regexp_test.go

     1  // Copyright 2013 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  package go1
     6  
     7  import (
     8  	"math/rand"
     9  	"regexp"
    10  	"testing"
    11  )
    12  
    13  // benchmark based on regexp/exec_test.go
    14  
    15  var regexpText []byte
    16  
    17  func makeRegexpText(n int) []byte {
    18  	rand.Seed(0) // For reproducibility.
    19  	if len(regexpText) >= n {
    20  		return regexpText[:n]
    21  	}
    22  	regexpText = make([]byte, n)
    23  	for i := range regexpText {
    24  		if rand.Intn(30) == 0 {
    25  			regexpText[i] = '\n'
    26  		} else {
    27  			regexpText[i] = byte(rand.Intn(0x7E+1-0x20) + 0x20)
    28  		}
    29  	}
    30  	return regexpText
    31  }
    32  
    33  func benchmark(b *testing.B, re string, n int) {
    34  	r := regexp.MustCompile(re)
    35  	t := makeRegexpText(n)
    36  	b.ResetTimer()
    37  	b.SetBytes(int64(n))
    38  	for i := 0; i < b.N; i++ {
    39  		if r.Match(t) {
    40  			b.Fatal("match!")
    41  		}
    42  	}
    43  }
    44  
    45  const (
    46  	easy0  = "ABCDEFGHIJKLMNOPQRSTUVWXYZ$"
    47  	easy1  = "A[AB]B[BC]C[CD]D[DE]E[EF]F[FG]G[GH]H[HI]I[IJ]J$"
    48  	medium = "[XYZ]ABCDEFGHIJKLMNOPQRSTUVWXYZ$"
    49  	hard   = "[ -~]*ABCDEFGHIJKLMNOPQRSTUVWXYZ$"
    50  )
    51  
    52  func BenchmarkRegexpMatchEasy0_32(b *testing.B)  { benchmark(b, easy0, 32<<0) }
    53  func BenchmarkRegexpMatchEasy0_1K(b *testing.B)  { benchmark(b, easy0, 1<<10) }
    54  func BenchmarkRegexpMatchEasy1_32(b *testing.B)  { benchmark(b, easy1, 32<<0) }
    55  func BenchmarkRegexpMatchEasy1_1K(b *testing.B)  { benchmark(b, easy1, 1<<10) }
    56  func BenchmarkRegexpMatchMedium_32(b *testing.B) { benchmark(b, medium, 32<<0) }
    57  func BenchmarkRegexpMatchMedium_1K(b *testing.B) { benchmark(b, medium, 1<<10) }
    58  func BenchmarkRegexpMatchHard_32(b *testing.B)   { benchmark(b, hard, 32<<0) }
    59  func BenchmarkRegexpMatchHard_1K(b *testing.B)   { benchmark(b, hard, 1<<10) }
    60
View as plain text