code review 7480047: go/test/bench/go1: add regexp test

go/test/bench/go1: add regexp test

[r, 2013-03-12 22:51:33]

Hello golang-dev@googlegroups.com,

I'd like you to review this change to
https://code.google.com/p/go

[bradfitz, 2013-03-12 23:05:41]

Seed the randomness for more predictable results?

On Tue, Mar 12, 2013 at 3:51 PM, <r@golang.org> wrote:

> Reviewers: golang-dev1,
>
> Message:
> Hello golang-dev@googlegroups.com,
>
> I'd like you to review this change to
> https://code.google.com/p/go
>
>
> Description:
> go/test/bench/go1: add regexp test
>
> Please review this at
https://codereview.appspot.**com/7480047/<https://codereview.appspot.com/7480...
>
> Affected files:
>   A test/bench/go1/regexp_test.go
>
>
> Index: test/bench/go1/regexp_test.go
> ==============================**==============================**=======
> new file mode 100644
> --- /dev/null
> +++ b/test/bench/go1/regexp_test.**go
> @@ -0,0 +1,58 @@
> +// Copyright 2013 The Go Authors. All rights reserved.
> +// Use of this source code is governed by a BSD-style
> +// license that can be found in the LICENSE file.
> +
> +package go1
> +
> +import (
> +       "math/rand"
> +       "regexp"
> +       "testing"
> +)
> +
> +// benchmark based on regexp/exec_test.go
> +
> +var regexpText []byte
> +
> +func makeRegexpText(n int) []byte {
> +       if len(regexpText) >= n {
> +               return regexpText[:n]
> +       }
> +       regexpText = make([]byte, n)
> +       for i := range regexpText {
> +               if rand.Intn(30) == 0 {
> +                       regexpText[i] = '\n'
> +               } else {
> +                       regexpText[i] = byte(rand.Intn(0x7E+1-0x20) + 0x20)
> +               }
> +       }
> +       return regexpText
> +}
> +
> +func benchmark(b *testing.B, re string, n int) {
> +       r := regexp.MustCompile(re)
> +       t := makeRegexpText(n)
> +       b.ResetTimer()
> +       b.SetBytes(int64(n))
> +       for i := 0; i < b.N; i++ {
> +               if r.Match(t) {
> +                       b.Fatal("match!")
> +               }
> +       }
> +}
> +
> +const (
> +       easy0  = "ABCDEFGHIJKLMNOPQRSTUVWXYZ$"
> +       easy1  = "A[AB]B[BC]C[CD]D[DE]E[EF]F[**FG]G[GH]H[HI]I[IJ]J$"
> +       medium = "[XYZ]**ABCDEFGHIJKLMNOPQRSTUVWXYZ$"
> +       hard   = "[ -~]***ABCDEFGHIJKLMNOPQRSTUVWXYZ$"
> +)
> +
> +func BenchmarkRegexpMatchEasy0_32(b *testing.B)  { benchmark(b, easy0,
> 32<<0) }
> +func BenchmarkRegexpMatchEasy0_1K(b *testing.B)  { benchmark(b, easy0,
> 1<<10) }
> +func BenchmarkRegexpMatchEasy1_32(b *testing.B)  { benchmark(b, easy1,
> 32<<0) }
> +func BenchmarkRegexpMatchEasy1_1K(b *testing.B)  { benchmark(b, easy1,
> 1<<10) }
> +func BenchmarkRegexpMatchMedium_32(**b *testing.B) { benchmark(b,
> medium, 1<<0) }
> +func BenchmarkRegexpMatchMedium_1K(**b *testing.B) { benchmark(b,
> medium, 1<<10) }
> +func BenchmarkRegexpMatchHard_32(b *testing.B)   { benchmark(b, hard,
> 32<<0) }
> +func BenchmarkRegexpMatchHard_1K(b *testing.B)   { benchmark(b, hard,
> 1<<10) }
>
>
> --
>
> ---You received this message because you are subscribed to the Google
> Groups "golang-dev" group.
> To unsubscribe from this group and stop receiving emails from it, send an
> email to
golang-dev+unsubscribe@**googlegroups.com<golang-dev%2Bunsubscribe@googlegrou...
> .
> For more options, visit
https://groups.google.com/**groups/opt_out<https://groups.google.com/groups/o...
> .
>
>
>

[r, 2013-03-12 23:11:08]

Hello golang-dev@googlegroups.com, bradfitz@golang.org (cc:
golang-dev@googlegroups.com),

Please take another look.

[bradfitz, 2013-03-12 23:20:27]

https://codereview.appspot.com/7480047/diff/7001/test/bench/go1/regexp_test.go
File test/bench/go1/regexp_test.go (right):

https://codereview.appspot.com/7480047/diff/7001/test/bench/go1/regexp_test.g...
test/bench/go1/regexp_test.go:18: rand.Seed(0) // For reproducibility.
better would be in makeRegexpText, so running:

go test -bench=.
and
go test -bench=RegexpMatchMedium
and
go test -bench=Regexp

... are all comparable.  Currently they're not.

[r, 2013-03-12 23:40:49]

Hello golang-dev@googlegroups.com, bradfitz@golang.org (cc:
golang-dev@googlegroups.com),

Please take another look.

[bradfitz, 2013-03-12 23:47:22]

LGTM

[r, 2013-03-12 23:50:12]

*** Submitted as https://code.google.com/p/go/source/detail?r=a81eca2d85b3 ***

go/test/bench/go1: add regexp test

R=golang-dev, bradfitz
CC=golang-dev
https://codereview.appspot.com/7480047