Benchmark: Accessing Values from ArrayBuffer 2

Script Preparation code:

var size = 0xFF - 1;
var buffer = new ArrayBuffer(size);

var dataview = new DataView(buffer);
var uint16array = new Uint16Array(buffer);

Tests:

With new DataView
for (let i = 0; i < size/2; i++) { new DataView(buffer, 2*i).getUint16(0) }
With new UInt16Array
for (let i = 0; i< size/2; i++) { new Uint16Array(buffer, 2*i)[0] }
With constructed DataView
for (let i = 0; i< size/2; i++) { dataview.getUint16(2*i) }
With constructed UInt16Array
for (let i = 0; i< size/2 ; i++) { uint16array[i] }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
With new DataView
With new UInt16Array
With constructed DataView
With constructed UInt16Array

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/105.0.0.0 Safari/537.36

Browser/OS: Chrome 105 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
With new DataView	42588.5 Ops/sec
With new UInt16Array	50093.0 Ops/sec
With constructed DataView	102511.1 Ops/sec
With constructed UInt16Array	102108.5 Ops/sec

Autogenerated LLM Summary (model llama3.2:3b, generated 6 months ago):

LLMs can make mistakes. Check important info.

Let's break down the benchmark and its components.

**Benchmark Overview**

The provided JSON represents a JavaScript microbenchmark test case, specifically designed to compare the performance of different approaches for accessing values from an ArrayBuffer. The test creates a large ArrayBuffer with 512 bytes (0xFF - 1), then defines four different benchmarking scenarios:

* Creating a DataView from the ArrayBuffer and using it to access values.
* Creating a Uint16Array from the ArrayBuffer and using its elements to access values.

**Library Used**

The test uses two libraries: `DataView` and `Uint16Array`. These are part of the Web APIs, specifically designed for working with binary data in JavaScript. `DataView` allows direct access to the raw byte data of an ArrayBuffer, while `Uint16Array` provides a typed array representation of 16-bit unsigned integers.

**JavaScript Features/ Syntax**

The test uses modern JavaScript features, such as:

* Let statements (`let i = 0;`)
* For loops (`for (let i = 0; i < size/2; i++) {}`)
* Template literals (e.g., `\r\n` for line breaks)

However, no special or experimental JavaScript features are used in this benchmark.

**Benchmarking Options**

The test compares four different approaches:

1. **Constructing a DataView**: Creating a new `DataView` instance from the ArrayBuffer and using its methods (`getUint16(2*i)`) to access values.
2. **Using Uint16Array directly**: Creating a new `Uint16Array` instance from the ArrayBuffer, accessing its elements using indexing (`uint16array[i]`), and then using the array's 0th element (`[0]`).
3. **Constructing Uint16Array**: Creating a new `Uint16Array` instance from the ArrayBuffer and using its elements to access values.
4. **Using constructed DataView with indexing**: Similar to option 1, but accessing values using array indexing (`dataview.getUint16(2*i)`).

**Performance Comparison**

The benchmark results show that:

* Constructing a `DataView` with methods is the fastest approach ( highest executions per second).
* Using `Uint16Array` directly is slower than constructing a `DataView`, but faster than using a constructed `Uint16Array`.
* Constructing a `Uint16Array` and accessing its elements using indexing is slower than both approaches above.
* Accessing values using array indexing (`[0]`) on the `Uint16Array` instance is the slowest approach.

**Pros and Cons**

Each approach has its advantages and disadvantages:

* **Constructing a DataView**:
	+ Pros: Direct access to raw data, potentially faster performance.
	+ Cons: Requires more code and understanding of ArrayBuffer manipulation.
* **Using Uint16Array directly**:
	+ Pros: Simple and straightforward implementation, easy to understand.
	+ Cons: May be slower due to the overhead of accessing array elements using indexing.
* **Constructing Uint16Array**:
	+ Pros: Similar performance to `DataView` with methods, easier to implement for those familiar with typed arrays.
	+ Cons: May require more memory allocation and deallocation.

**Alternatives**

If you're looking for alternative approaches or want to optimize your code further, consider the following:

* Use `TypedArray.prototype.subarray()` instead of indexing on a `Uint16Array` instance. This can provide better performance and alignment with the underlying ArrayBuffer.
* Experiment with other Web APIs, such as `WebAssembly`, which provides low-level binary data manipulation capabilities.

Keep in mind that the optimal approach may depend on your specific use case, performance requirements, and personal preference.

Related benchmarks:

Accessing Values from ArrayBuffer 2 (version: 0)

Comparing performance of: With new DataView vs With new UInt16Array vs With constructed DataView vs With constructed UInt16Array

Created: 2 years ago by: Guest

Jump to the latest result

With new DataView

With new UInt16Array

With constructed DataView

With constructed UInt16Array

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 6 months ago):