A polyfill for ArrayBuffer.prototype.transfer that is substantially faster than a naive byte-by-byte transfer implementation.

arraybuffer.transfer.js

if(typeof(ArrayBuffer.prototype.transfer) === "undefined") {
	ArrayBuffer.prototype.transfer = function transfer(old) {
		var dva, dvb, i, mod;
		dva = new DataView(this);
		dvb = new DataView(old);
		mod = this.byteLength%8+1;
		for(i = 0; i <= old.byteLength-mod; i+=8) dva.setFloat64(i, dvb.getFloat64(i));
		mod = this.byteLength%4+1;
		if(i < old.byteLength-mod) {
			dva.setUint32(i, dvb.getUint32(i));
			i += 4;
		}
		mod = this.byteLength%2+1;
		if(i < old.byteLength-mod) {
			dva.setUint16(i, dvb.getUint16(i));
			i += 2;
		}
		if(i < old.byteLength) dva.setUint8(i, dvb.getUint8(i));
	}
}