qbit/go
1
0
Fork 0
mirror of https://github.com/golang/go synced 2024-09-29 09:24:28 -06:00
Code Releases Activity

syscall: optimize Byte{Ptr,Slice}FromString

Browse Source 
Use bytealg.IndexByteString(str, 0) instead of looping through the
string to check for a zero byte. A quick and dirty benchmark shows 10x
performance improvement (on amd64 machine, using go 1.17.3).

BytePtrFromString is used by many functions with string arguments.
This change should make many functions in os package, such as those
accepting a filename (os.Open, os.Stat, etc.), a tad faster.

PS I am aware that syscall package is deprecated and frozen, but this
change is mainly for the os package and the likes. The alternative
would be for os to switch to x/sys, which is a much bigger change.

Change-Id: I18fdd50f9fbfe0a23a4a71bc4bd0a5f5b0eaa475
Reviewed-on: https://go-review.googlesource.com/c/go/+/368457
Reviewed-by: Tobias Klauser <tobias.klauser@gmail.com>
Reviewed-by: Emmanuel Odeke <emmanuel@orijtech.com>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
This commit is contained in:
Kir Kolyshkin 2021-12-01 19:48:58 -08:00 committed by Emmanuel Odeke
parent d6a1ffd624
commit 0d651041a9
1 changed files with 4 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
src/syscall/syscall.go
View File

@ -26,6 +26,8 @@
//
package syscall
import "internal/bytealg"
//go:generate go run ./mksyscall_windows.go -systemdll -output zsyscall_windows.go syscall_windows.go security_windows.go
// StringByteSlice converts a string to a NUL-terminated []byte,
@ -45,10 +47,8 @@ func StringByteSlice(s string) []byte {
// containing the text of s. If s contains a NUL byte at any
// location, it returns (nil, EINVAL).
func ByteSliceFromString(s string) ([]byte, error) {
for i := 0; i < len(s); i++ {
if s[i] == 0 {
return nil, EINVAL
}
if bytealg.IndexByteString(s, 0) != -1 {
return nil, EINVAL
}
a := make([]byte, len(s)+1)
copy(a, s)