98 lines
3.6 KiB
JavaScript
98 lines
3.6 KiB
JavaScript
import {basicAuth, encodeBase64Url, topicShortUrl, topicUrlWs} from "./utils";
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const retryBackoffSeconds = [5, 10, 15, 20, 30, 45];
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class Connection {
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constructor(subscriptionId, baseUrl, topic, user, since, onNotification) {
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this.subscriptionId = subscriptionId;
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this.baseUrl = baseUrl;
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this.topic = topic;
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this.user = user;
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this.since = since;
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this.shortUrl = topicShortUrl(baseUrl, topic);
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this.onNotification = onNotification;
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this.ws = null;
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this.retryCount = 0;
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this.retryTimeout = null;
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}
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start() {
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// Don't fetch old messages; we do that as a poll() when adding a subscription;
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// we don't want to re-trigger the main view re-render potentially hundreds of times.
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const wsUrl = this.wsUrl();
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console.log(`[Connection, ${this.shortUrl}] Opening connection to ${wsUrl}`);
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this.ws = new WebSocket(wsUrl);
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this.ws.onopen = (event) => {
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console.log(`[Connection, ${this.shortUrl}] Connection established`, event);
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this.retryCount = 0;
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}
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this.ws.onmessage = (event) => {
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console.log(`[Connection, ${this.shortUrl}] Message received from server: ${event.data}`);
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try {
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const data = JSON.parse(event.data);
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if (data.event === 'open') {
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return;
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}
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const relevantAndValid =
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data.event === 'message' &&
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'id' in data &&
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'time' in data &&
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'message' in data;
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if (!relevantAndValid) {
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console.log(`[Connection, ${this.shortUrl}] Unexpected message. Ignoring.`);
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return;
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}
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this.since = data.id;
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this.onNotification(this.subscriptionId, data);
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} catch (e) {
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console.log(`[Connection, ${this.shortUrl}] Error handling message: ${e}`);
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}
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};
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this.ws.onclose = (event) => {
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if (event.wasClean) {
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console.log(`[Connection, ${this.shortUrl}] Connection closed cleanly, code=${event.code} reason=${event.reason}`);
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this.ws = null;
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} else {
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const retrySeconds = retryBackoffSeconds[Math.min(this.retryCount, retryBackoffSeconds.length-1)];
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this.retryCount++;
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console.log(`[Connection, ${this.shortUrl}] Connection died, retrying in ${retrySeconds} seconds`);
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this.retryTimeout = setTimeout(() => this.start(), retrySeconds * 1000);
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}
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};
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this.ws.onerror = (event) => {
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console.log(`[Connection, ${this.shortUrl}] Error occurred: ${event}`, event);
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};
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}
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close() {
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console.log(`[Connection, ${this.shortUrl}] Closing connection`);
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const socket = this.ws;
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const retryTimeout = this.retryTimeout;
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if (socket !== null) {
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socket.close();
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}
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if (retryTimeout !== null) {
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clearTimeout(retryTimeout);
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}
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this.retryTimeout = null;
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this.ws = null;
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}
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wsUrl() {
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const params = [];
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if (this.since) {
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params.push(`since=${this.since}`);
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}
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if (this.user) {
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const auth = encodeBase64Url(basicAuth(this.user.username, this.user.password));
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params.push(`auth=${auth}`);
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}
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const wsUrl = topicUrlWs(this.baseUrl, this.topic);
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return (params.length === 0) ? wsUrl : `${wsUrl}?${params.join('&')}`;
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}
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}
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export default Connection;
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