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| author | Polina Osadcha <polliosa@google.com> | 2020-06-18 16:17:13 +0300 |
|---|---|---|
| committer | Martin Möhrmann <moehrmann@google.com> | 2020-08-17 04:08:35 +0000 |
| commit | 51ac0f0f4cb432204dee3d434335fd1e61ca8446 (patch) | |
| tree | 25ccafb124ef4de57b46d8156c026f8b636cbb82 /src/strings/strings.go | |
| parent | 6f99b33c18266a8858af96163de97173bdf6f081 (diff) | |
| download | go-51ac0f0f4cb432204dee3d434335fd1e61ca8446.tar.xz | |
strings: optimize Replace by using a strings.Builder
name old time/op new time/op delta
ReplaceAll 162ns ±26% 134ns ±26% -17.44% (p=0.014 n=10+10)
name old alloc/op new alloc/op delta
ReplaceAll 32.0B ± 0% 16.0B ± 0% -50.00% (p=0.000 n=10+10)
name old allocs/op new allocs/op delta
ReplaceAll 2.00 ± 0% 1.00 ± 0% -50.00% (p=0.000 n=10+10)
Change-Id: Ia8377141d3adb84c7bd94e511ac8f739915aeb40
Reviewed-on: https://go-review.googlesource.com/c/go/+/245197
Run-TryBot: Martin Möhrmann <moehrmann@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Diffstat (limited to 'src/strings/strings.go')
| -rw-r--r-- | src/strings/strings.go | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/src/strings/strings.go b/src/strings/strings.go index d6f5cea6e6..b429735fea 100644 --- a/src/strings/strings.go +++ b/src/strings/strings.go @@ -934,8 +934,8 @@ func Replace(s, old, new string, n int) string { } // Apply replacements to buffer. - t := make([]byte, len(s)+n*(len(new)-len(old))) - w := 0 + var b Builder + b.Grow(len(s) + n*(len(new)-len(old))) start := 0 for i := 0; i < n; i++ { j := start @@ -947,12 +947,12 @@ func Replace(s, old, new string, n int) string { } else { j += Index(s[start:], old) } - w += copy(t[w:], s[start:j]) - w += copy(t[w:], new) + b.WriteString(s[start:j]) + b.WriteString(new) start = j + len(old) } - w += copy(t[w:], s[start:]) - return string(t[0:w]) + b.WriteString(s[start:]) + return b.String() } // ReplaceAll returns a copy of the string s with all |