Use Java's least common denominator for random access lists

[karypid]

Hi,

Could you accept this minor change so that we can do unordered removals using AbstractList instead of ArrayList? Seems a pity/inconsistent to not be able to use this on org.agrona.collections.IntArrayList and org.agrona.collections.LongArrayList.

An alternative would be to have the latter extend ArrayList instead of AbstactList.

This would of course cause boxing in the "list.set(index, list.remove(lastIndex));" line so maybe it's even better to just add a "removeUnordered" in IntArrayList / LongArrayList themselves?

[karypid]

Are you referring to the name of the org.agrona.collections.ArrayListUtil class that I modified? It was already named as such, I did not want to change it because it might break API with client code (e.g. Aeron) that uses it.

I think the name of this class was meant to point out that it is supposed to be used on direct-access lists (array based) otherwise "fastUnorderedRemove" is not really fast. Right now it picks the last item and uses it to overwrite the item being removed (reducing the collection size by 1).

Like I said, I wanted to use it in combination with org.agrona.collections.IntArrayList and org.agrona.collections.LongArrayList but these extend java.util.AbstractList.

I actually changed my mind now; I think it's better to just implement these as methods in IntArrayList/LongArrayList to make sure there is no boxing of the primitives possible so I am closing this. I will submit a request to add fast unordered remove in those 2 instead.