TheArchive/tailscale
1
0
Fork 0
mirror of https://github.com/tailscale/tailscale.git synced 2025-02-21 04:18:38 +00:00
Code Issues Packages Projects Releases Wiki Activity

control/controlclient: cache Windows version

Browse Source 
To atone for 1d7f9d5b4a59b3e, the revert of 4224b3f73110f6f.

At least it's fast again, even if it's shelling out to cmd.exe (once now).

Updates #1478

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
This commit is contained in:
Brad Fitzpatrick 2021-03-15 21:38:42 -07:00
parent 1d7f9d5b4a
commit 6fbc9b3a98
1 changed files with 9 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

9
control/controlclient/hostinfo_windows.go
View File

@ -7,6 +7,7 @@ package controlclient
import ( import (
"os/exec" "os/exec"
"strings" "strings"
"sync/atomic"
"syscall" "syscall"
) )
@ -14,7 +15,12 @@ func init() {
osVersion = osVersionWindows osVersion = osVersionWindows
} }
var winVerCache atomic.Value // of string
func osVersionWindows() string { func osVersionWindows() string {
if s, ok := winVerCache.Load().(string); ok {
return s
}
cmd := exec.Command("cmd", "/c", "ver") cmd := exec.Command("cmd", "/c", "ver")
cmd.SysProcAttr = &syscall.SysProcAttr{HideWindow: true} cmd.SysProcAttr = &syscall.SysProcAttr{HideWindow: true}
out, _ := cmd.Output() // "\nMicrosoft Windows [Version 10.0.19041.388]\n\n" out, _ := cmd.Output() // "\nMicrosoft Windows [Version 10.0.19041.388]\n\n"
@ -26,5 +32,8 @@ func osVersionWindows() string {
if sp := strings.Index(s, " "); sp != -1 { if sp := strings.Index(s, " "); sp != -1 {
s = s[sp+1:] s = s[sp+1:]
} }
if s != "" {
winVerCache.Store(s)
}
return s // "10.0.19041.388", ideally return s // "10.0.19041.388", ideally
} }