@tdengine/websocket
Version:
The websocket Node.js connector for TDengine. TDengine versions 3.3.2.0 and above are recommended to use this connector.
43 lines (42 loc) • 1.43 kB
JavaScript
;
Object.defineProperty(exports, "__esModule", { value: true });
exports.appendRune = appendRune;
// Numbers fundamental to the encoding.
// the "error" Rune or "Unicode replacement character"
const RuneError = '\uFFFD';
// Maximum valid Unicode code point.
const MaxRune = '\U0010FFFF';
// Code points in the surrogate range are not valid for UTF-8.
const surrogateMin = 0xD800;
const surrogateMax = 0xDFFF;
const tx = 128;
const t2 = 192;
const t3 = 224;
const t4 = 240;
const maskx = 63;
const rune1Max = (1 << 7) - 1;
const rune2Max = (1 << 11) - 1;
const rune3Max = (1 << 16) - 1;
// AppendRune appends the UTF-8 encoding of r to the end of p and
// returns the extended buffer. If the rune is out of range,
// it appends the encoding of RuneError.
function appendRune(r) {
let p = [];
if (r <= rune1Max) {
p.push(r & 0xff);
return Buffer.from(p).toString();
}
if (r <= rune2Max) {
p.push(t2 | ((r >> 6) & 0xff), tx | (r & 0xff) & maskx);
}
else if ((r > MaxRune) || (surrogateMax <= r && r <= surrogateMax)) {
p.push(RuneError);
}
else if (r <= rune3Max) {
p.push(t3 | ((r >> 12) & 0xff), tx | ((r >> 6) & 0xff) & maskx, tx | (r & 0xff) & maskx);
}
else {
p.push(t4 | ((r >> 18) & 0xff), tx | ((r >> 12) & 0xff) & maskx, tx | ((r >> 6) & 0xff) & maskx, tx | (r & 0xff) & maskx);
}
return Buffer.from(p).toString();
}