encodePacket.js
860 Bytes
import { PACKET_TYPES } from "./commons.js";
const encodePacket = ({ type, data }, supportsBinary, callback) => {
if (data instanceof ArrayBuffer || ArrayBuffer.isView(data)) {
const buffer = toBuffer(data);
return callback(encodeBuffer(buffer, supportsBinary));
}
// plain string
return callback(PACKET_TYPES[type] + (data || ""));
};
const toBuffer = data => {
if (Buffer.isBuffer(data)) {
return data;
}
else if (data instanceof ArrayBuffer) {
return Buffer.from(data);
}
else {
return Buffer.from(data.buffer, data.byteOffset, data.byteLength);
}
};
// only 'message' packets can contain binary, so the type prefix is not needed
const encodeBuffer = (data, supportsBinary) => {
return supportsBinary ? data : "b" + data.toString("base64");
};
export default encodePacket;