50 lines
1.5 KiB
JavaScript
50 lines
1.5 KiB
JavaScript
import { ERROR_PACKET, PACKET_TYPES_REVERSE } from "./commons.js";
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import { decode } from "./contrib/base64-arraybuffer.js";
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const withNativeArrayBuffer = typeof ArrayBuffer === "function";
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const decodePacket = (encodedPacket, binaryType) => {
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if (typeof encodedPacket !== "string") {
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return {
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type: "message",
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data: mapBinary(encodedPacket, binaryType)
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};
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}
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const type = encodedPacket.charAt(0);
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if (type === "b") {
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return {
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type: "message",
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data: decodeBase64Packet(encodedPacket.substring(1), binaryType)
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};
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}
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const packetType = PACKET_TYPES_REVERSE[type];
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if (!packetType) {
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return ERROR_PACKET;
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}
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return encodedPacket.length > 1
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? {
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type: PACKET_TYPES_REVERSE[type],
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data: encodedPacket.substring(1)
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}
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: {
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type: PACKET_TYPES_REVERSE[type]
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};
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};
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const decodeBase64Packet = (data, binaryType) => {
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if (withNativeArrayBuffer) {
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const decoded = decode(data);
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return mapBinary(decoded, binaryType);
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}
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else {
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return { base64: true, data }; // fallback for old browsers
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}
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};
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const mapBinary = (data, binaryType) => {
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switch (binaryType) {
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case "blob":
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return data instanceof ArrayBuffer ? new Blob([data]) : data;
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case "arraybuffer":
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default:
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return data; // assuming the data is already an ArrayBuffer
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}
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};
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export default decodePacket;
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