Quota Management API Review Notes

quota-management-review.md

Notes

• References to storage specs seem a bit off.

  • WEBSTORAGE is in HTML now, right?
  • FileSystem APIs are too in flux
  • WebSQL is dead

• The Promise interface is currently defined and discussed in the WHATWG DOM specification.

  Should reference ES6

• In the example, initializeCache needs a bit more explaining that it's a user cache

• StorageInfo should not be a [NoInterfaceObject] interface, with a prototype and everything. It should just be a dictionary. In other words, it should have Object.prototype as its prototype, instead of StorageInfo.prototype, where StorageInfo is an un-callable function.

• Actually, the same applies to StorageQuota, for different reasons. It's used as a namespace, not as a class, and WebIDL dictionaries match that better I think. (I dunno, this might not be a battle worth fighting; I guess this is just how navigator-extending specs work these days. You create a non-constructable class with the appropriate methods, somehow magically construct an instance of that class, then make that instance a property of navigator. Wheeeeee.)

• readonly attribute StorageType[] supportedTypes;: we should make sure this is a frozen array object, as per recent discussion by Jonas et al. in that bug. I assume this cannot change at runtime (but this would be good for the spec to clarify)

• Use DOMException to reject promises, not DOMError.

• StorageWatcher could benefit from an example.

• StorageWatcher rate parameter should probably be in milliseconds, not seconds---timespans in JavaScript are usually milliseconds.

Nitpicks

Examples

this section probably needs to be marked non-normative

optinally

typo

Positive Feedback

Constructors for StorageWatcher and StorageEvent, yay!

Pretty nice promise usage and verbiage, modulo the DOMError snafu.

Overall, very nice, simple, and idiomatic.

Two moments:

1. In my opinion, API should provide methods both for increasing and descreasing quota. I could imagine a webapp that allows user to set desirable size of local cache.
2. We may also expand quota functionality a bit further to make it possible to obtain details on quota usage by different types of storage (i.e. how much space IndexedDB or localStorage uses). I think it might be usable in some situations.