52 lines
1.3 KiB
JavaScript
52 lines
1.3 KiB
JavaScript
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const { PACKET_TYPES_REVERSE, ERROR_PACKET } = require("./commons");
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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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const buffer = Buffer.from(encodedPacket.substring(1), "base64");
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return {
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type: "message",
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data: mapBinary(buffer, binaryType)
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};
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}
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if (!PACKET_TYPES_REVERSE[type]) {
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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 mapBinary = (data, binaryType) => {
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const isBuffer = Buffer.isBuffer(data);
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switch (binaryType) {
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case "arraybuffer":
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return isBuffer ? toArrayBuffer(data) : data;
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case "nodebuffer":
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default:
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return data; // assuming the data is already a Buffer
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}
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};
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const toArrayBuffer = buffer => {
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const arrayBuffer = new ArrayBuffer(buffer.length);
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const view = new Uint8Array(arrayBuffer);
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for (let i = 0; i < buffer.length; i++) {
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view[i] = buffer[i];
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}
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return arrayBuffer;
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};
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module.exports = decodePacket;
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