diff options
| author | qmuntal <quimmuntal@gmail.com> | 2022-08-22 18:25:29 +0200 |
|---|---|---|
| committer | Gopher Robot <gobot@golang.org> | 2022-08-23 20:36:49 +0000 |
| commit | d88560afd32d18d8c9c3b31c41ae9877ca292e1d (patch) | |
| tree | dbb9bd37458e61e7feb4877a79216edd43cf3934 /src/syscall | |
| parent | fc0d423789e3a2e1f84801be14ac657d41c115e4 (diff) | |
| download | go-d88560afd32d18d8c9c3b31c41ae9877ca292e1d.tar.xz | |
syscall: rely on utf16.AppendRune
Using utf16.AppendRune instead of utf16.Encode safe a bunch
of allocations across the board, as many higher level functions
use it to call Windows syscalls, for example to `os` package:
name old alloc/op new alloc/op delta
Readdirname-12 15.6kB ± 0% 15.6kB ± 0% +0.26% (p=0.008 n=5+5)
Readdir-12 29.4kB ± 0% 29.4kB ± 0% +0.14% (p=0.008 n=5+5)
ReadDir-12 29.4kB ± 0% 29.4kB ± 0% +0.14% (p=0.016 n=4+5)
StatDot-12 552B ± 0% 560B ± 0% +1.45% (p=0.008 n=5+5)
StatFile-12 512B ± 0% 336B ± 0% -34.38% (p=0.008 n=5+5)
StatDir-12 432B ± 0% 288B ± 0% -33.33% (p=0.008 n=5+5)
LstatDot-12 552B ± 0% 560B ± 0% +1.45% (p=0.008 n=5+5)
LstatFile-12 512B ± 0% 336B ± 0% -34.38% (p=0.008 n=5+5)
LstatDir-12 432B ± 0% 288B ± 0% -33.33% (p=0.008 n=5+5)
StatFile-12 4.00 ± 0% 2.00 ± 0% -50.00% (p=0.008 n=5+5)
StatDir-12 4.00 ± 0% 2.00 ± 0% -50.00% (p=0.008 n=5+5)
LstatFile-12 4.00 ± 0% 2.00 ± 0% -50.00% (p=0.008 n=5+5)
LstatDir-12 4.00 ± 0% 2.00 ± 0% -50.00% (p=0.008 n=5+5)
Updates #51786
Change-Id: I0a088cf1a96e9c304da9311bb3895b70443c1637
Reviewed-on: https://go-review.googlesource.com/c/go/+/425054
Reviewed-by: Tobias Klauser <tobias.klauser@gmail.com>
Run-TryBot: Ian Lance Taylor <iant@google.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
Auto-Submit: Ian Lance Taylor <iant@google.com>
Diffstat (limited to 'src/syscall')
| -rw-r--r-- | src/syscall/syscall_windows.go | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/src/syscall/syscall_windows.go b/src/syscall/syscall_windows.go index ebaf84343d..c58d972e61 100644 --- a/src/syscall/syscall_windows.go +++ b/src/syscall/syscall_windows.go @@ -43,7 +43,13 @@ func UTF16FromString(s string) ([]uint16, error) { if bytealg.IndexByteString(s, 0) != -1 { return nil, EINVAL } - return utf16.Encode([]rune(s + "\x00")), nil + // In the worst case all characters require two uint16. + // Also account for the terminating NULL character. + buf := make([]uint16, 0, len(s)*2+1) + for _, r := range s { + buf = utf16.AppendRune(buf, r) + } + return utf16.AppendRune(buf, '\x00'), nil } // UTF16ToString returns the UTF-8 encoding of the UTF-16 sequence s, |