Store: Key and Value Map with TTL

A key-value map with time-to-live (TTL) is a data structure that associates keys with values, similar to a regular map or dictionary. However, each key-value pair also has an expiration time, after which the pair is automatically removed from the map. This allows for efficient storage and retrieval of data that is only relevant for a limited time period.

Key Features

Automatic expiration of key-value pairs based on TTL
Efficient storage of time-sensitive data
Retrieval of unexpired pairs based on keys
Ability to set TTL when adding or updating pairs
Removal of expired pairs during regular cleanup
Autosave to GitHub repository

Use Cases

Caching frequently accessed data with a limited lifetime
Tracking user sessions or other short-term user data
Storing temporary configuration settings or feature flags
Implementing rate limiting or throttling for APIs
Maintaining leaderboards or other temporary rankings

Show me the code

You can run this code with: deno run -r --env -A store.ts.

Create store instance: you have to prepare the repository and GITHUB_TOKEN if you want to save to Github repository.

Please note, the maximum size of the file is 100 MB.

import { Store } from "https://fastro.dev/core/map/mod.ts";

const store = new Store({
  owner: "fastrodev",
  repo: "fastro",
  branch: "store",
  path: "modules/store/store.json",
  token: Deno.env.get("GITHUB_TOKEN"),
});

Autosave the map to the repository in every 5s by default.

store.sync();

Check, set, and save it to the repository. Please note that committing takes some time. It takes around 3 seconds to save to GitHub.

store.set("key1", "hello");
store.check("key2").set("key2", "hello2", 4000);
await store.check("key3").set("key3", "hello3").commit();

Get the value from the map

const r1 = await store.get("key1");

Simulate the TTL and expiration

await new Promise((resolve) => setTimeout(resolve, 5000));
const r3 = await store.get("key2"); // undefined

Get the file from synced file

const r4 = await store.get("key3");

Clear and delete the map.

store.clear();

store.delete("key1");
store.delete("key3");

Destroy the file.

await store.destroy();

Example of use in web app

Fastro already integrate that class via Context.

You can find the full code on examples/store.ts

import fastro, { Context, HttpRequest } from "@app/mod.ts";

const f = new fastro();

// set default value for the store
f.store.set("hello", "hello world");

f.get(
  "/",
  (_req: HttpRequest, ctx: Context) => {
    // get the value
    const res = ctx.store.get("hello");
    return Response.json({ value: res });
  },
);

await f.serve();