155 lines
7.1 KiB
JavaScript
155 lines
7.1 KiB
JavaScript
"use strict";
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Object.defineProperty(exports, "__esModule", { value: true });
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class Serializer {
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constructor(allowedMetadataKeys) {
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this.HEADER_LENGTH = 1;
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this.USER_BROADCAST_PUSH_META_LENGTH = 6;
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this.KINDS = { userBroadcastPush: 3, userBroadcast: 4 };
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this.BINARY_ENCODING = 0;
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this.JSON_ENCODING = 1;
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this.BROADCAST_EVENT = 'broadcast';
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this.allowedMetadataKeys = [];
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this.allowedMetadataKeys = allowedMetadataKeys !== null && allowedMetadataKeys !== void 0 ? allowedMetadataKeys : [];
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}
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encode(msg, callback) {
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if (msg.event === this.BROADCAST_EVENT &&
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!(msg.payload instanceof ArrayBuffer) &&
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typeof msg.payload.event === 'string') {
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return callback(this._binaryEncodeUserBroadcastPush(msg));
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}
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let payload = [msg.join_ref, msg.ref, msg.topic, msg.event, msg.payload];
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return callback(JSON.stringify(payload));
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}
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_binaryEncodeUserBroadcastPush(message) {
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var _a;
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if (this._isArrayBuffer((_a = message.payload) === null || _a === void 0 ? void 0 : _a.payload)) {
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return this._encodeBinaryUserBroadcastPush(message);
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}
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else {
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return this._encodeJsonUserBroadcastPush(message);
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}
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}
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_encodeBinaryUserBroadcastPush(message) {
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var _a, _b;
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const userPayload = (_b = (_a = message.payload) === null || _a === void 0 ? void 0 : _a.payload) !== null && _b !== void 0 ? _b : new ArrayBuffer(0);
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return this._encodeUserBroadcastPush(message, this.BINARY_ENCODING, userPayload);
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}
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_encodeJsonUserBroadcastPush(message) {
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var _a, _b;
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const userPayload = (_b = (_a = message.payload) === null || _a === void 0 ? void 0 : _a.payload) !== null && _b !== void 0 ? _b : {};
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const encoder = new TextEncoder();
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const encodedUserPayload = encoder.encode(JSON.stringify(userPayload)).buffer;
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return this._encodeUserBroadcastPush(message, this.JSON_ENCODING, encodedUserPayload);
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}
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_encodeUserBroadcastPush(message, encodingType, encodedPayload) {
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var _a, _b;
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const topic = message.topic;
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const ref = (_a = message.ref) !== null && _a !== void 0 ? _a : '';
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const joinRef = (_b = message.join_ref) !== null && _b !== void 0 ? _b : '';
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const userEvent = message.payload.event;
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// Filter metadata based on allowed keys
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const rest = this.allowedMetadataKeys
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? this._pick(message.payload, this.allowedMetadataKeys)
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: {};
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const metadata = Object.keys(rest).length === 0 ? '' : JSON.stringify(rest);
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// Validate lengths don't exceed uint8 max value (255)
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if (joinRef.length > 255) {
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throw new Error(`joinRef length ${joinRef.length} exceeds maximum of 255`);
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}
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if (ref.length > 255) {
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throw new Error(`ref length ${ref.length} exceeds maximum of 255`);
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}
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if (topic.length > 255) {
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throw new Error(`topic length ${topic.length} exceeds maximum of 255`);
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}
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if (userEvent.length > 255) {
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throw new Error(`userEvent length ${userEvent.length} exceeds maximum of 255`);
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}
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if (metadata.length > 255) {
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throw new Error(`metadata length ${metadata.length} exceeds maximum of 255`);
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}
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const metaLength = this.USER_BROADCAST_PUSH_META_LENGTH +
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joinRef.length +
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ref.length +
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topic.length +
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userEvent.length +
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metadata.length;
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const header = new ArrayBuffer(this.HEADER_LENGTH + metaLength);
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let view = new DataView(header);
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let offset = 0;
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view.setUint8(offset++, this.KINDS.userBroadcastPush); // kind
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view.setUint8(offset++, joinRef.length);
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view.setUint8(offset++, ref.length);
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view.setUint8(offset++, topic.length);
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view.setUint8(offset++, userEvent.length);
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view.setUint8(offset++, metadata.length);
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view.setUint8(offset++, encodingType);
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Array.from(joinRef, (char) => view.setUint8(offset++, char.charCodeAt(0)));
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Array.from(ref, (char) => view.setUint8(offset++, char.charCodeAt(0)));
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Array.from(topic, (char) => view.setUint8(offset++, char.charCodeAt(0)));
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Array.from(userEvent, (char) => view.setUint8(offset++, char.charCodeAt(0)));
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Array.from(metadata, (char) => view.setUint8(offset++, char.charCodeAt(0)));
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var combined = new Uint8Array(header.byteLength + encodedPayload.byteLength);
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combined.set(new Uint8Array(header), 0);
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combined.set(new Uint8Array(encodedPayload), header.byteLength);
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return combined.buffer;
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}
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decode(rawPayload, callback) {
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if (this._isArrayBuffer(rawPayload)) {
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let result = this._binaryDecode(rawPayload);
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return callback(result);
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}
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if (typeof rawPayload === 'string') {
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const jsonPayload = JSON.parse(rawPayload);
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const [join_ref, ref, topic, event, payload] = jsonPayload;
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return callback({ join_ref, ref, topic, event, payload });
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}
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return callback({});
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}
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_binaryDecode(buffer) {
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const view = new DataView(buffer);
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const kind = view.getUint8(0);
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const decoder = new TextDecoder();
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switch (kind) {
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case this.KINDS.userBroadcast:
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return this._decodeUserBroadcast(buffer, view, decoder);
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}
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}
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_decodeUserBroadcast(buffer, view, decoder) {
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const topicSize = view.getUint8(1);
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const userEventSize = view.getUint8(2);
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const metadataSize = view.getUint8(3);
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const payloadEncoding = view.getUint8(4);
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let offset = this.HEADER_LENGTH + 4;
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const topic = decoder.decode(buffer.slice(offset, offset + topicSize));
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offset = offset + topicSize;
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const userEvent = decoder.decode(buffer.slice(offset, offset + userEventSize));
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offset = offset + userEventSize;
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const metadata = decoder.decode(buffer.slice(offset, offset + metadataSize));
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offset = offset + metadataSize;
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const payload = buffer.slice(offset, buffer.byteLength);
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const parsedPayload = payloadEncoding === this.JSON_ENCODING ? JSON.parse(decoder.decode(payload)) : payload;
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const data = {
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type: this.BROADCAST_EVENT,
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event: userEvent,
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payload: parsedPayload,
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};
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// Metadata is optional and always JSON encoded
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if (metadataSize > 0) {
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data['meta'] = JSON.parse(metadata);
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}
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return { join_ref: null, ref: null, topic: topic, event: this.BROADCAST_EVENT, payload: data };
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}
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_isArrayBuffer(buffer) {
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var _a;
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return buffer instanceof ArrayBuffer || ((_a = buffer === null || buffer === void 0 ? void 0 : buffer.constructor) === null || _a === void 0 ? void 0 : _a.name) === 'ArrayBuffer';
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}
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_pick(obj, keys) {
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if (!obj || typeof obj !== 'object') {
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return {};
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}
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return Object.fromEntries(Object.entries(obj).filter(([key]) => keys.includes(key)));
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}
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}
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exports.default = Serializer;
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//# sourceMappingURL=serializer.js.map
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