Reusing the field operation sorting for other things caused me
to hit a bug, also made me curious about a performance issue and
whether it was possible to improve it. Answer: Not easy to improve,
anyway.
This partially-implemented prototype of the ingest API is based on our
programmatic ingest API reference. It has noticable limitations, most
crucially that it doesn't handle multi-node clusters right now. However,
it basically implements the expected semantics.
There's some noticeable performance issues to do with the high overhead
of sorting bits in order to import them efficiently, but this is fixable.
We also add the hooks to the internal client, and make the finisher logic
a bit smarter.
Much of this code was originally by Nia Weiss, but it's been merged
and restructured a bit to get things broken into logical commits.
