|
| 1 | +/** |
| 2 | + * @boringnode/bus |
| 3 | + * |
| 4 | + * @license MIT |
| 5 | + * @copyright BoringNode |
| 6 | + */ |
| 7 | + |
| 8 | +import { Client } from 'pg' |
| 9 | +import { assert } from '@poppinss/utils/assert' |
| 10 | + |
| 11 | +import debug from '../debug.js' |
| 12 | +import { JsonEncoder } from '../encoders/json_encoder.js' |
| 13 | +import type { |
| 14 | + Transport, |
| 15 | + TransportEncoder, |
| 16 | + TransportMessage, |
| 17 | + Serializable, |
| 18 | + SubscribeHandler, |
| 19 | + PostgresTransportConfig, |
| 20 | +} from '../types/main.js' |
| 21 | + |
| 22 | +export function postgres(config: PostgresTransportConfig, encoder?: TransportEncoder) { |
| 23 | + return () => new PostgresTransport(config, encoder) |
| 24 | +} |
| 25 | + |
| 26 | +export class PostgresTransport implements Transport { |
| 27 | + readonly #publisher: Client |
| 28 | + readonly #subscriber: Client |
| 29 | + readonly #encoder: TransportEncoder |
| 30 | + readonly #channelHandlers: Map<string, SubscribeHandler<any>> = new Map() |
| 31 | + #publisherConnected: boolean = false |
| 32 | + #subscriberConnected: boolean = false |
| 33 | + |
| 34 | + #id: string | undefined |
| 35 | + |
| 36 | + constructor(config: PostgresTransportConfig, encoder?: TransportEncoder) |
| 37 | + constructor(config: string, encoder?: TransportEncoder) |
| 38 | + constructor(options: PostgresTransportConfig | string, encoder?: TransportEncoder) { |
| 39 | + this.#encoder = encoder ?? new JsonEncoder() |
| 40 | + |
| 41 | + /** |
| 42 | + * If a connection string is passed, use it for both publisher and subscriber |
| 43 | + */ |
| 44 | + if (typeof options === 'string') { |
| 45 | + this.#publisher = new Client({ connectionString: options }) |
| 46 | + this.#subscriber = new Client({ connectionString: options }) |
| 47 | + return |
| 48 | + } |
| 49 | + |
| 50 | + /** |
| 51 | + * If a config object is passed, create both publisher and subscriber |
| 52 | + */ |
| 53 | + this.#publisher = new Client(options) |
| 54 | + this.#subscriber = new Client(options) |
| 55 | + } |
| 56 | + |
| 57 | + setId(id: string): Transport { |
| 58 | + this.#id = id |
| 59 | + |
| 60 | + return this |
| 61 | + } |
| 62 | + |
| 63 | + async #ensureConnected(): Promise<void> { |
| 64 | + if (!this.#publisherConnected) { |
| 65 | + await this.#publisher.connect() |
| 66 | + this.#publisherConnected = true |
| 67 | + } |
| 68 | + if (!this.#subscriberConnected) { |
| 69 | + await this.#subscriber.connect() |
| 70 | + this.#subscriberConnected = true |
| 71 | + } |
| 72 | + } |
| 73 | + |
| 74 | + async disconnect(): Promise<void> { |
| 75 | + this.#publisherConnected = false |
| 76 | + this.#subscriberConnected = false |
| 77 | + |
| 78 | + const promises: Promise<void>[] = [] |
| 79 | + |
| 80 | + try { |
| 81 | + promises.push(this.#publisher.end()) |
| 82 | + } catch (err) { |
| 83 | + // Ignore errors during disconnect |
| 84 | + } |
| 85 | + |
| 86 | + try { |
| 87 | + promises.push(this.#subscriber.end()) |
| 88 | + } catch (err) { |
| 89 | + // Ignore errors during disconnect |
| 90 | + } |
| 91 | + |
| 92 | + await Promise.allSettled(promises) |
| 93 | + } |
| 94 | + |
| 95 | + async publish(channel: string, message: Serializable): Promise<void> { |
| 96 | + assert(this.#id, 'You must set an id before publishing a message') |
| 97 | + |
| 98 | + await this.#ensureConnected() |
| 99 | + |
| 100 | + const encoded = this.#encoder.encode({ payload: message, busId: this.#id }) |
| 101 | + const payloadString = typeof encoded === 'string' ? encoded : encoded.toString('base64') |
| 102 | + |
| 103 | + // Use pg's built-in escaping methods to safely escape the identifiers and literals |
| 104 | + const escapedChannel = this.#publisher.escapeIdentifier(channel) |
| 105 | + const escapedPayload = this.#publisher.escapeLiteral(payloadString) |
| 106 | + |
| 107 | + // Use NOTIFY to send the message |
| 108 | + await this.#publisher.query(`NOTIFY ${escapedChannel}, ${escapedPayload}`) |
| 109 | + } |
| 110 | + |
| 111 | + async subscribe<T extends Serializable>( |
| 112 | + channel: string, |
| 113 | + handler: SubscribeHandler<T> |
| 114 | + ): Promise<void> { |
| 115 | + await this.#ensureConnected() |
| 116 | + |
| 117 | + // Store the handler for this channel |
| 118 | + this.#channelHandlers.set(channel, handler) |
| 119 | + |
| 120 | + // Set up the notification listener if not already set |
| 121 | + if (this.#subscriber.listenerCount('notification') === 0) { |
| 122 | + this.#subscriber.on('notification', (msg) => { |
| 123 | + if (msg.channel) { |
| 124 | + const channelHandler = this.#channelHandlers.get(msg.channel) |
| 125 | + if (channelHandler && msg.payload) { |
| 126 | + debug('received message for channel "%s"', msg.channel) |
| 127 | + |
| 128 | + try { |
| 129 | + const data = this.#encoder.decode<TransportMessage<T>>(msg.payload) |
| 130 | + |
| 131 | + /** |
| 132 | + * Ignore messages published by this bus instance |
| 133 | + */ |
| 134 | + if (data.busId === this.#id) { |
| 135 | + debug('ignoring message published by the same bus instance') |
| 136 | + return |
| 137 | + } |
| 138 | + |
| 139 | + channelHandler(data.payload) |
| 140 | + } catch (error) { |
| 141 | + debug('error decoding message: %o', error) |
| 142 | + } |
| 143 | + } |
| 144 | + } |
| 145 | + }) |
| 146 | + } |
| 147 | + |
| 148 | + // Subscribe to the channel using LISTEN |
| 149 | + const escapedChannel = this.#subscriber.escapeIdentifier(channel) |
| 150 | + await this.#subscriber.query(`LISTEN ${escapedChannel}`) |
| 151 | + } |
| 152 | + |
| 153 | + onReconnect(callback: () => void): void { |
| 154 | + // PostgreSQL client doesn't have built-in reconnection events |
| 155 | + // We'll listen to connection errors and trigger callback on reconnect |
| 156 | + this.#subscriber.on('error', (err) => { |
| 157 | + debug('subscriber error: %o', err) |
| 158 | + }) |
| 159 | + |
| 160 | + this.#subscriber.on('end', () => { |
| 161 | + debug('subscriber connection ended') |
| 162 | + this.#subscriberConnected = false |
| 163 | + // Attempt to reconnect |
| 164 | + this.#subscriber |
| 165 | + .connect() |
| 166 | + .then(() => { |
| 167 | + this.#subscriberConnected = true |
| 168 | + callback() |
| 169 | + // Re-subscribe to all channels |
| 170 | + for (const channel of this.#channelHandlers.keys()) { |
| 171 | + const escapedChannel = this.#subscriber.escapeIdentifier(channel) |
| 172 | + this.#subscriber.query(`LISTEN ${escapedChannel}`).catch((err) => { |
| 173 | + debug('error re-subscribing to channel %s: %o', channel, err) |
| 174 | + }) |
| 175 | + } |
| 176 | + }) |
| 177 | + .catch((err) => { |
| 178 | + debug('error reconnecting: %o', err) |
| 179 | + }) |
| 180 | + }) |
| 181 | + } |
| 182 | + |
| 183 | + async unsubscribe(channel: string): Promise<void> { |
| 184 | + this.#channelHandlers.delete(channel) |
| 185 | + const escapedChannel = this.#subscriber.escapeIdentifier(channel) |
| 186 | + await this.#subscriber.query(`UNLISTEN ${escapedChannel}`) |
| 187 | + } |
| 188 | +} |
0 commit comments