forked from carlosa8c/acyl
/
tempdir.go
61 lines (54 loc) · 1.04 KB
/
tempdir.go
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package env
import (
"os"
"path/filepath"
"strconv"
"sync"
"time"
billy "gopkg.in/src-d/go-billy.v4"
)
var rand uint32
var randmu sync.Mutex
func reseed() uint32 {
return uint32(time.Now().UnixNano() + int64(os.Getpid()))
}
func nextSuffix() string {
randmu.Lock()
r := rand
if r == 0 {
r = reseed()
}
r = r*1664525 + 1013904223 // constants from Numerical Recipes
rand = r
randmu.Unlock()
return strconv.Itoa(int(1e9 + r%1e9))[1:]
}
// tempDir is copypasta from ioutil.TempDir that uses a supplied FS
func tempDir(fs billy.Filesystem, dir, prefix string) (name string, err error) {
if dir == "" {
dir = "/tmp/"
}
nconflict := 0
for i := 0; i < 10000; i++ {
try := filepath.Join(dir, prefix+nextSuffix())
err = fs.MkdirAll(try, 0700)
if os.IsExist(err) {
if nconflict++; nconflict > 10 {
randmu.Lock()
rand = reseed()
randmu.Unlock()
}
continue
}
if os.IsNotExist(err) {
if _, err := fs.Stat(dir); os.IsNotExist(err) {
return "", err
}
}
if err == nil {
name = try
}
break
}
return
}