Roku Developer Program

[umesh]

Hi,

My application requires to generate GUID. I searched online documentation and forum for generating GUID but couldn't find any API / method. It would be great if some one can point out how can i generate GUID using BrighScript .

Thanks and regards,
Tank

[TheEndless]

There's no built in utility to generate a GUID, but it wouldn't be hard to write something that generates a pseudo-guid. Before you go that route, though, do you need a guid specifically, or just a randomly generated unique ID?

[TheEndless]

Here's something I threw together really quick. It's not guaranteed unique, but you'd have to generate an awful lot of them before you'd get dupes...

Function GenerateGuid() As String
    ' Ex. {5EF8541E-C9F7-CFCD-4BD4-036AF6C145DA}
    Return "{" + GetRandomHexString(8) + "-" + GetRandomHexString(4) + "-" + GetRandomHexString(4) + "-" + GetRandomHexString(4) + "-" + GetRandomHexString(12) + "}"
End Function

Function GetRandomHexString(length As Integer) As String
    hexChars = "0123456789ABCDEF"
    hexString = ""
    For i = 1 to length
        hexString = hexString + hexChars.Mid(Rnd(16) - 1, 1)
    Next
    Return hexString
End Function

[umesh]

Thanks TheEndless for your response.
Yes i need GUID specifically not just a randomly generated unique ID. Main idea is to get unique ID each time app calls the function. Thanks for the sample code. It would be great if there is a guaranteed GUID generator.

[RokuMarkn]

You could implement a "name-based UUID" as per section 4.3 in RFC 4122. Use the device serial number from roDeviceInfo as the "node name".

--Mark

[umesh]

Thanks RokuMarkn,

This makes perfect sense. I think I can use RFC and combine it with couple of other params to generate GUID.
Still, i would say if BrightScript has build in support for GUID it would be easier for the developers 🙂

Thanks again for your time and help

[TheEndless]

Out of curiosity, why are you needing to generate unique GUIDs so often from within the channel, and are you really going to be generating so many that my psuedo-guid function won't work for you? With 32 randomly picked hex digits, I can't imagine you'd ever be likely to hit a duplicate.

[umesh]

TheEndless,
Thanks for your psuedo-guid, really appreciate it. It can work for me but I was little concerned about "It's not guaranteed unique". I don't want to introduce any bugs just because of the duplication. In my experience, this type of bugs are very difficult to track down because it appears only when there is a duplication and it may not appear in development environment at all.

Thanks again to all for the help 🙂

[destruk]

You could check for duplication and have it regenerate itself.

[RokuMarkn]

In many applications, one does not have access to all previously generated GUIDs, but I can't say if that's true for the OP.

If Rnd returned truly random numbers, TheEndless' algorithm would be pretty much as good as a real GUID. It's possible, although extremely unlikely, for real GUIDs, produced according to the RFC, to produce duplicates too. In TheEndless' algorithm, since Rnd is called in a predictable sequence, collisions are only as unlikely as two scripts starting with the same Rnd internal state, which actually isn't all that unlikely. Rnd is not a cryptographically strong RNG and it's probably not a good idea to use it as such.

--Mark