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#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>