Benchmark: bytesToHex - MeasureThat.net

Script Preparation code:

var arr = [];

var count = 100000;

for(var i = 0; i<count; i++) {
  arr.push(i%255);
}

function bytes_to_hex ( arr ) {
    var str = '';
    for ( var i = 0; i < arr.length; i++ ) {
        var h = ( arr[i] & 0xff ).toString(16);
        if ( h.length < 2 ) str += '0';
        str += h;
    }
    return str;
}

function bytesToHex(bytes) {
	for (var hex = [], i = 0; i < bytes.length; i++) {
		hex.push((bytes[i] >>> 4).toString(16));
		hex.push((bytes[i] & 0xF).toString(16));
	}
	return hex.join("");
}

function toHexString(byteArray) {
  return byteArray.map(function(byte) {
    return ('0' + (byte & 0xFF).toString(16)).slice(-2);
  }).join('')
}

Tests:

bytes_to_hex
bytes_to_hex(arr);
bytesToHex
bytesToHex(arr);
toHexString
toHexString(arr);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
bytes_to_hex
bytesToHex
toHexString

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/116.0.0.0 Safari/537.36 OPR/102.0.0.0

Browser/OS: Opera 102 on Windows

View result in a separate tab

Test name	Executions per second
bytes_to_hex	957.5 Ops/sec
bytesToHex	249.5 Ops/sec
toHexString	258.1 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's dive into the benchmark and explain what's being tested.

**Benchmark Overview**

The provided JSON represents a JavaScript microbenchmarking test suite, specifically designed to measure the performance of three different implementations of converting an array of bytes to a hexadecimal string:

1. `bytes_to_hex`
2. `bytesToHex` (with a slight difference in implementation)
3. `toHexString`

**Test Case Breakdown**

Each test case consists of a single benchmark definition, which is executed repeatedly to measure its performance.

* `bytes_to_hex`: This function takes an array as input and returns the hexadecimal representation of each byte. The implementation uses a simple loop to iterate over the array and convert each byte to a hexadecimal string.
* `bytesToHex`: Similar to `bytes_to_hex`, but with some differences in the implementation details (notably, using bitwise shift operations instead of direct string concatenation).
* `toHexString`: This function takes an array as input and returns the hexadecimal representation of each byte. The implementation uses the `map()` method to apply a transformation function to each element of the array.

**Comparison of Options**

The three implementations have different approaches:

1. **`bytes_to_hex`**: Simple loop-based iteration, which can be slow due to the overhead of string concatenation.
2. **`bytesToHex`**: Uses bitwise shift operations to convert bytes to hexadecimal strings, potentially reducing overhead and improving performance.
3. **`toHexString`**: Leverages the `map()` method, which is optimized for performance and allows for more concise code.

**Pros and Cons**

* **`bytes_to_hex`**:
	+ Pros: Simple, easy to understand.
	+ Cons: May be slow due to string concatenation overhead.
* **`bytesToHex`**:
	+ Pros: Potential performance improvement due to bitwise shift operations.
	+ Cons: More complex implementation details, may require more expertise.
* **`toHexString`**:
	+ Pros: Concise code, optimized for performance using `map()`.
	+ Cons: May be less intuitive for beginners.

**Library and Syntax Considerations**

None of the implementations explicitly use any external libraries. However, the `bytesToHex` function uses bitwise shift operations (`>>> 4`) to convert bytes to hexadecimal strings, which is a common pattern in JavaScript.

No special JS features or syntax are used beyond standard ECMAScript 2022 (ES22) support.

**Alternative Approaches**

Other approaches could be explored, such as:

1. Using `Buffer` objects and the `toString()` method with a radix parameter to convert bytes to hexadecimal strings.
2. Leveraging native WebAssembly (WASM) functions for efficient byte-to-hexadecimal conversions.
3. Employing specialized libraries or modules optimized for performance in JavaScript.

These alternatives would require significant modifications to the benchmark test suite, but could potentially yield even better results.

Keep in mind that microbenchmarking is an art and a science, and different approaches may be more suitable depending on specific use cases and requirements.

Related benchmarks:

bytesToHex (version: 0)

Comparing performance of: bytes_to_hex vs bytesToHex vs toHexString

Created: 8 years ago by: Guest

Jump to the latest result

bytes_to_hex

bytesToHex

toHexString

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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