Use LocalForage as storage adapter?

[lgleim]

Hi, I'm looking into using Kinto + Kino.js for an offline first mobile application. I'm planning on using Ionic/Cordova for the project and have previously been playing around a lot with PouchDB. One issue that keeps coming up is storage limitations and the issue, that iOS does not support IndexedDB.
PouchDB solves this by choosing from various different storage backends depending on the environment. In order to circumvent the storage limits in Cordova deployments the Cordova SQLite storage plugin or Cordova SQLite Plugin 2 may be used.
I have previously also heard a lot about localForage, also developed by Mozilla, which allows to adaptively select a storage backend depending on the environment and for which a cordova sqlite storage driver exists.

Would it be possible to provide a storage adapter based on LocalForage or does it lack crucial features such as indexing?

[lgleim]

This may be related to #16 (comment)

[lgleim]

After stumbling upon https://mail.mozilla.org/pipermail/kinto/2016-March/000094.html and https://mail.mozilla.org/pipermail/kinto/2016-March/000095.html I guess localForage is not really an option.
Alternatively I found the https://github.com/ABB-Austin/cordova-plugin-indexeddb-async plugin. This probably solves any remaining issue that might not be solved using the default innodb shim. The question that remains for me is how to deal with hitting the storage limits of various platforms. Any insights?

[leplatrem]

Hi!

Thank you for your detailed feedback!

provide a storage adapter based on LocalForage

As you read on the ML, it is possible to write a LocalForage adapter. It won't support transaction though.

how to deal with hitting the storage limits of various platforms

Maybe implementing a WebSQL adapter — like PouchDB — would be a valid approach here.
But what is the order of size of your data?

[lgleim]

The size of data (without attachements, which I plan to load on demand) is in the range of more then 5mb, potentially more then 50mb but nowhere near 500mb.
I am aware of the limitations with the query api however the same is true for PouchDB. I am not sure of couchbase lite solves this in a better way but since it is also based on sqlite internally, I do not expect much better performance either.

Instead of reimplementing with LocalForage I do think it is much easier to hack the cordova-plugin-indexeddb-async to always fallback to an sqlite-based backend (cf. hitachienergy/cordova-plugin-indexeddb-async#2).

[lgleim]

I'm closing this for now. Feel free to reopen if it becomes relevant again.

[agarwalkartik]

@lgleim Hey, I am also trying to solve a similar problem. Could you tell how did you finally overcome the memory limitations? Thanks!