Auto delete key from Deno.openKv() at a specific time or after a time;

[alaminkouser]

I am lucky to get early access to Deno.openKv() in Deno Deploy. I was just playing with it. I made a very simple function which redirects users to a url.

How it works/How to use it:
Deploy url is: https://307.deno.dev
If a user want to create a redirect url then he needs to add desired url in the path of the url.
Example 1: https://307.deno.dev/{target_url}
Example 2: https://307.deno.dev/https://example.com

User will get a url in response. If any user opens that url then it will redirect to targeted url.

This is my deploy code:

const kv = await Deno.openKv();

async function main(
  reqEvt: Deno.RequestEvent,
): Promise<Response> {
  const _kv: Deno.KvEntry<unknown>[] = [];
  for await (const entry of kv.list({ prefix: ["307"] })) {
    if (parseInt(entry.key[2].toString()) + 86400000 < Date.now()) {
      kv.delete(entry.key);
    } else {
      _kv.push(entry);
    }
  }
  if (new URL(reqEvt.request.url).pathname === "/") {
    return new Response("GUIDE");
  } else {
    const path = new URL(reqEvt.request.url).pathname.slice(1) +
      new URL(reqEvt.request.url).search;

    if (isURL(path) === true) {
      const id = crypto.randomUUID().replaceAll("-", "");
      await kv.set(["307", id, Date.now()], path);
      return new Response("http://307.deno.dev/" + id);
    } else {
      let redirectURL = "";
      _kv.forEach((entry) => {
        if(entry.key[1] === path) {
          redirectURL = entry.value as string;
        }
      });
      if (redirectURL !== "") {
        return Response.redirect(redirectURL, 307);
      } else {
        return Response.redirect("https://307.deno.dev/", 307);
      }
    }
  }
}

function isURL(url: string): boolean {
  if (!/^https?:\/\//.test(url)) {
    return false;
  }
  if (/[^a-zA-Z0-9-._~:/?#=]/.test(url)) {
    return false;
  }
  return true;
}

async function handle(conn: Deno.Conn) {
  try {
    for await (const requestEvent of Deno.serveHttp(conn)) {
      await requestEvent.respondWith(
        main(requestEvent),
      );
    }
  } catch (error) {
    console.log(error);
  }
}

const server = Deno.listen({
  port: 8000,
});

for await (const conn of server) {
  handle(conn);
}

I want to keep the key for 1 day. Then the key will expire. But Now I have to add timestamp in each key. And I have to loop through all keys then delete keys that are older than 1 day.

Can openKv perform auto deletion of keys based on time or after a certain time?

[csvn]

I've been interested also in the possibility to set an "experitation time" for data stored. Since clearing out expired data is a background job, it does not feel like the right fit to clear out data when performing other requests.

If there were some way to run background tasks, I would be fine with not having an explicit API for how long data should last before auto-deletion, though it would still be a neat feature to support it in KV directly.

[jwenjian]

+1 for this feature.

I was planning to migrate my visitor-badge service to deno deploy and kv, but I did not find similar data expiring strategy, so I just setup a deno deployment and make it works for me only, like below badge:

Sample code for visitor badge in deno: https://github.com/jwenjian/visitor-badge-deno

[csvn]

I believe this issue is solved by #20091, released in Deno v1.36.2. It adds a expireIn option (ms) to the set method for Deno KV.