mastercache/src/cache/stack/cache-stack.ts

Multi-tier cache module for Node.js. Redis, Upstash, CloudfareKV, File, in-memory and others drivers

import lodash from 'lodash';

import { Bus } from '../../bus/bus';
import { LocalCache } from '../facades/local-cache';
import { RemoteCache } from '../facades/remote-cache';
import { BaseDriver } from '../../drivers/base-driver';
import { JsonSerializer } from '../../serializers/json';
import type { MasterCacheOptions } from '../../mastercache-options';
import { CacheEntryOptions } from '../cache-entry/cache-entry-options';
import type {
  BusDriver,
  BusOptions,
  CacheEvent,
  CacheStackDrivers,
  CacheBusMessage,
  Logger,
} from '../../types/main';

export class CacheStack extends BaseDriver {
  #serializer = new JsonSerializer();

  l1?: LocalCache;
  l2?: RemoteCache;
  bus?: Bus;
  defaultOptions: CacheEntryOptions;
  logger: Logger;
  #busDriver?: BusDriver;
  #busOptions?: BusOptions;
  #namespaceCache: Map<string, CacheStack> = new Map();

  constructor(
    public name: string,
    public options: MasterCacheOptions,
    drivers: CacheStackDrivers,
    bus?: Bus,
  ) {
    super(options);
    this.logger = options.logger.child({ cache: this.name });

    if (drivers.l1Driver) this.l1 = new LocalCache(drivers.l1Driver, this.logger);
    if (drivers.l2Driver) this.l2 = new RemoteCache(drivers.l2Driver, this.logger);

    this.bus = bus ? bus : this.#createBus(drivers.busDriver, drivers.busOptions);
    if (this.l1) this.bus?.manageCache(this.prefix, this.l1);

    this.defaultOptions = new CacheEntryOptions(options);
  }

  get emitter() {
    return this.options.emitter;
  }

  #createBus(busDriver?: BusDriver, busOptions?: BusOptions) {
    if (!busDriver) return;

    this.#busDriver = busDriver;
    this.#busOptions = lodash.merge(
      { retryQueue: { enabled: true, maxSize: undefined } },
      busOptions,
    );
    const newBus = new Bus(this.name, this.#busDriver, this.logger, this.emitter, this.#busOptions);

    return newBus;
  }

  namespace(namespace: string): CacheStack {
    if (!this.#namespaceCache.has(namespace)) {
      this.#namespaceCache.set(
        namespace,
        new CacheStack(
          this.name,
          this.options.cloneWith({ prefix: this.createNamespacePrefix(namespace) }),
          {
            l1Driver: this.l1?.namespace(namespace),
            l2Driver: this.l2?.namespace(namespace),
          },
          this.bus,
        ),
      );
    }

    return <CacheStack>this.#namespaceCache.get(namespace);
  }

  /**
   * Publish a message to the bus channel
   *
   * @returns true if the message was published, false if not
   * and undefined if a bus is not part of the stack
   */
  async publish(message: CacheBusMessage): Promise<boolean | undefined> {
    return this.bus?.publish({ ...message, namespace: this.prefix });
  }

  emit(event: CacheEvent) {
    return this.emitter.emit(event.name, event.toJSON());
  }

  serialize(value: any) {
    return this.#serializer.serialize(value);
  }

  deserialize(value: string) {
    return this.#serializer.deserialize(value);
  }
}