How to apply expiry times to keys in HTML5 indexeddb?

Question

In indexedDB in html5 api, I can use it to store key-value pairs. But how can I make sure that after adding a certain key-value, after 1 day, that key should automatically be deleted from the db.

I was thinking of wrapping the value in an object with current datetime, and expiry time, and when u get the value, check the time difference, but is this the best way?

Thanks

Answer 1

Yep, what Scott Marcus and dgrogan said. One more hint: if you create an index on the timestamp, you can iterate a cursor over the range of "expired" values and delete them after opening the database.

const open = indexedDB.open("demo");

open.onupgradeneeded = function () {
  const db = open.result;
  const store = db.createObjectStore("store");
  const index = store.createIndex("timestamp", "timestamp");

  // Populate with some dummy data, with about half from the past:
  for (let id = 0; id < 20; ++id) {
    store.put(
      {
        value: Math.random(),
        timestamp: new Date(Date.now() + (Math.random() - 0.5) * 10000),
      },
      id
    );
  }
};

open.onsuccess = function () {
  const db = open.result;
  const tx = db.transaction("store", "readwrite");
  // Anything in the past:
  const range = IDBKeyRange.upperBound(new Date());

  tx
    .objectStore("store")
    .index("timestamp")
    .openCursor(range).onsuccess = function (e) {
    const cursor = e.target.result;
    if (!cursor) return;
    console.log("deleting: " + cursor.key);
    cursor.delete();
    cursor.continue();
  };

  // This transaction will run after the first commits since
  // it has overlapping scope:
  const tx2 = db.transaction("store");
  tx2.objectStore("store").count().onsuccess = function (e) {
    console.log("records remaining: " + e.target.result);
  };
};

Answer 2

Support for automatically expiring IndexedDB and other storage data is being considered. See https://github.com/whatwg/storage/issues/11. It would be helpful if you could describe your use case there.

In the meantime you'll have to do something like you outlined or what Scott Marcus suggests.

Answer 3

IndexedDB can only be modified by code. It has no automatic capabilities. Why not just store the data with a timestamp value and modify your code to remove it when the timestamp is out of date?