any plans to support persistence for Browser like leveldb

[Volland]

Cozo wasm module is amazing but lacks persistence for in-browser apps .
Support of leveldb or any browser-based persistence could open a lot of usecases

[chuanqisun]

In the interim, I've been using json-based export/import relations against browser's origin private filesystem. It isn't the fastest solution but provides the functionality. Ideally I'd love to have the ability to load and save data in binary.

[simonwh]

@chuanqisun We've done something similar, with in-memory cozo + localstorage (instead of origin private filesystem). We find it's working-ish. It's not super stable, and definitely not a long-term solution :) Would be interest to hear how you implemented it. Do you export/write file after every cozo operation? Or periodically? And then import on page load?

[chuanqisun]

@simonwh, my technique isn't ideal either. Exporting on every transaction causes performance issue. My workaround:

• Run the cozo wasm from a worker thread, so all the database I/O is isolated from the UI thread
• Export only upon user request, leading to data loss when user closes the app without saving.

In my opinion, a good continuous export implementation is a balancing act between the inevitable tradeoff between performance and data integrity. A few ideas I find useful:

• Use requestIdleCallback to let the browser pick a best moment to export but that won't work in Safari.
• Use some throttle and debounce techniques to reduce the export frequency
• Compare the stringified values and perform the export only when the value changes.

[94bryanr]

I am also interested in this. A few thoughts:

• Enabling the sqlite backend for wasm targets may be possible. See this PR to do so in rusqlite as an example.
• Could there be an addition to the current in-memory API so that you could optionally pass an impl of e.g. std::io::Write as an alternative location to write to? Then persisting to OPFS or localstorage would be relatively easy.

[davidhmays]

I would love browser based persistentence for local first applications.

I wonder if saving to ElectricSQL would be possible, enabling automatic sync to a back end as well?