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: 2 years ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36

Browser/OS: Chrome 120 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
bytes_to_hex	625.2 Ops/sec
bytesToHex	245.5 Ops/sec
toHexString	219.2 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the provided JSON data for the MeasureThat.net benchmark.

**Benchmark Definition:**
The benchmark definition is a JavaScript function that converts an array of bytes to a hexadecimal string. There are three variants of this function:

1. `bytes_to_hex(arr)`: This function uses a simple loop to iterate over each byte in the input array, convert it to hexadecimal using ASCII codes, and concatenate the results.
2. `bytesToHex(bytes)`: This function is similar to the first one but uses bitwise operations to extract the high and low bytes of each integer value, then converts them to hexadecimal.
3. `toHexString(byteArray)`: This function uses the `map()` method to apply a transformation to each byte in the input array, which extracts the high and low bytes, converts them to hexadecimal, and concatenates the results.

**Options Compared:**
The three variants of the `bytes_to_hex` function are compared in terms of execution speed. The MeasureThat.net benchmark measures the time it takes for each variant to execute a certain number of times (in this case, 100,000).

**Pros and Cons:**

* **`bytes_to_hex(arr)`**: This function is simple and easy to understand. However, it may be slower than the other two variants due to the overhead of using string concatenation.
* **`bytesToHex(bytes)`**: This function uses bitwise operations, which can be faster than string concatenation. However, it requires a basic understanding of bitwise operations and may be less readable than the first variant.
* **`toHexString(byteArray)`**: This function is concise and efficient, but it relies on the `map()` method, which may incur additional overhead compared to simple loops.

**Other Considerations:**

* **Memory Allocation:** The `bytes_to_hex(arr)` function allocates memory for a string variable (`str`) each time it's called. In contrast, the `bytesToHex(bytes)` and `toHexString(byteArray)` functions do not allocate explicit memory.
* **Browser Support:** All three variants should work in modern browsers, but their behavior may vary due to differences in how they handle strings and bitwise operations.

**Library Usage:**
None of the benchmarked functions use any external libraries. However, if we were to write more complex benchmarks, we might consider using libraries like `console.time()` or `performance.now()` for timing measurements, or `string-escape` library for string escaping (although this is not used in the provided benchmark).

**Special JS Features/Syntax:**
There are no special JavaScript features or syntax used in these functions beyond basic arithmetic and loop constructs. The only notable feature is the use of bitwise operations (`&`, `>>>`) in the `bytesToHex(bytes)` function, which may require a brief explanation for developers unfamiliar with this syntax.

**Alternatives:**
If you wanted to write similar benchmarks using different approaches, you could try:

* Using a library like `benchmark.js` or `testify.js` that provides more advanced benchmarking features.
* Implementing the functions in a different language (e.g., Python) and then translating them into JavaScript for comparison.
* Using online tools like `jsperf` or `jsbench` to compare execution speeds.

Related benchmarks:

bytesToHex (version: 0)

Comparing performance of: bytes_to_hex vs bytesToHex vs toHexString

Created: 9 years ago by: Registered User

Jump to the latest result

bytes_to_hex

bytesToHex

toHexString

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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