Mirrors/miller
1
0
Fork 0
mirror of https://github.com/johnkerl/miller.git synced 2026-01-23 02:14:13 +00:00
Code Issues Projects Releases Wiki Activity

lib/regex: use string version of regexp methods to reduce allocs (#1614)

Browse source 
Both `(*Regexp).Match` and `(*Regexp).FindAllSubmatchIndex` have
string-based equivalents: `(*Regexp).MatchString` and
`(*Regexp).FindAllStringSubmatchIndex`. We should use the string version
to avoid unnecessary `[]byte` conversions.

Benchmark:

var regex = regexp.MustCompile("foo.*")

func BenchmarkMatch(b *testing.B) {
	for i := 0; i < b.N; i++ {
		if match := regex.Match([]byte("foo bar baz")); !match {
			b.Fail()
		}
	}
}

func BenchmarkMatchString(b *testing.B) {
	for i := 0; i < b.N; i++ {
		if match := regex.MatchString("foo bar baz"); !match {
			b.Fail()
		}
	}
}

func BenchmarkFindAllSubmatchIndex(b *testing.B) {
	for i := 0; i < b.N; i++ {
		if match := regex.FindAllSubmatchIndex([]byte("foo bar baz"), -1); len(match) == 0 {
			b.Fail()
		}
	}
}

func BenchmarkFindAllStringSubmatchIndex(b *testing.B) {
	for i := 0; i < b.N; i++ {
		if match := regex.FindAllStringSubmatchIndex("foo bar baz", -1); len(match) == 0 {
			b.Fail()
		}
	}
}

goos: linux
goarch: amd64
pkg: github.com/johnkerl/miller/pkg/lib
cpu: AMD Ryzen 7 PRO 4750U with Radeon Graphics
BenchmarkMatch-16                         	 2198350	       517.5 ns/op	      16 B/op	       1 allocs/op
BenchmarkMatchString-16                   	 3143605	       371.5 ns/op	       0 B/op	       0 allocs/op
BenchmarkFindAllSubmatchIndex-16          	  921711	      1199 ns/op	     273 B/op	       3 allocs/op
BenchmarkFindAllStringSubmatchIndex-16    	 1212321	       981.0 ns/op	     257 B/op	       2 allocs/op
PASS
coverage: 0.0% of statements
ok  	github.com/johnkerl/miller/pkg/lib	6.576s

Signed-off-by: Eng Zer Jun <engzerjun@gmail.com>
This commit is contained in:
Eng Zer Jun 2024-08-10 01:09:53 +08:00 • committed by GitHub
parent dfe1ca1164
commit 3966a6a0a1
No known key found for this signature in database
GPG key ID: B5690EEEBB952194
1 changed files with 5 additions and 5 deletions
Download patch file Download diff file Expand all files Collapse all files

10
pkg/lib/regex.go
View file

@ -202,7 +202,7 @@ func regexCompiledSubOrGsub(
replacementCaptureMatrix [][]int,
breakOnFirst bool,
) string {
matrix := regex.FindAllSubmatchIndex([]byte(input), -1)
matrix := regex.FindAllStringSubmatchIndex(input, -1)
if matrix == nil || len(matrix) == 0 {
return input
}
@ -290,7 +290,7 @@ func RegexCompiledMatchSimple(
input string,
regex *regexp.Regexp,
) bool {
return regex.Match([]byte(input))
return regex.MatchString(input)
}
// RegexStringMatchWithMapResults implements much of the `strmatchx` DSL function. This returns
@ -320,7 +320,7 @@ func RegexCompiledMatchWithMapResults(
starts := make([]int, 0, 10)
ends := make([]int, 0, 10)
matrix := regex.FindAllSubmatchIndex([]byte(input), -1)
matrix := regex.FindAllStringSubmatchIndex(input, -1)
if matrix == nil || len(matrix) == 0 {
return false, captures, starts, ends
}
@ -406,7 +406,7 @@ func RegexCompiledMatchWithCaptures(
input string,
regex *regexp.Regexp,
) (bool, []string) {
matrix := regex.FindAllSubmatchIndex([]byte(input), -1)
matrix := regex.FindAllStringSubmatchIndex(input, -1)
if matrix == nil || len(matrix) == 0 {
// Set all captures to ""
return false, make([]string, 10)
@ -474,7 +474,7 @@ func ReplacementHasCaptures(
matrix [][]int,
) {
if captureDetector.MatchString(replacement) {
return true, captureSplitter.FindAllSubmatchIndex([]byte(replacement), -1)
return true, captureSplitter.FindAllStringSubmatchIndex(replacement, -1)
} else {
return false, nil
}