Add length method to RandomAccessInput

[iverase]

Implementation is straight forward as we always have the length of the data when constructing a RandomAccessInput. The only odd thing is that ByteBuffersDataInput already has a method called size() so I deprecated it in favour of this new one.

closes #12592

[jpountz]

LGTM. Add a CHANGES entry?

[iverase]

Thanks @jpountz! What it is not clear to me is if adding a method to this interface is considered a breaking change and it can only be introduced in a major release, or if it can be backported to the 9.x line. Any suggestions?

[romseygeek]

I think it's fine to add simple methods to interfaces like this in point releases. Extending RandomAccessInput would be a pretty expert use of lucene.

One suggestion: given that ByteBuffersDataInput already has a size method, why not name the new interface method size as well? The two terms are more or less interchangeable, and that way you don't need to do all the deprecations.

[iverase]

One suggestion: given that ByteBuffersDataInput already has a size method, why not name the new interface method size as well? The two terms are more or less interchangeable, and that way you don't need to do all the deprecations.

Because IndexInput already defines a method called length, so adding a size method means that all the IndexInput that implements RandomAccessInput (which there are a few) will have a size and a length method which looks less ideal. But if folks thinks otherwise I don't feel strongly about it.

[romseygeek]

Because IndexInput already defines a method called length, so adding a size method means that all the IndexInput that implements RandomAccessInput (which there are a few) will have a size and a length method which looks less ideal

Ah right, no your way makes more sense then.