[Question] Some objective values not found in Manifest?

[jgayfer]

I've been working on getting values for the weekly nightfall, and I'm having an issue fetching one of the 'challenges' from the Manifest database. The other two values are both there, but the third isn't for some reason.

The hash ID is 4148319260, and I'm looking in DestinyObjectiveDefinition. Does anyone know why this is happening?

[vthornheart-bng]

Hmm, that's odd - I see it in there, look for index 925 (name = "Speed of Dark"). Oh, could it be that the hash is being converted to an int instead of a uint in your code? I know this has tripped people up before. Let me know!

[jgayfer]

I'm not quite sure where 925 is coming from. I'm still a bit confused.

If the hashes are all unsigned ints, how come I am seeing negative values in my sqlite viewer? Could it be displaying the numbers as signed values?

[vthornheart-bng]

Ah, yeah - the index property of the contained item will be 925 when you pull it out of the database.

Indeed: sqlite viewer must be treating those as signed values. Convert your unsigned value into a signed one and make the query again in sqlite viewer, and you should find the result. It's the same limitation and trick that people had to pull in Destiny 1:

http://destinydevs.github.io/BungieNetPlatform/docs/Manifest
(take a look in here under "Entry IDs")

I still need to add a section to our wiki about the Manifest and these... er... quirks.

[jgayfer]

Ah! I got it working. You were right; Just had to convert the unsigned values into signed ones 🙂

I used this function to convert the number, if anyone else is having the same issue (Python).

def twos_comp_32(val):
    val = int(val)
     if (val & (1 << (32 - 1))) != 0:
        val = val - (1 << 32)
    return val

Thank you for your help!

[vthornheart-bng]

Sweet, no problem - and glad you got it working! That is definitely an extremely unintuitive problem with the Manifest, and warrants a new FAQ entry on my part (and eventual Wiki article about the manifest in general)

[artem-galas]

Hm...I don't understand how we can check signed or unsigned number?

[jgayfer]

If you're using unsigned, you'll never have negative numbers. Whereas with signed, you will (approximately half the time).

[vthornheart-bng]

@artem-galas A good, quick formula you can use to convert is the following, that'll convert the values when needed for you: (or you can do the bitshifting jgayfer is doing above of course! That's arguably faster and truer to what's actually happening under the surface, but whatever floats your boat)

if (hash < 0)
{
hash = hash + 4294967296;
}

That will push it up to its unsigned equivalent value.

... indeed, this is a most inconvenient hack, and one that the community has had to endure for quite some time. When we get around to putting out JSON files directly, this won't be an issue anymore (though you will have to convert strings to unsigned ints... but you're already having to do that, so I imagine that's a more obvious problem than this signed/unsigned problem)