Run results for: array buffer to hex conversion 6 methods vs base64 2 methods

Run details:

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 18_3_2 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/18.3.1 Mobile/15E148 Safari/604.1

Browser: Mobile Safari 18

Operating system: iOS 18.3.2

Device Platform: Mobile

Date tested: one year ago

Test name	Executions per second
directly set	161614.0 Ops/sec
push values	196980.7 Ops/sec
buf2hex()	67684.2 Ops/sec
precomputed ASCII with shift	44176.9 Ops/sec
array prototype map	168050.5 Ops/sec
base64	334801.2 Ops/sec
base64 loop	436318.1 Ops/sec
string +	305059.6 Ops/sec

Script Preparation code:

var saltVal = crypto.getRandomValues(new Uint8Array(16));

function arrayBufferToHexString(bytes) {
    bytes = new Uint8Array(bytes);
    var hex = new Array(bytes.length);
    for (let i = 0; i < bytes.length; i++) {
        hex[i] = ("0" + bytes[i].toString(16)).slice(-2);
    }
    return hex.join("");
}

function bytesToHexString(bytes) {
    bytes = new Uint8Array(bytes);
    var hexBytes = [];
    for (var i = 0; i < bytes.length; i++) {
        var byteString = bytes[i].toString(16);
        if (byteString.length < 2) byteString = "0" + byteString;
        hexBytes.push(byteString);
    }
    return hexBytes.join("");
}

function buf2hex(buffer) { // buffer is an ArrayBuffer
  return [...new Uint8Array(buffer)]
      .map(x => x.toString(16).padStart(2, '0'))
      .join('');
}

function hex(arrayBuffer)
{
  	const asciiCodes = new Uint8Array(
    	Array.prototype.map.call(
        	"0123456789abcdef",
        	char => char.charCodeAt()
    	)
	);
  
    const buff = new Uint8Array(arrayBuffer);
    const charCodes = new Uint8Array(buff.length * 2);

    for (let i = 0; i < buff.length; ++i)
    {
        charCodes[i * 2] = asciiCodes[buff[i] >>> 4];
        charCodes[i * 2 + 1] = asciiCodes[buff[i] & 0xf];
    }

    return String.fromCharCode(...charCodes);
}

function hex2(arrayBuffer)
{
    return Array.prototype.map.call(
        new Uint8Array(arrayBuffer),
        n => n.toString(16).padStart(2, "0")
    ).join("");
}

function arrayBufferToBase64(buffer) {
  const byteArray = new Uint8Array(buffer);
  const binaryString = byteArray.reduce((acc, byte) => acc + String.fromCharCode(byte), "");
  return btoa(binaryString);
}

function arrayBufferToBase64loop( buffer ) {
    var binary = '';
    var bytes = new Uint8Array( buffer );
    var len = bytes.byteLength;
    for (var i = 0; i < len; i++) {
        binary += String.fromCharCode( bytes[ i ] );
    }
    return window.btoa( binary );
}

function bytesToHexString2(bytes) {
    bytes = new Uint8Array(bytes);
    var hexBytes = '';
    for (var i = 0; i < bytes.length; i++) {
        var byteString = bytes[i].toString(16);
        if (byteString.length < 2) byteString = "0" + byteString;
        hexBytes += byteString;
    }
    return hexBytes;
}

Tests:

directly set
arrayBufferToHexString(saltVal);
push values
bytesToHexString(saltVal)
buf2hex()
buf2hex(saltVal)
precomputed ASCII with shift
hex(saltVal)
array prototype map
hex2(saltVal)
base64
arrayBufferToBase64(saltVal)
base64 loop
arrayBufferToBase64loop(saltVal)
string +
bytesToHexString2(saltVal)

Run results for: array buffer to hex conversion 6 methods vs base64 2 methods

convert array buffer to hex

directly set

push values

buf2hex()

precomputed ASCII with shift

array prototype map

base64

base64 loop

string +