`BufferedSeriesIterator` and `MemoizedSeriesIterator` use a method
called `Values` for exactly the purpose for which all other iterators
of the same kind use a method called `At`. That alone is confusing,
but on top of that, the `Values` method only returns a single sample,
not multiple values. I assume the naming has historical reasons. This
commit makes it more consistent. It is now easier to read, and now
`BufferedSeriesIterator` and `MemoizedSeriesIterator` implement
`chunkenc.Iterator` like many other iterators, too.
Signed-off-by: beorn7 <beorn@grafana.com>
- Pick At... method via return value of Next/Seek.
- Do not clobber returned buckets.
- Add partial FloatHistogram suppert.
Note that the promql package is now _only_ dealing with
FloatHistograms, following the idea that PromQL only knows float
values.
As a byproduct, I have removed the histogramSeries metric. In my
understanding, series can have both float and histogram samples, so
that metric doesn't make sense anymore.
As another byproduct, I have converged the sampleBuf and the
histogramSampleBuf in memSeries into one. The sample type stored in
the sampleBuf has been extended to also contain histograms even before
this commit.
Signed-off-by: beorn7 <beorn@grafana.com>
