persistence.md

Persistence Plugin

The Persistence Plugin allows us to persist data to a storage. This plugin uses the Persistence interface to define persistence units.

The default implementation is file-based persistence, but you can create custom persistence plugins to store data in other storage systems.

Usage

To create a Persistence Plugin, you need to implement the Persistence interface and register your persistence units.

Example

Here is an example of an in-memory Persistence Plugin

import { AbstractPlugin, Persistence, PERSISTENCE_PLUGIN, PersistenceUnit } from '@letrun/core';

class InMemoryPersistenceUnit implements PersistenceUnit {
  constructor(private storage: Record<string, any>) {}

  async save(key: string, value: any) {
    this.storage[key] = value;
  }

  async load(key: string) {
    return this.storage[key];
  }

  async remove(key: string) {
    delete this.storage[key];
  }

  async list() {
    return Object.keys(this.storage);
  }
}

export default class InMemoryPersistence extends AbstractPlugin implements Persistence {
  readonly name = 'inmemory-persistence';
  readonly type = PERSISTENCE_PLUGIN;

  private storage: Record<string, any> = {};

  getUnit(name: string): PersistenceUnit {
    if (!this.storage[name]) {
      this.storage[name] = {};
    }
    return new InMemoryPersistenceUnit(this.storage[name]);
  }
}

Registering the Plugin

To register the Persistence Plugin, place it in the plugins directory (or the directory specified in your configuration) and ensure it is loaded by the CLI tool.

Output

The Persistence Plugin allows you to persist data to in-memory storage.

Summary

The Persistence Plugin allows you to extend the CLI tool with custom persistence functionality using the Persistence interface. Implement the Persistence interface, register your persistence units, and place the plugin in the appropriate directory to use it.