130 lines
5 KiB
JavaScript
130 lines
5 KiB
JavaScript
"use strict";
|
|
Object.defineProperty(exports, "__esModule", { value: true });
|
|
const util_1 = require("./util");
|
|
const utils_1 = require("../utils");
|
|
const redis_1 = require("../redis");
|
|
const debug = utils_1.Debug("cluster:subscriber");
|
|
class ClusterSubscriber {
|
|
constructor(connectionPool, emitter) {
|
|
this.connectionPool = connectionPool;
|
|
this.emitter = emitter;
|
|
this.started = false;
|
|
this.subscriber = null;
|
|
this.connectionPool.on("-node", (_, key) => {
|
|
if (!this.started || !this.subscriber) {
|
|
return;
|
|
}
|
|
if (util_1.getNodeKey(this.subscriber.options) === key) {
|
|
debug("subscriber has left, selecting a new one...");
|
|
this.selectSubscriber();
|
|
}
|
|
});
|
|
this.connectionPool.on("+node", () => {
|
|
if (!this.started || this.subscriber) {
|
|
return;
|
|
}
|
|
debug("a new node is discovered and there is no subscriber, selecting a new one...");
|
|
this.selectSubscriber();
|
|
});
|
|
}
|
|
getInstance() {
|
|
return this.subscriber;
|
|
}
|
|
selectSubscriber() {
|
|
const lastActiveSubscriber = this.lastActiveSubscriber;
|
|
// Disconnect the previous subscriber even if there
|
|
// will not be a new one.
|
|
if (lastActiveSubscriber) {
|
|
lastActiveSubscriber.disconnect();
|
|
}
|
|
if (this.subscriber) {
|
|
this.subscriber.disconnect();
|
|
}
|
|
const sampleNode = utils_1.sample(this.connectionPool.getNodes());
|
|
if (!sampleNode) {
|
|
debug("selecting subscriber failed since there is no node discovered in the cluster yet");
|
|
this.subscriber = null;
|
|
return;
|
|
}
|
|
const { options } = sampleNode;
|
|
debug("selected a subscriber %s:%s", options.host, options.port);
|
|
/*
|
|
* Create a specialized Redis connection for the subscription.
|
|
* Note that auto reconnection is enabled here.
|
|
*
|
|
* `enableReadyCheck` is also enabled because although subscription is allowed
|
|
* while redis is loading data from the disk, we can check if the password
|
|
* provided for the subscriber is correct, and if not, the current subscriber
|
|
* will be disconnected and a new subscriber will be selected.
|
|
*/
|
|
this.subscriber = new redis_1.default({
|
|
port: options.port,
|
|
host: options.host,
|
|
username: options.username,
|
|
password: options.password,
|
|
enableReadyCheck: true,
|
|
connectionName: util_1.getConnectionName("subscriber", options.connectionName),
|
|
lazyConnect: true,
|
|
tls: options.tls,
|
|
});
|
|
// Ignore the errors since they're handled in the connection pool.
|
|
this.subscriber.on("error", utils_1.noop);
|
|
// Re-subscribe previous channels
|
|
const previousChannels = { subscribe: [], psubscribe: [] };
|
|
if (lastActiveSubscriber) {
|
|
const condition = lastActiveSubscriber.condition || lastActiveSubscriber.prevCondition;
|
|
if (condition && condition.subscriber) {
|
|
previousChannels.subscribe = condition.subscriber.channels("subscribe");
|
|
previousChannels.psubscribe = condition.subscriber.channels("psubscribe");
|
|
}
|
|
}
|
|
if (previousChannels.subscribe.length ||
|
|
previousChannels.psubscribe.length) {
|
|
let pending = 0;
|
|
for (const type of ["subscribe", "psubscribe"]) {
|
|
const channels = previousChannels[type];
|
|
if (channels.length) {
|
|
pending += 1;
|
|
debug("%s %d channels", type, channels.length);
|
|
this.subscriber[type](channels)
|
|
.then(() => {
|
|
if (!--pending) {
|
|
this.lastActiveSubscriber = this.subscriber;
|
|
}
|
|
})
|
|
.catch(() => {
|
|
// TODO: should probably disconnect the subscriber and try again.
|
|
debug("failed to %s %d channels", type, channels.length);
|
|
});
|
|
}
|
|
}
|
|
}
|
|
else {
|
|
this.lastActiveSubscriber = this.subscriber;
|
|
}
|
|
for (const event of ["message", "messageBuffer"]) {
|
|
this.subscriber.on(event, (arg1, arg2) => {
|
|
this.emitter.emit(event, arg1, arg2);
|
|
});
|
|
}
|
|
for (const event of ["pmessage", "pmessageBuffer"]) {
|
|
this.subscriber.on(event, (arg1, arg2, arg3) => {
|
|
this.emitter.emit(event, arg1, arg2, arg3);
|
|
});
|
|
}
|
|
}
|
|
start() {
|
|
this.started = true;
|
|
this.selectSubscriber();
|
|
debug("started");
|
|
}
|
|
stop() {
|
|
this.started = false;
|
|
if (this.subscriber) {
|
|
this.subscriber.disconnect();
|
|
this.subscriber = null;
|
|
}
|
|
debug("stopped");
|
|
}
|
|
}
|
|
exports.default = ClusterSubscriber;
|