[SPARK-46124][CORE][SQL][SS][CONNECT][DSTREAM][MLLIB][ML][PYTHON][R][AVRO][K8S][YARN][UI] Replace explicit ArrayOps#toSeq with s.c.immutable.ArraySeq.unsafeWrapArray

[LuciferYang]

What changes were proposed in this pull request?

There is a behavioral difference between Scala 2.13 and 2.12 for explicit ArrayOps.toSeq calls, similar to the implicit conversion from Array to Seq.

In Scala 2.12, ArrayOps.toSeq will return thisCollection , and use implicit conversion rules to wrap the Array as mutable.WrappedArray, this process does not involve any collection copy:

Welcome to Scala 2.12.18 (OpenJDK 64-Bit Server VM, Java 17.0.9).
Type in expressions for evaluation. Or try :help.

scala> Array(1,2,3).toSeq
res0: Seq[Int] = WrappedArray(1, 2, 3)

However, in Scala 2.13, it returns an immutable.ArraySeq that with collection copy.

Since we have always used the non-collection copy behavior for this explicit conversion in the era of Scala 2.12, it is safe to assume that no collection copy is needed for Scala 2.13.

Therefore, this pr replaces explicit ArrayOps.toSeq in the Spark code with s.c.immutable.ArraySeq.unsafeWrapArray to avoid a collection copy, and this pr only involves changes to the production code, and does not involve changes to the test code.

Why are the changes needed?

Replace ArrayOps#toSeq with s.c.immutable.ArraySeq.unsafeWrapArray to save a collection copy, which has potential benefits for performance."

Does this PR introduce any user-facing change?

No

How was this patch tested?

Pass GitHub Action

Was this patch authored or co-authored using generative AI tooling?

No

[LuciferYang]

cc @srowen, could you help to review this pr if you have time. Thanks

Similar to #43666, the purpose of this pr is also to save a collection copy by using immutable.ArraySeq.unsafeWrapArray . This pr does not modify similar cases in the test code, and I do not plan to fix test code parts for the time being.

[srowen]

Seems reasonable to me, continuing the same refactoring. Is it ready?

[LuciferYang]

Yes, it's ready

[LuciferYang]

@srowen this PR Is ready, should we push it forward?

[srowen]

Merged to master

[LuciferYang]

Thanks @srowen