Insertion order for Rows with SCassandra

[Alien2150]

Hello,

I think I found an issue with Quill (http://getquill.io/) vs SCassandra. Quill is using a mapping function and applies to that to case class. E.g "case class Token(user_id: String. used: Boolean)". When i now try to return a row in a test i try todo this:

PrimingRequest.queryBuilder()
.withQuery("SELECT user_id, used from TOKENS")
.withRows(row)
.build();

where row is:

Map[String, Any](
"used" -> false,
"user_id" -> "b94133a3-e35d-4c94-9463-d806a64afd71"
)

For some reason it seems that the order is than flipped around randomly. My assume is that there is some kind of "iterator" which is not respecting the insertion order. I managed to switch to ListMap on client - side and regarding to the logs its fine. But according to the server-response the order is been flipped:

Client:

[debug] - org.apache.http.wire - http-outgoing-0 >> "{"when":{"query":"SELECT user_id, used from TOKENS"},"then":{"variable_types":[],"rows":[{"user_id":"b94133a3-e35d-4c94-9463-d806a64afd71", "used":false}],"column_types":{"user_id":"ascii","used":"boolean"}}}"

Server:
[info] - org.scassandra.server.actors.ExecuteHandler - Found prime PreparedPrime(List(CqlAscii),Prime(List(Map(used -> false, used_id-> b94133a3-e35d-4c94-9463-d806a64afd71 .....

I think it can easily be fixed by using ListMap in the server storage.

[tolbertam]

Hi @Alien2150 , thanks for reporting this. I think the most import thing is that the column metadata in the response will match the order of the column data in the rows, so this should not be an issue unless the client is making some implicit assumptions about the order of data, which is not unusual, after all the datastax drivers allow users to retrieve column values by index as well.

I think your suggestion of using ListMap is likely the correct way to go. I think the change would need to be made in PrimeQuerySingle and a few other places (PrimePrepared, and maybe in the Rows type in the codec).

Did you want to give this a try? I could give this a look but have a busy week so may not be able to get to it for a while.

[Alien2150]

I can have a look and make a PR if that helps