jridgewell/index.html

## index.html
<!DOCTYPE html>
<html>
<head>
	<meta charset="utf-8"/>
	<title>TextEncoder vs charCodeAt</title>
	<script src="https://cdnjs.cloudflare.com/ajax/libs/benchmark/1.0.0/benchmark.min.js"></script>
	<script src="./suite.js"></script>
</head>
<body>
	<h1>Open the console to view the results</h1>
	<h2><code>cmd + alt + j</code> or <code>ctrl + alt + j</code></h2>
</body>
</html>

## suite.js
"use strict";

(function (factory) {
	if (typeof Benchmark !== "undefined") {
		factory(Benchmark);
	} else {
		factory(require("benchmark"));
	}
})(function (Benchmark) {
	var suite = new Benchmark.Suite;

	Benchmark.prototype.setup = function () {
		const shortAscii = 'test'.repeat(100);
		const longAscii = 'test'.repeat(5000);

		const encoder = new TextEncoder();
		function encode(str) {
		    return encoder.encode(str);
		}

		const CONTINUE = 0b1000_0000;
		const TWO_BYTE = 0b1100_0000;
		const THREE_BYTE = 1110_0000;
		const FOUR_BYTE = 0b1111_0000;
		const MASK = 0b11_1111;
		function toBytes(str) {
		  const bytes = new Uint8Array(length(str));

		  let index = 0;
		  for (let i = 0; i < str.length; i++) {
		    const c = str.charCodeAt(0);
		    if (c < 0x80) {
		      bytes[index++] = c;
		      continue;
		    }

		    if (c < 0x800) {
		      bytes[index++] = (c >> 6) | TWO_BYTE;
		      bytes[index++] = (c & MASK) | CONTINUE;
		    }

		    if (
		      (c & 0xfc00) == 0xd800 &&
		      i + 1 < str.length &&
		      (str.charCodeAt(i + 1) & 0xfc00) == 0xdc00
		    ) {
		      // Surrogate Pair
		      c = 0x10000 + ((c & 0x03ff) << 10) + (str.charCodeAt(++i) & 0x03ff);
		      out[index++] = (c >> 18) | FOUR_BYTE;
		      out[index++] = ((c >> 12) & MASK) | CONTINUE;
		      out[index++] = ((c >> 6) & MASK) | CONTINUE;
		      out[index++] = (c & MASK) | CONTINUE;
		      continue;
		    }

		    out[index++] = (c >> 12) | THREE_BYTE;
		    out[index++] = ((c >> 6) & MASK) | CONTINUE;
		    out[index++] = (c & MASK) | CONTINUE;
		    continue;
		  }
		}

		function length(str) {
		  let length = 0;
		  for (let i = 0; i < str.length; i++) {
		    const c = str.charCodeAt(0);
		    if (c < 0x80) {
		      length += 1;
		      continue;
		    }

		    if (c < 0x800) {
		      length += 2;
		      continue;
		    }
		    if (
		      (c & 0xfc00) == 0xd800 &&
		      i + 1 < str.length &&
		      (str.charCodeAt(i + 1) & 0xfc00) == 0xdc00
		    ) {
		      length += 4;
		      continue;
		    }

		    length += 3;
		  }
		  return length;
		}
	};


	suite.add("TextEncoder (short ascii str)", function () {
		// TextEncoder (short ascii str)
		encode(shortAscii);
	});

	suite.add("charCodeAt (short ascii str)", function () {
		// charCodeAt (short ascii str)
		toBytes(shortAscii);
	});

	suite.add("TextEncoder (short ascii str)", function () {
		// TextEncoder (short ascii str)
		encode(longAscii);
	});

	suite.add("charCodeAt (short ascii str)", function () {
		// charCodeAt (short ascii str)
		toBytes(longAscii);
	});

	suite.on("cycle", function (evt) {
		console.log(" - " + evt.target);
	});

	suite.on("complete", function (evt) {
		console.log(new Array(30).join("-"));

		var results = evt.currentTarget.sort(function (a, b) {
			return b.hz - a.hz;
		});

		results.forEach(function (item) {
			console.log((idx + 1) + ". " + item);
		});
	});

	console.log("TextEncoder vs charCodeAt");
	console.log(new Array(30).join("-"));
	suite.run();
});
	<!DOCTYPE html>
	<html>
	<head>
	<meta charset="utf-8"/>
	<title>TextEncoder vs charCodeAt</title>
	<script src="https://cdnjs.cloudflare.com/ajax/libs/benchmark/1.0.0/benchmark.min.js"></script>
	<script src="./suite.js"></script>
	</head>
	<body>
	<h1>Open the console to view the results</h1>
	<h2><code>cmd + alt + j</code> or <code>ctrl + alt + j</code></h2>
	</body>
	</html>
	"use strict";

	(function (factory) {
	if (typeof Benchmark !== "undefined") {
	factory(Benchmark);
	} else {
	factory(require("benchmark"));
	}
	})(function (Benchmark) {
	var suite = new Benchmark.Suite;

	Benchmark.prototype.setup = function () {
	const shortAscii = 'test'.repeat(100);
	const longAscii = 'test'.repeat(5000);

	const encoder = new TextEncoder();
	function encode(str) {
	return encoder.encode(str);
	}

	const CONTINUE = 0b1000_0000;
	const TWO_BYTE = 0b1100_0000;
	const THREE_BYTE = 1110_0000;
	const FOUR_BYTE = 0b1111_0000;
	const MASK = 0b11_1111;
	function toBytes(str) {
	const bytes = new Uint8Array(length(str));

	let index = 0;
	for (let i = 0; i < str.length; i++) {
	const c = str.charCodeAt(0);
	if (c < 0x80) {
	bytes[index++] = c;
	continue;
	}

	if (c < 0x800) {
	bytes[index++] = (c >> 6) \| TWO_BYTE;
	bytes[index++] = (c & MASK) \| CONTINUE;
	}

	if (
	(c & 0xfc00) == 0xd800 &&
	i + 1 < str.length &&
	(str.charCodeAt(i + 1) & 0xfc00) == 0xdc00
	) {
	// Surrogate Pair
	c = 0x10000 + ((c & 0x03ff) << 10) + (str.charCodeAt(++i) & 0x03ff);
	out[index++] = (c >> 18) \| FOUR_BYTE;
	out[index++] = ((c >> 12) & MASK) \| CONTINUE;
	out[index++] = ((c >> 6) & MASK) \| CONTINUE;
	out[index++] = (c & MASK) \| CONTINUE;
	continue;
	}

	out[index++] = (c >> 12) \| THREE_BYTE;
	out[index++] = ((c >> 6) & MASK) \| CONTINUE;
	out[index++] = (c & MASK) \| CONTINUE;
	continue;
	}
	}

	function length(str) {
	let length = 0;
	for (let i = 0; i < str.length; i++) {
	const c = str.charCodeAt(0);
	if (c < 0x80) {
	length += 1;
	continue;
	}

	if (c < 0x800) {
	length += 2;
	continue;
	}
	if (
	(c & 0xfc00) == 0xd800 &&
	i + 1 < str.length &&
	(str.charCodeAt(i + 1) & 0xfc00) == 0xdc00
	) {
	length += 4;
	continue;
	}

	length += 3;
	}
	return length;
	}
	};


	suite.add("TextEncoder (short ascii str)", function () {
	// TextEncoder (short ascii str)
	encode(shortAscii);
	});

	suite.add("charCodeAt (short ascii str)", function () {
	// charCodeAt (short ascii str)
	toBytes(shortAscii);
	});

	suite.add("TextEncoder (short ascii str)", function () {
	// TextEncoder (short ascii str)
	encode(longAscii);
	});

	suite.add("charCodeAt (short ascii str)", function () {
	// charCodeAt (short ascii str)
	toBytes(longAscii);
	});

	suite.on("cycle", function (evt) {
	console.log(" - " + evt.target);
	});

	suite.on("complete", function (evt) {
	console.log(new Array(30).join("-"));

	var results = evt.currentTarget.sort(function (a, b) {
	return b.hz - a.hz;
	});

	results.forEach(function (item) {
	console.log((idx + 1) + ". " + item);
	});
	});

	console.log("TextEncoder vs charCodeAt");
	console.log(new Array(30).join("-"));
	suite.run();
	});