LuciferYang opened a new pull request, #50346: URL: https://github.com/apache/spark/pull/50346
### What changes were proposed in this pull request? This pr changes the explicit `Iterable` types in Spark code to use `nonEmpty`/`isEmpty` for empty checks, replacing `Iterable.size > 0`/`Iterable.size == 0`. ### Why are the changes needed? For data structures that can only be confirmed as `Iterable`, since their specific data structure cannot be determined, using `Iterable.size > 0`/`Iterable.size == 0` for empty checks may trigger an iteration over the collection: https://github.com/scala/scala/blob/3f6bdaeafde17d790023cc3f299b81eaaf876ca3/src/library/scala/collection/IterableOnce.scala#L969-L982 ```scala /** The size of this $coll. * * $willNotTerminateInf * * @return the number of elements in this $coll. */ def size: Int = if (knownSize >= 0) knownSize else { val it = iterator var len = 0 while (it.hasNext) { len += 1; it.next() } len } ``` Therefore, it is best to use `nonEmpty`/`isEmpty` for empty checks to avoid potential performance issues: https://github.com/scala/scala/blob/3f6bdaeafde17d790023cc3f299b81eaaf876ca3/src/library/scala/collection/IterableOnce.scala#L946-L960 ```scala /** Tests whether the $coll is empty. * * Note: The default implementation creates and discards an iterator. * * Note: Implementations in subclasses that are not repeatedly iterable must take * care not to consume any elements when `isEmpty` is called. * * @return `true` if the $coll contains no elements, `false` otherwise. */ def isEmpty: Boolean = knownSize match { case -1 => !iterator.hasNext case 0 => true case _ => false } ``` ### Does this PR introduce _any_ user-facing change? No ### How was this patch tested? Pass GitHub Actions ### Was this patch authored or co-authored using generative AI tooling? No -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: reviews-unsubscr...@spark.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: reviews-unsubscr...@spark.apache.org For additional commands, e-mail: reviews-h...@spark.apache.org
