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("");
}

Tests:

bytes_to_hex
bytes_to_hex(arr)
bytesToHex
bytesToHex(arr)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
bytes_to_hex
bytesToHex

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 26 days ago):

LLMs can make mistakes. Check important info.

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

**Benchmark Definition:**
The benchmark defines two JavaScript functions, `bytes_to_hex` and `bytesToHex`, which convert an array of bytes to their hexadecimal representation.

1. **bytes_to_hex(arr)**:
	* This function iterates through each byte in the input array, converts it to its hexadecimal representation using bitwise AND (`&`) with 0xff, pads it with a leading zero if necessary, and appends it to a string.
	* The function returns the resulting hexadecimal string.
2. **bytesToHex(arr)**:
	* This function takes an array of bytes as input and converts each byte to its two-digit hexadecimal representation using bitwise shift (`>>>`) and bitwise AND (`&`) operations.
	* It uses an array `hex` to store the converted bytes, pushes each converted value onto the array, and finally joins the array elements with an empty string to form the final hexadecimal string.

**Options Compared:**
The benchmark is comparing two implementations of the same function, `bytesToHex`, which suggests that there might be a difference in performance or optimization between these two approaches.

**Pros and Cons:**

1. **bytes_to_hex(arr)**:
	* Pros:
		+ May be more straightforward to read and understand due to its simple iteration-based approach.
	* Cons:
		+ Might be slower due to the need for string concatenation, which can lead to overhead in modern JavaScript engines.
2. **bytesToHex(arr)**:
	* Pros:
		+ May be faster since it uses a more efficient way of building strings by storing individual hexadecimal digits in an array and then joining them later.
	* Cons:
		+ The use of bitwise shift (`>>>`) and bitwise AND (`&`) operations might make the code harder to understand for some readers.

**Library Usage:**
There is no explicit library mentioned in the benchmark definition. However, some libraries like `utf-8` or `hex-encoding` are often used for encoding and decoding binary data, but they are not explicitly required here.

**Special JS Feature/Syntax:**
None of the provided functions use any special JavaScript features or syntax that would require additional explanation.

**Other Alternatives:**

1. **Array.prototype.map()**: Instead of using a custom function to convert each byte to its hexadecimal representation, you could use `map()` to create a new array with the converted values.
2. **String.prototype.join()**: Instead of concatenating strings using the `+` operator, you could use `join()` to concatenate the individual hexadecimal digits in an array.

Here's an example implementation that uses `map()` and `join()`:
```javascript
function bytesToHex(arr) {
  return arr.map((b) => (b >>> 4).toString(16) + ((b & 0xF).toString(16))).join('');
}
```
Keep in mind that this is just an alternative implementation, and the original functions might have different performance characteristics or optimizations.

Latest run results:

Run details: (Test run date: 8 years ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.11; rv:49.0) Gecko/20100101 Firefox/49.0

Browser/OS: Firefox 49 on Mac OS X 10.11

View result in a separate tab

Test name	Executions per second
bytes_to_hex	136.0 Ops/sec
bytesToHex	85.5 Ops/sec

Related benchmarks:

bytesToHex (version: 0)

Comparing performance of: bytes_to_hex vs bytesToHex

Created: 8 years ago by: Guest

Jump to the latest result

bytes_to_hex

bytesToHex

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 26 days ago):