forked from gopherjs/gopherjs
/
ioutil.go
66 lines (58 loc) · 1.14 KB
/
ioutil.go
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// +build js
package testing
import (
"bytes"
"io"
"os"
"strconv"
"sync"
"time"
)
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:]
}
// A functional copy of ioutil.TempFile, to avoid extra imports.
func tempFile(prefix string) (f *os.File, err error) {
dir := os.TempDir()
nconflict := 0
for i := 0; i < 10000; i++ {
name := dir + string(os.PathSeparator) + prefix + nextSuffix()
f, err = os.OpenFile(name, os.O_RDWR|os.O_CREATE|os.O_EXCL, 0600)
if os.IsExist(err) {
if nconflict++; nconflict > 10 {
randmu.Lock()
rand = reseed()
randmu.Unlock()
}
continue
}
break
}
return
}
func readFile(filename string) (string, error) {
f, err := os.Open(filename)
if err != nil {
return "", err
}
defer f.Close()
var buf bytes.Buffer
_, err = io.Copy(&buf, f)
if err != nil {
return "", err
}
return buf.String(), nil
}