf);
var byte = new Uint8Array(buf);
var test_sum = 0;

Tests:

read bytes (DataView)
let sum = 0; for (let i=0; i < size; i++) { let val = view.getUint8(i); sum += val; sum |= val; sum ^= val; } test_sum = sum;
read bytes (Uint8Array)
let sum = 0; for (let i=0; i < size; i++) { let val = byte[i]; sum += val; sum |= val; sum ^= val; } test_sum = sum;

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
read bytes (DataView)
read bytes (Uint8Array)

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 17_2_1 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) FxiOS/122.2 Mobile/15E148 Safari/605.1.15

Browser/OS: Mobile Safari 17 on iOS 17.2.1

View result in a separate tab

Test name	Executions per second
read bytes (DataView)	70738.9 Ops/sec
read bytes (Uint8Array)	67769.8 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's dive into the world of JavaScript benchmarks!

**What is tested:**
The provided JSON represents a benchmark test case for comparing two approaches to read bytes from an array buffer: `DataView` and `Uint8Array`. The test checks which approach is faster.

**Options compared:**

1. **DataView**: A typed array that wraps around a mutable ArrayBuffer, allowing direct access to the underlying buffer's data.
2. **Uint8Array**: An untyped array for holding 8-bit unsigned integer values.

**Pros and Cons of each approach:**

* **DataView**:
	+ Pros:
		- Provides direct access to the underlying buffer's data, making it potentially faster.
		- Offers typed array functionality, which can improve performance.
	+ Cons:
		- Requires an ArrayBuffer as its backing store, which might incur additional overhead.
		- Can be less intuitive for some developers due to its abstracted nature.
* **Uint8Array**:
	+ Pros:
		- Is a widely supported and well-understood data type in JavaScript.
		- Does not require an additional buffer object as its backing store, reducing overhead.
	+ Cons:
		- May incur slower performance due to the indirect access pattern.

**Library usage:**
Neither `DataView` nor `Uint8Array` is a separate library; they are built-in data types in JavaScript.

**Special JS feature or syntax:**
The test uses bitwise operators (`|=` and `^=`) as part of its benchmarking logic. These operators have specific meanings:
	+ `|=` performs a bitwise OR assignment.
	+ `^=` performs a bitwise XOR assignment.

These operators are used to calculate the sum of the bytes read from the buffer, taking advantage of the properties of bitwise operations for integer arithmetic.

**Other alternatives:**
If you want to explore alternative approaches or libraries for reading bytes from an array buffer, consider:

* **Canvas**: While not directly related to reading bytes from an array buffer, Canvas can provide a similar abstraction layer for graphics and image data manipulation.
* **WebAssembly**: If you're interested in exploring WebAssembly's ability to manage binary data, it provides more low-level control over data representation.

Keep in mind that these alternatives might not directly compare to the specific use case of `DataView` or `Uint8Array`.

**Benchmark preparation code:**
The script prepares a simple test environment:
1. Allocates an ArrayBuffer with a size of 0xFF (255).
2. Creates a DataView object from this buffer.
3. Creates a Uint8Array object from the same buffer.

These objects will serve as the input for our benchmarking loop, which we'll see in the next step.

Related benchmarks:

DataView vs Uint8Array (read bytes) (version: 0)

Comparing performance of: read bytes (DataView) vs read bytes (Uint8Array)

Created: 5 years ago by: Guest

Jump to the latest result

read bytes (DataView)

read bytes (Uint8Array)

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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