56 lines
1.7 KiB
JavaScript
56 lines
1.7 KiB
JavaScript
|
import { ERROR_PACKET, PACKET_TYPES_REVERSE, } from "./commons.js";
|
||
|
|
export const decodePacket = (encodedPacket, binaryType) => {
|
||
|
|
if (typeof encodedPacket !== "string") {
|
||
|
|
return {
|
||
|
|
type: "message",
|
||
|
|
data: mapBinary(encodedPacket, binaryType),
|
||
|
|
};
|
||
|
|
}
|
||
|
|
const type = encodedPacket.charAt(0);
|
||
|
|
if (type === "b") {
|
||
|
|
const buffer = Buffer.from(encodedPacket.substring(1), "base64");
|
||
|
|
return {
|
||
|
|
type: "message",
|
||
|
|
data: mapBinary(buffer, binaryType),
|
||
|
|
};
|
||
|
|
}
|
||
|
|
if (!PACKET_TYPES_REVERSE[type]) {
|
||
|
|
return ERROR_PACKET;
|
||
|
|
}
|
||
|
|
return encodedPacket.length > 1
|
||
|
|
? {
|
||
|
|
type: PACKET_TYPES_REVERSE[type],
|
||
|
|
data: encodedPacket.substring(1),
|
||
|
|
}
|
||
|
|
: {
|
||
|
|
type: PACKET_TYPES_REVERSE[type],
|
||
|
|
};
|
||
|
|
};
|
||
|
|
const mapBinary = (data, binaryType) => {
|
||
|
|
switch (binaryType) {
|
||
|
|
case "arraybuffer":
|
||
|
|
if (data instanceof ArrayBuffer) {
|
||
|
|
// from WebSocket & binaryType "arraybuffer"
|
||
|
|
return data;
|
||
|
|
}
|
||
|
|
else if (Buffer.isBuffer(data)) {
|
||
|
|
// from HTTP long-polling
|
||
|
|
return data.buffer.slice(data.byteOffset, data.byteOffset + data.byteLength);
|
||
|
|
}
|
||
|
|
else {
|
||
|
|
// from WebTransport (Uint8Array)
|
||
|
|
return data.buffer;
|
||
|
|
}
|
||
|
|
case "nodebuffer":
|
||
|
|
default:
|
||
|
|
if (Buffer.isBuffer(data)) {
|
||
|
|
// from HTTP long-polling or WebSocket & binaryType "nodebuffer" (default)
|
||
|
|
return data;
|
||
|
|
}
|
||
|
|
else {
|
||
|
|
// from WebTransport (Uint8Array)
|
||
|
|
return Buffer.from(data);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
};
|