func (s *SlimeExt) Retrieve(e *external.External, key, file string) error {
resp, err := http.Get(s.keyURL(key))
if err != nil {
return fmt.Errorf("Couldn't GET %v: %v", s.keyURL(key), err)
}
defer resp.Body.Close()
if resp.StatusCode < 200 || resp.StatusCode >= 300 {
return fmt.Errorf("Couldn't GET %v: %v", resp.Request.URL, resp.Status)
}
fh, err := os.OpenFile(file, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0644)
if err != nil {
return err
}
sha := sha256.New()
reader := io.TeeReader(external.NewProgressReader(resp.Body, e), sha)
_, err = io.Copy(fh, reader)
if err != nil {
fh.Close()
return err
}
err = fh.Close()
if err != nil {
return err
}
if resp.Header.Get("X-Content-SHA256") != "" {
have := sha.Sum(nil)
want, _ := hex.DecodeString(resp.Header.Get("X-Content-SHA256"))
if !bytes.Equal(have, want) {
return errors.New("bad checksum of response")
}
}
return nil
}
func (s *SlimeExt) Store(e *external.External, key, file string) error {
fh, err := os.Open(file)
if err != nil {
return err
}
defer fh.Close()
shaDone := make(chan struct{})
var sha []byte
var length int64
var shaError error
go func() {
defer close(shaDone)
hash := sha256.New()
length, shaError = io.Copy(hash, fh)
if shaError != nil {
return
}
sha = hash.Sum(nil)
_, shaError = fh.Seek(0, 0)
}()
req, err := http.NewRequest("HEAD", s.keyURL(key), nil)
if err != nil {
return fmt.Errorf("Couldn't create request for %s: %v",
s.keyURL(key), err)
}
resp, err := http.DefaultClient.Do(req)
if err != nil {
return fmt.Errorf("Couldn't HEAD %v: %v", req.URL, err)
}
resp.Body.Close()
<-shaDone
if resp.StatusCode >= 200 && resp.StatusCode < 300 {
if oldSHA := resp.Header.Get("X-Content-SHA256"); oldSHA != "" {
if strings.ToLower(oldSHA) == hex.EncodeToString(sha) {
// Key already exists with the correct data
return nil
}
}
}
req, err = http.NewRequest("PUT", s.keyURL(key),
external.NewProgressReader(fh, e))
if err != nil {
return fmt.Errorf("Couldn't create request for %s: %v",
s.keyURL(key), err)
}
req.Header.Set("X-Content-SHA256", hex.EncodeToString(sha))
req.Header.Set("Content-Length", strconv.FormatInt(length, 10))
resp, err = http.DefaultClient.Do(req)
if err != nil {
return fmt.Errorf("Couldn't PUT to %v: %v", req.URL, err)
}
resp.Body.Close()
if resp.StatusCode < 200 || resp.StatusCode >= 300 {
return fmt.Errorf("Couldn't PUT to %v: %v", req.URL, resp.Status)
}
return nil
}