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@imqueue/pg-cache

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PostgreSQL managed cache on Redis for @imqueue-based service methods

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/*! * I'm Queue Software Project * Copyright (C) 2025 imqueue.com <support@imqueue.com> * * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, either version 3 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program. If not, see <https://www.gnu.org/licenses/>. * * If you want to use this code in a closed source (commercial) project, you can * purchase a proprietary commercial license. Please contact us at * <support@imqueue.com> to get commercial licensing options. */ /** * PostgreSQL-managed cache on Redis for `@imqueue` service methods: results are * memoised, and PostgreSQL itself says when to drop them. * * Decorate the service class with {@link PgCache}, then mark cached methods with * {@link cacheWith} or {@link cacheBy} to declare which tables they depend on. * * @remarks * The point is invalidation that is neither a guessed TTL nor a manual * `del()` call. {@link PgCache} installs a change-notify trigger on each declared * table and subscribes to one LISTEN/NOTIFY channel per table; when a row * changes, the entries tagged with that table are dropped. So an entry lives * exactly as long as the data behind it is unchanged. * * Two things to know. The triggers and the subscription are established in * `start()`, so a service that never starts is never cached. And a * {@link ChannelFilter} given as an array of {@link ChannelOperation} is an * EXCLUSION list — the operations named in it do not invalidate — which reads * the opposite way round from how it looks. * * @example * ```typescript * import { PgCache, cacheWith } from '@imqueue/pg-cache'; * * @PgCache({ * postgres: process.env.DB_URL!, * redis: { host: 'localhost', port: 6379 }, * }) * class UserService extends IMQService { * @cacheWith({ channels: ['users'] }) * public async list(): Promise<User[]> { * return this.db.query('SELECT * FROM users'); * } * } * ``` * * @packageDocumentation */ export * from './src/index.js';