fast-clear.html

<script>
[
	Uint8Array,
	Uint8ClampedArray,
	Uint16Array,
	Uint32Array,
	Int8Array,
	Int16Array,
	Int32Array,
	Float32Array,
	Float64Array
].forEach((type) => {
	type.prototype.clear = function () {
		// Float64Array is faster but since the array may not be a multiple of 8 bytes, we use Int8Array to set the remaining bytes
		const fastView = new Float64Array(this.buffer, 0, (this.buffer.byteLength / Float64Array.BYTES_PER_ELEMENT)|0);
		const byteView = new Int8Array(this.buffer, fastView.byteLength, this.buffer.byteLength % Float64Array.BYTES_PER_ELEMENT);

		const length1 = fastView.length;
		const length2 = byteView.length;

		for (let i = 0; i < length1; i++) {
			fastView[i] = 0;
		}

		for (let i = 0; i < length2; i++) {
			byteView[i] = 0;
		}

		return this;
	};
});


let arr = new Uint8Array(1024 * 1024 * 256);

for (let i = 0; i < 10; i++) {
    let start = performance.now();
    arr.clear();
    let end = performance.now();
    console.log('time1', end - start);


    let start2 = performance.now();
    arr.fill(0);
    let end2 = performance.now();
    console.log('time2', end2 - start2);
}
</script>