63 lines
1.9 KiB
JavaScript
63 lines
1.9 KiB
JavaScript
|
import { ERROR_PACKET, PACKET_TYPES_REVERSE, } from "./commons.js";
|
||
|
|
import { decode } from "./contrib/base64-arraybuffer.js";
|
||
|
|
const withNativeArrayBuffer = typeof ArrayBuffer === "function";
|
||
|
|
export const decodePacket = (encodedPacket, binaryType) => {
|
||
|
|
if (typeof encodedPacket !== "string") {
|
||
|
|
return {
|
||
|
|
type: "message",
|
||
|
|
data: mapBinary(encodedPacket, binaryType),
|
||
|
|
};
|
||
|
|
}
|
||
|
|
const type = encodedPacket.charAt(0);
|
||
|
|
if (type === "b") {
|
||
|
|
return {
|
||
|
|
type: "message",
|
||
|
|
data: decodeBase64Packet(encodedPacket.substring(1), binaryType),
|
||
|
|
};
|
||
|
|
}
|
||
|
|
const packetType = PACKET_TYPES_REVERSE[type];
|
||
|
|
if (!packetType) {
|
||
|
|
return ERROR_PACKET;
|
||
|
|
}
|
||
|
|
return encodedPacket.length > 1
|
||
|
|
? {
|
||
|
|
type: PACKET_TYPES_REVERSE[type],
|
||
|
|
data: encodedPacket.substring(1),
|
||
|
|
}
|
||
|
|
: {
|
||
|
|
type: PACKET_TYPES_REVERSE[type],
|
||
|
|
};
|
||
|
|
};
|
||
|
|
const decodeBase64Packet = (data, binaryType) => {
|
||
|
|
if (withNativeArrayBuffer) {
|
||
|
|
const decoded = decode(data);
|
||
|
|
return mapBinary(decoded, binaryType);
|
||
|
|
}
|
||
|
|
else {
|
||
|
|
return { base64: true, data }; // fallback for old browsers
|
||
|
|
}
|
||
|
|
};
|
||
|
|
const mapBinary = (data, binaryType) => {
|
||
|
|
switch (binaryType) {
|
||
|
|
case "blob":
|
||
|
|
if (data instanceof Blob) {
|
||
|
|
// from WebSocket + binaryType "blob"
|
||
|
|
return data;
|
||
|
|
}
|
||
|
|
else {
|
||
|
|
// from HTTP long-polling or WebTransport
|
||
|
|
return new Blob([data]);
|
||
|
|
}
|
||
|
|
case "arraybuffer":
|
||
|
|
default:
|
||
|
|
if (data instanceof ArrayBuffer) {
|
||
|
|
// from HTTP long-polling (base64) or WebSocket + binaryType "arraybuffer"
|
||
|
|
return data;
|
||
|
|
}
|
||
|
|
else {
|
||
|
|
// from WebTransport (Uint8Array)
|
||
|
|
return data.buffer;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
};
|