function stringToArrayBuffer(str) {
var bytes = new Array();
var len,c;
len = str.length;
for(var i = 0; i < len; i++){
c = str.charCodeAt(i);
if(c >= 0x010000 && c <= 0x10FFFF){
bytes.push(((c >> 18) & 0x07) | 0xF0);
bytes.push(((c >> 12) & 0x3F) | 0x80);
bytes.push(((c >> 6) & 0x3F) | 0x80);
bytes.push((c & 0x3F) | 0x80);
}else if(c >= 0x000800 && c <= 0x00FFFF){
bytes.push(((c >> 12) & 0x0F) | 0xE0);
bytes.push(((c >> 6) & 0x3F) | 0x80);
bytes.push((c & 0x3F) | 0x80);
}else if(c >= 0x000080 && c <= 0x0007FF){
bytes.push(((c >> 6) & 0x1F) | 0xC0);
bytes.push((c & 0x3F) | 0x80);
}else{
bytes.push(c & 0xFF);
}
}
var array = new Int8Array(bytes.length);
for(var i in bytes){
array[i] =bytes[i];
}
return array.buffer;
}
function arrayBufferToString(arr){
if(typeof arr === 'string') {
return arr;
}
var dataview=new DataView(arr.data);
var ints=new Uint8Array(arr.data.byteLength);
for(var i=0;i<ints.length;i++){
ints[i]=dataview.getUint8(i);
}
arr=ints;
var str = '',
_arr = arr;
for(var i = 0; i < _arr.length; i++) {
var one = _arr[i].toString(2),
v = one.match(/^1+?(?=0)/);
if(v && one.length == 8) {
var bytesLength = v[0].length;
var store = _arr[i].toString(2).slice(7 - bytesLength);
for(var st = 1; st < bytesLength; st++) {
store += _arr[st + i].toString(2).slice(2);
}
str += String.fromCharCode(parseInt(store, 2));
i += bytesLength - 1;
} else {
str += String.fromCharCode(_arr[i]);
}
}
return str;
}
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