Olli Comments

yeah, actually that part makes sense. But when deleting them, I think there will be an issue since it might delete other thread entries with the same lastUpdated value?

13 replies

DDeno

•Created by Cheat-Code Sam on 5/25/2024 in #help

Indexing Items by Last Updated Time in Deno KV

Just a heads up, the id and lastUpdated parts of the secondary index key should maybe be flipped?

13 replies

DDeno

•Created by Cheat-Code Sam on 5/25/2024 in #help

Indexing Items by Last Updated Time in Deno KV

I see the issue. One way to go about it might be to delete the existing index entries and then setting the new one on every update, so that there is always only 1 copy of any given thread:

type Thread = {
  lastUpdated: string
  posts: unknown[]
}

const kv = await Deno.openKv()

async function createThread(id: string, thread: Thread) {
  await kv.atomic()
    .check({
      key: ["threads", id],
      versionstamp: null
    })
    .set(["threads", id], thread)
    .set(["threads", "last_updated", thread.lastUpdated, id], thread)
    .commit()
}

async function updateThread(id: string, thread: Thread) {
  // Get the current thread value
  const currentThread = await kv.get<Thread>(["threads", id])
  if (!currentThread.value) {
    // ...do something
    return
  }

  // Set the new thread entry
  const atomic = kv.atomic()
  atomic.set(["threads", id], thread)

  // Delete any existing index entries
  const iter = kv.list({ prefix: ["threads", "last_updated", currentThread.value.lastUpdated] })
  for await (const { key } of iter) {
    atomic.delete(key)
  }

  // Set the new index entry
  await atomic
    .set(["threads", "last_updated", thread.lastUpdated, id], thread)
    .commit()
}

type Thread = {
  lastUpdated: string
  posts: unknown[]
}

const kv = await Deno.openKv()

async function createThread(id: string, thread: Thread) {
  await kv.atomic()
    .check({
      key: ["threads", id],
      versionstamp: null
    })
    .set(["threads", id], thread)
    .set(["threads", "last_updated", thread.lastUpdated, id], thread)
    .commit()
}

async function updateThread(id: string, thread: Thread) {
  // Get the current thread value
  const currentThread = await kv.get<Thread>(["threads", id])
  if (!currentThread.value) {
    // ...do something
    return
  }

  // Set the new thread entry
  const atomic = kv.atomic()
  atomic.set(["threads", id], thread)

  // Delete any existing index entries
  const iter = kv.list({ prefix: ["threads", "last_updated", currentThread.value.lastUpdated] })
  for await (const { key } of iter) {
    atomic.delete(key)
  }

  // Set the new index entry
  await atomic
    .set(["threads", "last_updated", thread.lastUpdated, id], thread)
    .commit()
}

This might be a bit excessive, but I dont really see any way to use unique indexing when there is a timestamp and id involved.

13 replies