prometheus/labels
Brian Brazil 259847a6b1
Be smarter in how we look at matchers. (#572)
* Add unittests for PostingsForMatcher.

* Selector methods are all stateless, don't need a reference.

* Be smarter in how we look at matchers.

Look at all matchers to see if a label can be empty.

Optimise Not handling, so i!="2" is a simple lookup
rather than an inverse postings list.

All all the Withouts together, rather than
having to subtract each from all postings.

Change the pre-expand the postings logic to always do it before doing a
Without only. Don't do that if it's already a list.

The initial goal here was that the oft-seen pattern
i=~"something.+",i!="foo",i!="bar" becomes more efficient.

benchmark                                                            old ns/op     new ns/op     delta
BenchmarkHeadPostingForMatchers/n="1"-4                              5888          6160          +4.62%
BenchmarkHeadPostingForMatchers/n="1",j="foo"-4                      7190          6640          -7.65%
BenchmarkHeadPostingForMatchers/j="foo",n="1"-4                      6038          5923          -1.90%
BenchmarkHeadPostingForMatchers/n="1",j!="foo"-4                     6030884       4850525       -19.57%
BenchmarkHeadPostingForMatchers/i=~".*"-4                            887377940     230329137     -74.04%
BenchmarkHeadPostingForMatchers/i=~".+"-4                            490316101     319931758     -34.75%
BenchmarkHeadPostingForMatchers/i=~""-4                              594961991     130279313     -78.10%
BenchmarkHeadPostingForMatchers/i!=""-4                              537542388     318751015     -40.70%
BenchmarkHeadPostingForMatchers/n="1",i=~".*",j="foo"-4              10460243      8565195       -18.12%
BenchmarkHeadPostingForMatchers/n="1",i=~".*",i!="2",j="foo"-4       44964267      8561546       -80.96%
BenchmarkHeadPostingForMatchers/n="1",i!="",j="foo"-4                42244885      29137737      -31.03%
BenchmarkHeadPostingForMatchers/n="1",i=~".+",j="foo"-4              35285834      32774584      -7.12%
BenchmarkHeadPostingForMatchers/n="1",i=~"1.+",j="foo"-4             8951047       8379024       -6.39%
BenchmarkHeadPostingForMatchers/n="1",i=~".+",i!="2",j="foo"-4       63813335      30672688      -51.93%
BenchmarkHeadPostingForMatchers/n="1",i=~".+",i!~"2.*",j="foo"-4     45381112      44924397      -1.01%

Signed-off-by: Brian Brazil <brian.brazil@robustperception.io>
2019-04-09 11:59:45 +01:00
..
labels.go FromMap(), sorts and returns instead of calling New() (#433) 2018-11-14 13:43:03 +01:00
labels_test.go fix statick check errors (#475) 2019-01-02 19:48:42 +03:00
selector.go Be smarter in how we look at matchers. (#572) 2019-04-09 11:59:45 +01:00