This change fixes an issue introduced in #17707. When a regex
with a wildcard, literal, and final wildcard surounded by a
capture group was parsed - the capture group was not removed
first preventing `optimizeConcatRegex` from running.
Found via fuzz testing.
Signed-off-by: Nick Pillitteri <nick.pillitteri@grafana.com>
#14173 introduced an optimisation to better handle regex patterns like .*-.*-.*. It identifies strings the pattern cannot possibly match (because they do not contain all of the literal values) and returns false from MatchString early.
However, if the string does contain all literal values, then the Go regex engine is used to confirm that the string does match the pattern. But this is not necessary in the case where the start and end of the pattern is .* and everything in between is either a literal or .*: if the string contains all of the literals in order, then it matches the pattern, and invoking Go's regex engine to confirm this is unnecessary and quite slow.
* Add some more test cases
* Add benchmark, since existing benchmark doesn't show much impact given most of the random test strings will not match the patterns.
Signed-off-by: Charles Korn <charles.korn@grafana.com>
See
https://pkg.go.dev/golang.org/x/tools/gopls/internal/analysis/modernize
for details.
This ran into a few issues (arguably bugs in the modernize tool),
which I will fix in the next commit, so that we have transparency what
was done automatically.
Beyond those hiccups, I believe all the changes applied are
legitimate. Even where there might be no tangible direct gain, I would
argue it's still better to use the "modern" way to avoid micro
discussions in tiny style PRs later.
Signed-off-by: beorn7 <beorn@grafana.com>
Up to 32-byte values this saves garbage, runs faster.
For prefixes, only `toLower` the part we need for the map lookup.
Split toNormalisedLower into fast and slow paths, to avoid a penalty
for the `copy` call in the case where no allocations are done.
Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
Shortcut for `.*` matches newlines as well.
Add preamble change ^(?s:
Add test
dotAll flag por al regex
Add and fix regex tests
Signed-off-by: Mario Fernandez <mariofer@redhat.com>
For example `foo.*|bar.*|baz.*`. Instead of checking each one in turn,
we build a map of prefixes, then check the smaller set that could match
the string supplied.
Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
* Improve testing and readability
Address review comments on #13843
Signed-off-by: Marco Pracucci <marco@pracucci.com>
* Converted string to standarized form
* Added golang.org/x/text in Go dependencies
* Added test cases for FastRegexMatcher
* Added benchmark for toNormalizedLower
Signed-off-by: RA <ranveeravhad777@gmail.com>
This adds some more test cases for unicode values, and also a benchmark
for zeroOrOneCharacterStringMatcher.Matches()
Signed-off-by: Oleg Zaytsev <mail@olegzaytsev.com>
When `zeroOrOneCharacterStringMatcher` wach checking the input string,
it assumed that if there are more than one bytes, then there are more
than one runes, but that's not necessarily true.
Signed-off-by: Oleg Zaytsev <mail@olegzaytsev.com>
The strings produced by these tests can run to thousands of characters,
which makes test logs difficult to read.
Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
This creates a new `model` directory and moves all data-model related
packages over there:
exemplar labels relabel rulefmt textparse timestamp value
All the others are more or less utilities and have been moved to `util`:
gate logging modetimevfs pool runtime
Signed-off-by: beorn7 <beorn@grafana.com>
