Benchmark: copy ArrayBuffer: DataView vs Uint8Array.set vs by bytes ag-sockets

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();
}

window._data = data;
window._buf = buf;

Tests:

DataView
data[Date.now()%data.length] = 43; for (let i; i < size; i++) { view.setUint8(i, data[i]); }
Uint8Array by byte
data[Date.now()%data.length] = 43; for (let i; i < size; i++) { byte[i] = data[i]; }
Uint8Array with set
data[Date.now()%data.length] = 43; byte.set(new Uint8Array(data.buffer, data.byteOffset, data.length));

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
DataView
Uint8Array by byte
Uint8Array with set

Fastest: N/A

Slowest: N/A

Latest run results:

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

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark and its test cases.

**Benchmark Overview**

The benchmark is testing three different approaches to copy data from an ArrayBuffer to a Uint8Array:

1. Using a DataView to access individual bytes in the ArrayBuffer
2. Setting individual bytes directly on the Uint8Array object
3. Using the `set` method of Uint8Array, which allows copying data from another Uint8Array or ArrayBuffer

**Library and Its Purpose**

In this benchmark, two libraries are used:

1. **Uint8Array**: a built-in JavaScript array that represents an array of 8-bit unsigned integers.
2. **DataView**: a built-in JavaScript object that provides a way to access the contents of an ArrayBuffer.

The DataView is used to access individual bytes in the ArrayBuffer, while Uint8Array is used as the destination array for copying data from the ArrayBuffer.

**Test Cases**

There are three test cases:

1. **DataView**:
	* The benchmark definition uses a DataView to set individual bytes on the Uint8Array object.
	* This approach allows direct access to individual bytes in the ArrayBuffer, which can be beneficial for certain types of operations.
	* However, it may not be as efficient as other approaches due to the overhead of creating and manipulating DataViews.
2. **Uint8Array by byte**:
	* The benchmark definition uses a Uint8Array object and directly sets individual bytes using the `data[i]` syntax.
	* This approach can be less efficient than using a DataView, as it requires indexing into the array for each byte.
3. **Uint8Array with set**:
	* The benchmark definition uses the `set` method of Uint8Array to copy data from an ArrayBuffer.
	* This approach is generally more efficient than setting individual bytes on the array, as it avoids the overhead of indexing and allows for more direct access to the data.

**Pros and Cons**

Here are some pros and cons of each approach:

1. **DataView**:
	+ Pros: allows direct access to individual bytes, can be beneficial for certain types of operations.
	+ Cons: may not be as efficient due to overhead of creating and manipulating DataViews.
2. **Uint8Array by byte**:
	+ Pros: simple and easy to implement.
	+ Cons: less efficient than using a DataView or `set` method.
3. **Uint8Array with set**:
	+ Pros: generally more efficient than setting individual bytes on the array, allows for direct access to data.
	+ Cons: may not be as intuitive for beginners due to its use of a specific method.

**Other Considerations**

* The benchmark results show that the `set` method approach is generally faster than the other two approaches, which is consistent with expectations based on the underlying implementation details.
* The use of a large ArrayBuffer size (`0xFFFF`) may be contributing to the performance differences between the approaches. Smaller sizes might not reveal the same performance differences.

**Alternatives**

If you're looking for alternative approaches or ways to optimize this benchmark, consider:

1. Using a different library or approach, such as `TypedArray` or `WebAssembly`.
2. Optimizing the code by reducing the size of the ArrayBuffer or using more efficient algorithms.
3. Using profiling tools to identify performance bottlenecks in your own code.

Keep in mind that the choice of approach will depend on the specific requirements and constraints of your project.

Related benchmarks:

copy ArrayBuffer: DataView vs Uint8Array.set vs by bytes ag-sockets (version: 0)

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

Created: 4 years ago by: Guest

Jump to the latest result

DataView

Uint8Array by byte

Uint8Array with set

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

No previous run results

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