createDurableObjectStoragePersister

The createDurableObjectStoragePersister function creates a DurableObjectStoragePersister object that can persist the Store to and from Cloudflare Durable Object storage.

createDurableObjectStoragePersister(
  store: MergeableStore,
  storage: DurableObjectStorage,
  storagePrefix?: string,
  onIgnoredError?: (error: any) => void,
): DurableObjectStoragePersister

You will mostly use this within the createPersister method of a WsServerDurableObject.

A DurableObjectStoragePersister only supports MergeableStore objects, and cannot be used to persist a regular Store.

Durable Objects have limitations on the data that can be stored in each key of their key-value structure. The DurableObjectStoragePersister uses one key per TinyBase Value, one key per Cell, one key per Row, and one key per Table. Mostly this is CRDT metadata, but the main caution is to ensure that each individual TinyBase Cell and Value data does not exceed the (128 KiB) limit.

As well as providing a reference to the MergeableStore to persist, you must provide a storage parameter which identifies the Durable Object storage to persist it to.

import {WsServerDurableObject} from 'tinybase/synchronizers/synchronizer-ws-server-durable-object';
import {createDurableObjectStoragePersister} from 'tinybase/persisters/persister-durable-object-storage';
import {createMergeableStore} from 'tinybase';

export class MyDurableObject extends WsServerDurableObject {
  createPersister() {
    const store = createMergeableStore();
    const persister = createDurableObjectStoragePersister(
      store,
      this.ctx.storage,
    );
    return persister;
  }
}