I have checked the FSDirectory, it will create MMapDirectory or
NIOFSDirectory for Directory.
This two directory only supply IndexInput extend for read file (MMapIndexInput
extends ByteBufferIndexInput),
why not there is not MMap/NIO IndexOutput extend for file write. It only use
FSIndexOutput
Output is quite a bit simpler than input because all we do is write a
single stream of bytes with no seeking (append only), and it's done
with only one thread, so I don't think there'd be much to gain by
using the newer IO APIs for writing...
Mike McCandless
http://blog.mikemccandless.com
On
