| 1 | /* eslint-disable ts/no-explicit-any */ |
| 2 | import { Injectable, Logger, OnModuleInit } from '@nestjs/common' |
| 3 | import { Redis } from 'ioredis' |
| 4 | |
| 5 | @Injectable() |
| 6 | export class RedisPubSubService implements OnModuleInit { |
| 7 | private readonly logger = new Logger(RedisPubSubService.name) |
| 8 | private readonly listeners = new Map<string, Set<(data: any) => void>>() |
| 9 | private readonly onceListeners = new Map<string, Set<(data: any) => void>>() |
| 10 | private readonly subscribedChannels = new Set<string>() |
| 11 | |
| 12 | private readonly messageHandler = (channel: string, message: string) => { |
| 13 | try { |
| 14 | const data = JSON.parse(message) |
| 15 | this.dispatchMessage(channel, data) |
| 16 | } |
| 17 | catch (error) { |
| 18 | this.logger.error(`Failed to parse message on channel ${channel}: ${error}`) |
| 19 | } |
| 20 | } |
| 21 | |
| 22 | constructor( |
| 23 | private readonly subscriber: Redis, |
| 24 | private readonly publisher: Redis, |
| 25 | ) { } |
| 26 | |
| 27 | async onModuleInit() { |
| 28 | this.subscriber.on('message', this.messageHandler) |
| 29 | this.logger.log('Redis Pub/Sub EventEmitter initialized') |
| 30 | } |
| 31 | |
| 32 | on<T = any>(channel: string, listener: (data: T) => void): this { |
| 33 | if (!this.listeners.has(channel)) { |
| 34 | this.listeners.set(channel, new Set()) |
| 35 | } |
| 36 | this.listeners.get(channel)!.add(listener) |
| 37 | |
| 38 | if (!this.subscribedChannels.has(channel)) { |
| 39 | this.subscribeChannel(channel) |
| 40 | } |
| 41 | |
| 42 | return this |
| 43 | } |
| 44 | |
| 45 | off<T = any>(channel: string, listener: (data: T) => void): this { |
| 46 | const channelListeners = this.listeners.get(channel) |
| 47 | if (channelListeners) { |
| 48 | channelListeners.delete(listener) |
| 49 | if (channelListeners.size === 0) { |
| 50 | this.listeners.delete(channel) |
| 51 | } |
| 52 | } |
| 53 | |
| 54 | const channelOnceListeners = this.onceListeners.get(channel) |
| 55 | if (channelOnceListeners) { |
| 56 | channelOnceListeners.delete(listener) |
| 57 | if (channelOnceListeners.size === 0) { |
| 58 | this.onceListeners.delete(channel) |
| 59 | } |
| 60 | } |
| 61 | |
| 62 | if (!this.listeners.has(channel) && !this.onceListeners.has(channel)) { |
| 63 | this.unsubscribeChannel(channel) |
| 64 | } |
| 65 | |
| 66 | return this |
| 67 | } |
| 68 | |
| 69 | once<T = any>(channel: string, listener: (data: T) => void): this { |
| 70 | const wrappedListener = (data: any) => { |
| 71 | this.off(channel, wrappedListener) |
| 72 | listener(data) |
| 73 | } |
| 74 | |
| 75 | if (!this.onceListeners.has(channel)) { |
| 76 | this.onceListeners.set(channel, new Set()) |
| 77 | } |
| 78 | this.onceListeners.get(channel)!.add(wrappedListener) |
| 79 | |
| 80 | if (!this.subscribedChannels.has(channel)) { |
| 81 | this.subscribeChannel(channel) |
| 82 | } |
| 83 | |
| 84 | return this |
| 85 | } |
| 86 | |
| 87 | async emit(channel: string, data: any): Promise<boolean> { |
| 88 | try { |
| 89 | const res = await this.publisher.publish(channel, JSON.stringify(data)) |
| 90 | return !!res |
| 91 | } |
| 92 | catch (error) { |
| 93 | this.logger.error(`Failed to emit message on channel ${channel}: ${error}`) |
| 94 | return false |
| 95 | } |
| 96 | } |
| 97 | |
| 98 | private dispatchMessage(channel: string, data: any) { |
| 99 | const channelListeners = this.listeners.get(channel) |
| 100 | if (channelListeners) { |
| 101 | for (const listener of channelListeners) { |
| 102 | try { |
| 103 | listener(data) |
| 104 | } |
| 105 | catch (error) { |
| 106 | this.logger.error(`Error in listener for channel ${channel}: ${error}`) |
| 107 | } |
| 108 | } |
| 109 | } |
| 110 | |
| 111 | const channelOnceListeners = this.onceListeners.get(channel) |
| 112 | if (channelOnceListeners) { |
| 113 | const listenersToCall = Array.from(channelOnceListeners) |
| 114 | for (const listener of listenersToCall) { |
| 115 | try { |
| 116 | listener(data) |
| 117 | } |
| 118 | catch (error) { |
| 119 | this.logger.error(`Error in once listener for channel ${channel}: ${error}`) |
| 120 | } |
| 121 | } |
| 122 | } |
| 123 | } |
| 124 | |
| 125 | private subscribeChannel(channel: string) { |
| 126 | if (this.subscribedChannels.has(channel)) { |
| 127 | return |
| 128 | } |
| 129 | |
| 130 | this.subscriber.subscribe(channel).catch((error) => { |
| 131 | this.logger.error(`Failed to subscribe to channel ${channel}: ${error}`) |
| 132 | }) |
| 133 | this.subscribedChannels.add(channel) |
| 134 | this.logger.debug(`Auto-subscribed to channel: ${channel}`) |
| 135 | } |
| 136 | |
| 137 | private unsubscribeChannel(channel: string) { |
| 138 | if (!this.subscribedChannels.has(channel)) { |
| 139 | return |
| 140 | } |
| 141 | |
| 142 | this.subscriber.unsubscribe(channel).catch((error) => { |
| 143 | this.logger.error(`Failed to unsubscribe from channel ${channel}: ${error}`) |
| 144 | }) |
| 145 | this.subscribedChannels.delete(channel) |
| 146 | this.logger.debug(`Auto-unsubscribed from channel: ${channel}`) |
| 147 | } |
| 148 | } |
| 149 |