ioredis
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A robust, performance-focused and full-featured Redis client for Node.js.
87 lines (86 loc) • 2.54 kB
TypeScript
/// <reference types="node" />
import ClusterSubscriber from "./ClusterSubscriber";
import Cluster from "./index";
/**
* Redis differs between "normal" and sharded PubSub. If using the "normal" PubSub feature, exactly one
* ClusterSubscriber exists per cluster instance. This works because the Redis cluster bus forwards m
* messages between shards. However, this has scalability limitations, which is the reason why the sharded
* PubSub feature was added to Redis. With sharded PubSub, each shard is responsible for its own messages.
* Given that, we need at least one ClusterSubscriber per master endpoint/node.
*
* This class leverages the previously exising ClusterSubscriber by adding support for multiple such subscribers
* in alignment to the master nodes of the cluster. The ClusterSubscriber class was extended in a non-breaking way
* to support this feature.
*/
export default class ClusterSubscriberGroup {
private cluster;
private shardedSubscribers;
private clusterSlots;
private subscriberToSlotsIndex;
private channels;
/**
* Register callbacks
*
* @param cluster
*/
constructor(cluster: Cluster);
/**
* Get the responsible subscriber.
*
* Returns null if no subscriber was found
*
* @param slot
*/
getResponsibleSubscriber(slot: number): ClusterSubscriber;
/**
* Adds a channel for which this subscriber group is responsible
*
* @param channels
*/
addChannels(channels: (string | Buffer)[]): number;
/**
* Removes channels for which the subscriber group is responsible by optionally unsubscribing
* @param channels
*/
removeChannels(channels: (string | Buffer)[]): number;
/**
* Disconnect all subscribers
*/
stop(): void;
/**
* Start all not yet started subscribers
*/
start(): void;
/**
* Add a subscriber to the group of subscribers
*
* @param redis
*/
private _addSubscriber;
/**
* Removes a subscriber from the group
* @param redis
*/
private _removeSubscriber;
/**
* Refreshes the subscriber-related slot ranges
*
* Returns false if no refresh was needed
*
* @param cluster
*/
private _refreshSlots;
/**
* Resubscribes to the previous channels
*
* @private
*/
private _resubscribe;
/**
* Deep equality of the cluster slots objects
*
* @param other
* @private
*/
private _slotsAreEqual;
}