Benchmark: CP437 decode 80000

Script Preparation code:

var n = 80000;
var arr = new Uint8Array(n);
for (let i = 0; i < n; ++i) {
  arr[i] = (Math.random() * 255) | 0;
}


const CP437 = "\0☺☻♥♦♣♠•◘○◙♂♀♪♫☼►◄↕‼¶§▬↨↑↓→←∟↔▲▼ !\"#$%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_`abcdefghijklmnopqrstuvwxyz{|}~⌂ÇüéâäàåçêëèïîìÄÅÉæÆôöòûùÿÖÜ¢£¥₧ƒáíóúñÑªº¿⌐¬½¼¡«»░▒▓│┤╡╢╖╕╣║╗╝╜╛┐└┴┬├─┼╞╟╚╔╩╦╠═╬╧╨╤╥╙╘╒╓╫╪┘┌█▄▌▐▀αßΓπΣσµτΦΘΩδ∞φε∩≡±≥≤⌠⌡÷≈°∙·√ⁿ²■ ".split("");
function convert_in_place(s)
{
	for (let k = 0; k < s.length; k++)
		s[k] = CP437[s[k]];
	return s;
}
function convert(buf)
{
	return convert_in_place(buf.slice());
}

function decodeAppend(buf)
{
	let result = "";
	for (let indexCharacter = 0; indexCharacter < buf.length; indexCharacter++) {
		result += CP437[buf[indexCharacter]];
	}
	return result;
}

function decodeFromCharCode(buf)
{
	const s = convert(buf);
	return String.fromCharCode.apply(null, s);
}

function decodeFromCharCode2(buf, chunk)
{
	let str = "";
	let pad = new Uint8Array(chunk);
	for(let k = 0; k < buf.length; k += chunk)
	{
		const remaining = buf.length - k;
		for (let i = 0; i < Math.min(chunk, remaining); i++)
			pad[i] = CP437[buf[k + i]];
		str += String.fromCharCode.apply(null, remaining < chunk ? pad.subarray(0, remaining) : pad);
	}
	return str;
}

Tests:

append string
decodeAppend(arr)
from char code
decodeFromCharCode(arr)
chunk 100
decodeFromCharCode2(arr, 100)
chunk 1000
decodeFromCharCode2(arr, 1000)
chunk 10000
decodeFromCharCode2(arr, 10000)
chunk 10
decodeFromCharCode2(arr, 10)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
append string
from char code
chunk 100
chunk 1000
chunk 10000
chunk 10

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 25 days ago):

LLMs can make mistakes. Check important info.

Let's break down the benchmark and its options.

**Benchmark Definition**

The benchmark is defined by a JavaScript function that takes an array of bytes as input. The function, named `decodeAppend`, appends the characters represented by the bytes in the array to a string using the CP437 encoding.

**Options Compared**

There are four different implementations of the `decodeAppend` function:

1. `decodeFromCharCode2(arr, chunk)`
2. `decodeFromCharCode2(arr, 1000)`
3. `decodeFromCharCode2(arr, 10000)`
4. `decodeFromCharCode2(arr, 10)`

These functions differ in their approach to decoding the array of bytes:

* `decodeFromCharCode2` with no arguments (or a fixed chunk size) is not provided as an option.
* `decodeFromCharCode2` with a variable chunk size (1000, 10000, or 10). This function processes the input array in chunks and decodes each chunk separately.

**Pros and Cons**

Here are some pros and cons of each approach:

1. **Fixed chunk size**: `decodeFromCharCode2(arr, chunk)`
	* Pros:
		+ May be faster due to reduced overhead from string concatenation.
		+ Can take advantage of caching mechanisms.
	* Cons:
		+ May result in slower performance for smaller input arrays or larger chunks.
		+ Requires careful tuning of the chunk size for optimal performance.
2. **Variable chunk size**: `decodeFromCharCode2(arr, 1000)`, `decodeFromCharCode2(arr, 10000)`, and `decodeFromCharCode2(arr, 10)`
	* Pros:
		+ Can adapt to varying input array sizes and chunk requirements.
		+ May improve performance for larger inputs or smaller chunks.
	* Cons:
		+ May incur additional overhead due to string concatenation and processing in chunks.
		+ Requires more complex logic to handle different chunk sizes.

**CP437 Encoding**

The CP437 encoding is a character encoding standard that maps each byte in the input array to a single Unicode code point. This encoding is commonly used for compatibility with older systems, but it may not provide optimal performance due to its limited range (256 characters) and variable-width representation of some characters.

In summary, the benchmark compares different implementations of the `decodeAppend` function that process the input array in varying chunk sizes. The choice of approach depends on the specific requirements and constraints of the use case.

Latest run results:

Run details: (Test run date: 2 years ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/101.0.4951.64 Safari/537.36

Browser/OS: Chrome 101 on Windows

View result in a separate tab

Test name	Executions per second
append string	718.5 Ops/sec
from char code	29.2 Ops/sec
chunk 100	8.5 Ops/sec
chunk 1000	8.7 Ops/sec
chunk 10000	9.8 Ops/sec
chunk 10	7.1 Ops/sec

Related benchmarks:

CP437 decode 80000 (version: 0)

Comparing performance of: append string vs from char code vs chunk 100 vs chunk 1000 vs chunk 10000 vs chunk 10

Created: 2 years ago by: Guest

Jump to the latest result

append string

from char code

chunk 100

chunk 1000

chunk 10000

chunk 10

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 25 days ago):