1234567891011121314151617181920212223242526272829303132333435363738394041424344454647484950515253545556575859606162636465666768697071727374757677787980818283 |
- import { isBinary } from "./is-binary.js";
- /**
- * Replaces every Buffer | ArrayBuffer | Blob | File in packet with a numbered placeholder.
- *
- * @param {Object} packet - socket.io event packet
- * @return {Object} with deconstructed packet and list of buffers
- * @public
- */
- export function deconstructPacket(packet) {
- const buffers = [];
- const packetData = packet.data;
- const pack = packet;
- pack.data = _deconstructPacket(packetData, buffers);
- pack.attachments = buffers.length; // number of binary 'attachments'
- return { packet: pack, buffers: buffers };
- }
- function _deconstructPacket(data, buffers) {
- if (!data)
- return data;
- if (isBinary(data)) {
- const placeholder = { _placeholder: true, num: buffers.length };
- buffers.push(data);
- return placeholder;
- }
- else if (Array.isArray(data)) {
- const newData = new Array(data.length);
- for (let i = 0; i < data.length; i++) {
- newData[i] = _deconstructPacket(data[i], buffers);
- }
- return newData;
- }
- else if (typeof data === "object" && !(data instanceof Date)) {
- const newData = {};
- for (const key in data) {
- if (Object.prototype.hasOwnProperty.call(data, key)) {
- newData[key] = _deconstructPacket(data[key], buffers);
- }
- }
- return newData;
- }
- return data;
- }
- /**
- * Reconstructs a binary packet from its placeholder packet and buffers
- *
- * @param {Object} packet - event packet with placeholders
- * @param {Array} buffers - binary buffers to put in placeholder positions
- * @return {Object} reconstructed packet
- * @public
- */
- export function reconstructPacket(packet, buffers) {
- packet.data = _reconstructPacket(packet.data, buffers);
- delete packet.attachments; // no longer useful
- return packet;
- }
- function _reconstructPacket(data, buffers) {
- if (!data)
- return data;
- if (data && data._placeholder === true) {
- const isIndexValid = typeof data.num === "number" &&
- data.num >= 0 &&
- data.num < buffers.length;
- if (isIndexValid) {
- return buffers[data.num]; // appropriate buffer (should be natural order anyway)
- }
- else {
- throw new Error("illegal attachments");
- }
- }
- else if (Array.isArray(data)) {
- for (let i = 0; i < data.length; i++) {
- data[i] = _reconstructPacket(data[i], buffers);
- }
- }
- else if (typeof data === "object") {
- for (const key in data) {
- if (Object.prototype.hasOwnProperty.call(data, key)) {
- data[key] = _reconstructPacket(data[key], buffers);
- }
- }
- }
- return data;
- }
|