When building a CFS file, and also when merging stored fields (and
term vectors, with
LUCENE-1120), we copy large blocks of bytes at
once.
We currently do this with an intermediate buffer.
But, nio.transferTo should be somewhat faster on OS's that offer low
level IO APIs for moving blocks of bytes between files.
Improvement
Resolved
Minor
Use nio.transferTo when copying large blocks of bytes
