Use Grid instead of int as primary key.

[andy840119]

Instead of finding the largest index from the list of hit-object, like:

• SingerInfo.getNewSingerId();
• LyricsChangeHandler.getId();

maybe should be better to just use the GUID to prevent the duplicated id.

Another benefit:

• There's no need to deal with logic to re-sort the id([1,3,4] -> [1,2,3])
• Technically, there's no possible to have duplicated id.
• Able to generate the id inside the class, follow how SkinInfo did in the osu.game
• Easily to global search the id in the json file.

And note that:

• We can change the algorithm for make the unique id shorter or not easier to duplicated at any time.

[andy840119]

https://dvoituron.com/2022/04/07/generate-small-unique-identifier/
Seems GUID is too large, maybe should find another way to shorter the unique id's length.

[andy840119]

Those objects need the id:

Beatmap:

• Singer -> max 20 singers
• Lyric -> max 300 lyrics

Stage:

• StageElement(i'm not very sure if skin element really need to unique key) -> max 200 elements
• ClassicLyricTimingPoint(not really sure also.) -> max 2000 timing point.

Seems duplicated id is not the main issue.

[andy840119]

I think 7 characters as primary key is enough.
like how git generate the SHA1?

[andy840119]

And we need to make sure that the generated singer or lyric's id should not be null in the test case.

[andy840119]

Not very sure if it's over-design but we can follow how ResolvedAttribute did to assign the value to the primary key.

[andy840119]

Or maybe make the id has it's own struct?
E.g. TinyUuid or NanoUuid
see: https://stackoverflow.com/a/61777945/4105113

Or ShortId
see: https://stackoverflow.com/a/45987192/4105113

[andy840119]

Note:
Maybe Guid should accept the string format, so there will be no need to write it's own serializer.

See:
dotnet/runtime#31465

[andy840119]

There's the sample code how serialize/deserialize the Guid without customized serializer.
see:

[Test]
public static void GuidSerializationTest()
{
    string str = JsonConvert.SerializeObject(new Foo
    {
        MyGuid = Guid.NewGuid()
    });
    Assert.NotNull(str, str);
}

[Test]
public static void GuidDeserializationTest()
{
    Foo? f = JsonConvert.DeserializeObject<Foo>("{\"MyGuid\":\"090bbc52-bfe3-4fa3-9b36-25d7e624e662\"}");
    Guid expected = new Guid("090bbc52-bfe3-4fa3-9b36-25d7e624e662");
    Assert.AreEqual(expected, f?.MyGuid);
}

public class Foo
{
    public Guid MyGuid { get; set; }
}

[andy840119]

And note that we can make the "IHasPrimaryKey" interface in the Beatmap namespace.
Follow how IHasPrimaryKey and IHasGuidPrimaryKey did in the osu.Game.

[andy840119]

Only remaining the skin element need to change the element type.
But it's not the first priority.

[andy840119]

Guess should be able to close this issue because should not have the element id in the skin eventually.
It will let the skin in the karaoke beatmap hard to be replaced.