Benchmark: Random hex string generation benchmark

Script Preparation code:

        function genHexString1(len) {
            return Array.from(crypto.getRandomValues(new Uint8Array(len / 2 ))).map(b => b.toString(16).padStart(2, '0')).join('');
        }

        function genHexString2(len) {
            const hex = '0123456789abcdef';
            let output = '';
            for (let i = 0; i < len; ++i) {
                output += hex.charAt(Math.floor(Math.random() * hex.length));
            }
            return output;
        }

        function genHexString3(len) {
            let arr = new Uint8Array((len / 2));
            window.crypto.getRandomValues(arr);
            return Array.from(arr, dec => ('0' + dec.toString(16)).substr(-2)).join('');
        }

        function genHexString4(len) {
            const hexChars = '0123456789abcdef';
            return [...Array(len)].map(() => hexChars[Math.floor(Math.random() * 16)]).join('');
        }

        function genHexString5(len) {
            let arr = new Uint8Array(len / 2);
            crypto.getRandomValues(arr);
            return btoa(String.fromCharCode.apply(null, arr)).replace(/[^a-f0-9]/g, '').substr(0, len);
        }

Tests:

genHexString1
const hex = genHexString1(20)
genHexString2
const hex = genHexString2(20)
genHexString3
const hex = genHexString3(20)
genHexString4
const hex = genHexString4(20)
genHexString5
const hex = genHexString5(20)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
genHexString1
genHexString2
genHexString3
genHexString4
genHexString5

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/113.0.0.0 Safari/537.36

Browser/OS: Chrome 113 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
genHexString1	503242.8 Ops/sec
genHexString2	354289.7 Ops/sec
genHexString3	458107.3 Ops/sec
genHexString4	290037.8 Ops/sec
genHexString5	460392.0 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 world of JavaScript microbenchmarks on MeasureThat.net!

**Benchmark Definition Json**

The provided JSON represents a benchmark definition, which consists of:

1. **Script Preparation Code**: This section contains four functions that generate random hexadecimal strings:
	* `genHexString1(len)`: Uses `crypto.getRandomValues` to generate an array of bytes, converts them to hex, and pads each byte with leading zeros.
	* `genHexString2(len)`: Uses a predefined string `hex` to generate a random hex string by randomly selecting characters from this string.
	* `genHexString3(len)`: Similar to `genHexString1`, but uses the `window.crypto.getRandomValues` API directly.
	* `genHexString4(len)`: Generates a random hex string by randomly selecting characters from a predefined string `hexChars`.
	* `genHexString5(len)`: Uses the `btoa` function to convert an array of bytes to a hex string, which is then truncated to the desired length.
2. **Html Preparation Code**: This section is empty, indicating that no HTML setup or preparation is required for these benchmarks.

**Individual Test Cases**

Each test case represents a single benchmark, where a specific function from the script preparation code is called with a fixed input length (20). The test cases are:

1. `genHexString1`
2. `genHexString2`
3. `genHexString3`
4. `genHexString4`
5. `genHexString5`

These test cases will measure the performance of each function under different conditions.

**Comparison and Options**

The comparison here is between five different approaches to generate random hexadecimal strings:

1. **`genHexString1`**: Uses `crypto.getRandomValues` to generate an array of bytes, converts them to hex, and pads each byte with leading zeros.
	* Pros: Fast and efficient, uses a well-established API for generating random numbers.
	* Cons: May require additional setup or dependencies (e.g., `crypto` module).
2. **`genHexString2`**: Uses a predefined string `hex` to generate a random hex string by randomly selecting characters from this string.
	* Pros: Simple and easy to implement, uses a small, known set of characters.
	* Cons: May produce less diverse or pseudo-random results due to the limited character set.
3. **`genHexString3`**: Similar to `genHexString1`, but uses the `window.crypto.getRandomValues` API directly.
	* Pros: Similar performance characteristics to `genHexString1`.
	* Cons: Same limitations as `genHexString1`.
4. **`genHexString4`**: Generates a random hex string by randomly selecting characters from a predefined string `hexChars`.
	* Pros: Similar simplicity to `genHexString2`, but with a larger character set.
	* Cons: May still produce less diverse or pseudo-random results due to the limited character set.
5. **`genHexString5`**: Uses the `btoa` function to convert an array of bytes to a hex string, which is then truncated to the desired length.
	* Pros: Convenient and easy to implement, uses a widely available API.
	* Cons: May be slower than other approaches due to the overhead of `btoa`.

**Library Usage**

None of the functions in the script preparation code explicitly use any external libraries. However, some browsers (like Chrome) provide APIs like `crypto` or `btoa` that are implemented as part of the browser's JavaScript engine.

**Special JS Feature or Syntax**

There is no explicit usage of special JavaScript features or syntax in this benchmark definition. The code uses standard JavaScript syntax and built-in functions.

**Other Alternatives**

If you were to replace these benchmarks with alternative approaches, some options might include:

* Using a cryptographically secure pseudo-random number generator (CSPRNG) like the `window.crypto.getRandomValues` API.
* Employing a more efficient algorithm for generating random hexadecimal strings, such as the "incrementing counter" method.
* Using a library or framework that provides optimized and tested implementations of random number generation, such as `random.org` or `jsrand`.

Related benchmarks:

Random hex string generation benchmark (version: 0)

Comparing performance of: genHexString1 vs genHexString2 vs genHexString3 vs genHexString4 vs genHexString5

Created: one year ago by: Registered User

Jump to the latest result

genHexString1

genHexString2

genHexString3

genHexString4

genHexString5

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):