tachyon-expire-cache

TachyonExpireCache is a cache class that allows you to add expiration for data.
It implements the generic IAsyncCache interface from '@luolapeikko/cache-types' and uses the IStorageDriver interface from the "tachyon-drive" to support different storage drivers.

Installation

npm install tachyon-expire-cache
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Validation and serialization type

type CacheMap<Key, Payload> = Map<
  Key,
  { data: Payload; expires: number | undefined }
>;
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Usage

Example with FileStorageDriver and BufferSerializer with zod validation

import { TachyonExpireCache, CacheMap } from "tachyon-expire-cache";
import { IPersistSerializer } from "tachyon-drive";
import { FileStorageDriver } from "tachyon-drive-node-fs";

// type CachePayload<Payload> = {data: Payload; expires: number | undefined};
function cachePayloadSchema<T>(data: z.Schema<T>) {
  return z.object({
    data,
    expires: z.number().optional(),
  });
}

// type CacheMap<Payload, Key = string> = Map<Key, CachePayload<Payload>>
const bufferSerializer: IPersistSerializer<CacheMap<string, string>, Buffer> = {
  serialize: (data: CacheMap<string, string>) =>
    Buffer.from(JSON.stringify(Array.from(data))),
  deserialize: (buffer: Buffer) => new Map(JSON.parse(buffer.toString())),
  validator: (data: CacheMap<string, string>) =>
    z.map(z.string(), cachePayloadSchema(z.string())).safeParse(data).success,
};
const driver = new FileStorageDriver(
  { fileName: "./cache.json", name: "FileStorageDriver" },
  bufferSerializer,
);
const cache = new TachyonExpireCache<string, string>(
  { name: "Some-Cache-Name" },
  driver,
);

await cache.set("key", "value", new Date(Date.now() + 1000));

await cache.get("key"); // 'value'

await cache.has("key"); // true

await cache.delete("key"); // true

await cache.clear();

await cache.size(); // number of items in cache
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