// compute blake2 hash of message id
func (msgid MessageID) Blake2Hash() string {
h := crypto.Hash()
io.WriteString(h, msgid.String())
return strings.ToLower(fmt.Sprintf("%x", h.Sum(nil)))
}
// store attachment onto filesystem
func (fs FilesystemStorage) StoreAttachment(r io.Reader, filename string) (fpath string, err error) {
// open temp file for storage
var tf *os.File
tf, err = fs.obtainTempFile()
if err == nil {
// we have the temp file
// close tempfile when done
defer tf.Close()
// create hasher
h := crypto.Hash()
// create multiwriter
mw := io.MultiWriter(tf, h)
log.WithFields(log.Fields{
"pkg": "fs-store",
"filename": filename,
}).Debug("writing to disk")
var n int64
// write all of the reader to the multiwriter
n, err = io.Copy(mw, r)
if err == nil {
// successful write
// get file checksum
d := h.Sum(nil)
// rename file to hash + extension from filename
fpath = base32.StdEncoding.EncodeToString(d) + filepath.Ext(filename)
fpath = filepath.Join(fs.AttachmentDir(), fpath)
_, err = os.Stat(fpath)
// is that file there?
if os.IsNotExist(err) {
// it's not there, let's write it
var f *os.File
f, err = os.OpenFile(fpath, os.O_WRONLY, 0755)
if err == nil {
// file opened
defer f.Close()
// seek to beginning of tempfile
tf.Seek(0, os.SEEK_SET)
// write all of the temp file to the storage file
n, err = io.Copy(f, tf)
// if err == nil by here it's all good
l := log.WithFields(log.Fields{
"pkg": "fs-store",
"filename": filename,
"hash": d,
"filepath": fpath,
"size": n,
})
if err == nil {
l.Debug("wrote attachment to disk")
} else {
l.Error("failed to write attachment to disk", err)
}
} else {
log.WithFields(log.Fields{
"pkg": "fs-store",
"filename": filename,
"hash": d,
"filepath": fpath,
}).Error("failed to open file")
}
} else {
log.WithFields(log.Fields{
"pkg": "fs-store",
"filename": filename,
"hash": d,
"filepath": fpath,
"size": n,
}).Debug("attachment exists on disk")
}
}
} else {
log.WithFields(log.Fields{
"pkg": "fs-store",
"filename": filename,
}).Error("cannot open temp file for attachment", err)
}
return
}