Add BenchmarkChunkQueryableFromTar

[codesome]

BenchmarkChunkQueryableFromTar is same as TestChunkTar in pkg/querier/chunk_tar_test.go. This benchmark would come handy in investigating a query offline.

[bboreham]

Can you factor out the common code?

[codesome]

Done

[bboreham]

What is the reason the remaining code is different between the benchmark and the test?
Looks like a limit and a timeout.

[codesome]

Yes, I was not sure if I should alter those limits (samples and timeout) for TestChunkTar. And I was hitting both the limits when I was doing some benchmarks locally, so increased the limits for the benchmark.

Also, I would need calling b.ResetTimer() and b.ReportAllocs() for the benchmark, so the common code would be the one before that.

[bboreham]

If you can explain why the limits need to be different, please put that in a comment.
If not, remove the difference.

I don't usually put ReportAllocs() in the code because it is available as a command-line option -benchmem

[codesome]

Made the limits same, and removed b.ReportAllocs().

[bboreham]

so more of the code can be shared now?

[codesome]

b.ResetTimer() was in between. I will try sharing more code.

[codesome]

And done!

[bboreham]

🎉

[tomwilkie]

👍 LGTM