We should use `(*regexp.Regexp).MatchString` instead of
`(*regexp.Regexp).Match([]byte(...))` when matching string to avoid
unnecessary `[]byte` conversions and reduce allocations.
Example benchmark:
var grepRegex = regexp.MustCompile("foo.*")
func BenchmarkMatch(b *testing.B) {
for i := 0; i < b.N; i++ {
if match := grepRegex.Match([]byte("foo bar baz")); !match {
b.Fail()
}
}
}
func BenchmarkMatchString(b *testing.B) {
for i := 0; i < b.N; i++ {
if match := grepRegex.MatchString("foo bar baz"); !match {
b.Fail()
}
}
}
goos: linux
goarch: amd64
pkg: github.com/johnkerl/miller/pkg/transformers
cpu: AMD Ryzen 7 PRO 4750U with Radeon Graphics
BenchmarkMatch-16 5700908 210.3 ns/op 16 B/op 1 allocs/op
BenchmarkMatchString-16 8006731 156.4 ns/op 0 B/op 0 allocs/op
PASS
ok github.com/johnkerl/miller/pkg/transformers 2.857s
Signed-off-by: Eng Zer Jun <engzerjun@gmail.com>
