The actual code here is mostly jaffee's, but I've reworked it some.
This doesn't directly seem to be using UnionInPlace, but really it
is.
The actual logic inside (*Row).Union is a mess and probably silly
in a few ways, but hardly matters. The important part is that,
instead of calling it once per child as we get them, we gather
all of them at once and then call it on all of them. That gets
us a call to (*Row).Union that does a very elaborate dance to
compute a call to (*rowSegment).Union on the only segment present
in each of those rows, which then does a simpler thing to
call (*Bitmap).Union() with the first response as a receiver
and the rest as parameters, and THAT then ends up calling either
unionIntoTargetSingle() if there's only one other bitmap,
or using UnionInPlace on a Freeze() of the first bitmap, which
gets us (we hope) the benefits of the fancy UnionInPlace logic.
Every part of this is a reminder that we really need to replace
roaring and also the Row/rowSegment stuff some day.
staticcheck points out that the break is otherwise an ineffective
break because it just ends the current case clause of the switch
it's in, which is true.
This works around an issue where unreplicated keys will not be matched everywhere.
This also avoids the cost of creating millions of bolt read transactions and allocating strings.
The GetTx logic is deeply broken, this DOES NOT fix the underlying
bug.
When any call anywhere in a given set of calls has a top-level write,
we perform all transactions as write transactions, and we do not cache or
share those transactions. This means that anything which causes a
second GetTx for the same index/shard deadlocks against itself.
The two easy to find cases by casual inspection are time quantums
and Not queries, so this addresses those, but this should NOT be
considered a general fix.
Attributes are unmaintained and unused.
They have become more of a liability than a benefit.
This change eliminates them from the codebase.
The only user-visible change (assuming that attrs are not used) is that the attrs field will no longer appear in row JSON.
The existence field wasn't working because runs were broken for filters in
RBF. Fixing that allows us to simplify the logic. Also, we reuse the
findExisting filter because the filter's cached collection of containers
can be reused between things, allowing us to reduce allocations when
there's a lot of views.
