Replace HexIntegerField with a CharField

[jleclanche]

HexIntegerField has been the source of many issues for some database backends. It's not really worth the trouble, especially as it makes it hard to search the field by hex and impossible by partial hex.

Replacing this needs a design plan that will account for migrating existing DBs.

Open for the taking.

[matthewh]

@jleclanche I agree - this is causing me some headache right now. Would you accept this also in 1.5?

[jleclanche]

Probably not; I think this is a really backwards incompatible item. I could see it in 1.6 if there is one.

[matthewh]

I tend to look at it as relaxing the requirement. Any old value would still be accepted but would now be a string. I'm not keen on the idea of going through all this work and still needing to maintain a my own branch for production.

[jleclanche]

It requires a data migration though which I'm not a fan of working into 1.5.

[matthewh]

But you'd accept making it a UUIDField like APNS and WNS for 2.0?

[jleclanche]

Sure.

[jleclanche]

Actually, what do you mean exactly? UUIDs are 128bit, the hexints are 64.

[matthewh]

I was leaning towards converting any non-UUID value into a UUID using UUID5. The benefit here is all platform device_ids are now uuids. It would be transparent when adding device_ids to the system as we could convert any non-UUID into a uuid. We can also apply the same logic when filtering. This would allow application developers to use alternative values to the expected device_ids in situations where they have a more reliable way to determine the device id than indicated by the vendor.

[jleclanche]

Why uuid5?

[matthewh]

UUID5 is based on a SHA-1 hash of a namespace identifier, a UUID we can specify, and a string, the device_id. This basically lets us create hashes using uuids for sources that are not uuids.

Alternatively, consider switching device_id to just a CharField across the board and let application developers treat it however they deem necessary.

[jleclanche]

I'd rather switch to a uuidfield which is zero-padded on the leftmost 64-bit.

[matthewh]

I'd be willing to try that but I wonder if it would validate.

[matthewh]

Switching to a UUIDField that is zero-padded is pretty trivial. I'll get a PR ready.

>>> import uuid
>>> uuid.UUID(int=123)
UUID('00000000-0000-0000-0000-00000000007b')